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Electron transport chain
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The electron transport chain in the mitochondrion is the site of oxidative phosphorylation in eukaryotes. The NADH and succinate generated in the citric acid cycle are oxidized, providing energy to power ATP synthase.
Photosynthetic electron transport chain of the thylakoid membrane.
An electron transport chain (ETC) is a series of complexes that transfer electrons from electron donors to electron acceptors via redox (both reduction and oxidation occurring simultaneously) reactions, and couples this electron transfer with the transfer of protons (H+ ions) across a membrane. This creates an electrochemical proton gradient that drives the synthesis of adenosine triphosphate (ATP), a molecule that stores energy chemically in the form of highly strained bonds. The molecules of the chain include peptides, enzymes (which are proteins or protein complexes), and others. The final acceptor of electrons in the electron transport chain during aerobic respiration is molecular oxygen although a variety of acceptors other than oxygen such as sulfate exist in anaerobic respiration.
Electron transport chains are used for extracting energy via redox reactions from sunlight in photosynthesis or, such as in the case of the oxidation of sugars, cellular respiration. In eukaryotes, an important electron transport chain is found in the inner mitochondrial membrane where it serves as the site of oxidative phosphorylation through the use of ATP synthase. It is also found in the thylakoid membrane of the chloroplast in photosynthetic eukaryotes. In bacteria, the electron transport chain is located in their cell membrane.
In chloroplasts, light drives the conversion of water to oxygen and NADP+ to NADPH with transfer of H+ ions across chloroplast membranes. In mitochondria, it is the conversion of oxygen to water, NADH to NAD+ and succinate to fumarate that are required to generate the proton gradient.
Electron transport chains are major sites of premature electron leakage to oxygen, generating superoxide and potentially resulting in increased oxidative stress.
Contents
[hide]
1 Background
2 In mitochondria
2.1 Mitochondrial redox carriers
2.1.1 Complex I
2.1.2 Complex II
2.1.3 Complex III
2.1.4 Complex IV
2.2 Coupling with oxidative phosphorylation
2.3 Summary
3 In bacteria
3.1 Electron donors
3.2 Dehydrogenases
3.3 Quinone carriers
3.4 Proton pumps
3.5 Cytochrome electron carriers
3.6 Terminal oxidases and reductases
3.7 Electron acceptors
3.8 Summary
4 Photosynthetic
5 Summary
6 See also
7 References
8 External links
Background[edit]
The electron transport chain consists of a spatially separated series of redox reactions in which electrons are transferred from a donor molecule to an acceptor molecule. The underlying force driving these reactions is the Gibbs free energy of the reactants and products. The Gibbs free energy is the energy available ("free") to do work. Any reaction that decreases the overall Gibbs free energy of a system is thermodynamically spontaneous.
The function of the electron transport chain is to produce a transmembrane proton electrochemical gradient as a result of the redox reactions.[1] If protons flow back through the membrane, they enable mechanical work, such as rotating bacterial flagella. ATP synthase, an enzyme highly conserved among all domains of life, converts this mechanical work into chemical energy by producing ATP,[2] which powers most cellular reactions. A small amount of ATP is available from substrate-level phosphorylation, for example, in glycolysis. In most organisms the majority of ATP is generated in electron transport chains, while only some obtain ATP by fermentation.[citation needed]
In mitochondria[edit]
Most eukaryotic cells have mitochondria, which produce ATP from products of the citric acid cycle, fatty acid oxidation, and amino acid oxidation. At the mitochondrial inner membrane, electrons from NADH and FADH2 pass through the electron transport chain to oxygen, which is reduced to water. The electron transport chain comprises an enzymatic series of electron donors and acceptors. Each electron donor will pass electrons to a more electronegative acceptor, which in turn donates these electrons to another acceptor, a process that continues down the series until electrons are passed to oxygen, the most electronegative and terminal electron acceptor in the chain. Passage of electrons between donor and acceptor releases energy, which is used to generate a proton gradient across the mitochondrial membrane by actively "pumping" protons into the intermembrane space, producing a thermodynamic state that has the potential to do work. The entire process is called oxidative phosphorylation, since ADP is phosphorylated to ATP using the energy of hydrogen oxidation in many steps.
A small percentage of electrons do not complete the whole series and instead directly leak to oxygen, resulting in the formation of the free-radical superoxide, a highly reactive molecule that contributes to oxidative stress and has been implicated in a number of diseases and aging.
Mitochondrial redox carriers[edit]
Energy obtained through the transfer of electrons down the ETC is used to pump protons from the mitochondrial matrix into the intermembrane space, creating an electrochemical proton gradient (ΔpH) across the inner mitochondrial membrane (IMM). This proton gradient is largely but not exclusively responsible for the mitochondrial membrane potential (ΔΨM). It allows ATP synthase to use the flow of H+ through the enzyme back into the matrix to generate ATP from adenosine diphosphate (ADP) and inorganic phosphate. Complex I (NADH coenzyme Q reductase; labeled I) accepts electrons from the Krebs cycle electron carrier nicotinamide adenine dinucleotide (NADH), and passes them to coenzyme Q (ubiquinone; labeled Q), which also receives electrons from complex II (succinate dehydrogenase; labeled II). Q passes electrons to complex III (cytochrome bc1 complex; labeled III), which passes them to cytochrome c (cyt c). Cyt c passes electrons to Complex IV (cytochrome c oxidase; labeled IV), which uses the electrons and hydrogen ions to reduce molecular oxygen to water.
Four membrane-bound complexes have been identified in mitochondria. Each is an extremely complex transmembrane structure that is embedded in the inner membrane. Three of them are proton pumps. The structures are electrically connected by lipid-soluble electron carriers and water-soluble electron carriers. The overall electron transport chain:
NADH+H+ → Complex I → Q → Complex III → cytochrome c → Complex IV → H2O ↑ Complex II ↑ Succinate

Complex I[edit]
In Complex I (NADH:ubiquinone oxidoreductase, NADH-CoQ reductase, or NADH dehydrogenase; EC 1.6.5.3), two electrons are removed from NADH and ultimately transferred to a lipid-soluble carrier, ubiquinone (Q). The reduced product, ubiquinol (QH2), freely diffuses within the membrane, and Complex I translocates four protons (H+) across the membrane, thus producing a proton gradient. Complex I is one of the main sites at which premature electron leakage to oxygen occurs, thus being one of the main sites of production of superoxide.[3]
The pathway of electrons is as follows:
NADH is oxidized to NAD+, by reducing Flavin mononucleotide to FMNH2 in one two-electron step. FMNH2 is then oxidized in two one-electron steps, through a semiquinone intermediate. Each electron thus transfers from the FMNH2 to an Fe-S cluster, from the Fe-S cluster to ubiquinone (Q). Transfer of the first electron results in the free-radical (semiquinone) form of Q, and transfer of the second electron reduces the semiquinone form to the ubiquinol form, QH2. During this process, four protons are translocated from the mitochondrial matrix to the intermembrane space. [4] As the electrons become continuously oxidized and reduced throughout the complex an electron current is produced along the 180 Angstrom width of the complex within the membrane. This current powers the active transport of four protons to the intermembrane space per two electrons from NADH.[5]
Complex II[edit]
In Complex II (succinate dehydrogenase or succinate-CoQ reductase; EC 1.3.5.1) additional electrons are delivered into the quinone pool (Q) originating from succinate and transferred (via flavin adenine dinucleotide (FAD)) to Q. Complex II consists of four protein subunits: succinate dehydrogenase, (SDHA); succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial, (SDHB); succinate dehydrogenase complex subunit C, (SDHC) and succinate dehydrogenase complex, subunit D, (SDHD). Other electron donors (e.g., fatty acids and glycerol 3-phosphate) also direct electrons into Q (via FAD). Complex 2 is a parallel electron transport pathway to complex 1, but unlike complex 1, no protons are transported to the intermembrane space in this pathway. Therefore, the pathway through complex 2 contributes less energy to the overall electron transport chain process.
Complex III[edit]
In Complex III (cytochrome bc1 complex or CoQH2-cytochrome c reductase; EC 1.10.2.2), the Q-cycle contributes to the proton gradient by an asymmetric absorption/release of protons. Two electrons are removed from QH2 at the QO site and sequentially transferred to two molecules of cytochrome c, a water-soluble electron carrier located within the intermembrane space. The two other electrons sequentially pass across the protein to the Qi site where the quinone part of ubiquinone is reduced to quinol. A proton gradient is formed by one quinol (2H+2e-) oxidations at the Qo site to form one quinone (2H+2e-) at the Qi site. (in total four protons are translocated: two protons reduce quinone to quinol and two protons are released from two ubiquinol molecules).
 QH2 + 2 cytochrome c (FeIII) + 2 H+in → Q + 2 cytochrome c (FeII) + 4 H+out

When electron transfer is reduced (by a high membrane potential or respiratory inhibitors such as antimycin A), Complex III may leak electrons to molecular oxygen, resulting in superoxide formation.
Complex IV[edit]
In Complex IV (cytochrome c oxidase; EC 1.9.3.1), sometimes called cytochrome AA3, four electrons are removed from four molecules of cytochrome c and transferred to molecular oxygen (O2), producing two molecules of water. At the same time, eight protons are removed from the mitochondrial matrix (although only four are translocated across the membrane), contributing to the proton gradient. The activity of cytochrome c oxidase is inhibited by cyanide.
Coupling with oxidative phosphorylation[edit]
Depiction of ATP synthase, the site of oxidative phosphorylation to generate ATP.
According to the chemiosmotic coupling hypothesis, proposed by Nobel Prize in Chemistry winner Peter D. Mitchell, the electron transport chain and oxidative phosphorylation are coupled by a proton gradient across the inner mitochondrial membrane. The efflux of protons from the mitochondrial matrix creates an electrochemical gradient (proton gradient). This gradient is used by the FOF1 ATP synthase complex to make ATP via oxidative phosphorylation. ATP synthase is sometimes described as Complex V of the electron transport chain.[6] The FO component of ATP synthase acts as an ion channel that provides for a proton flux back into the mitochondrial matrix. It is composed of a, b and c subunits. Protons in the inter-membranous space of mitochondria first enters the ATP synthase complex through a subunit channel. Then protons move to the c subunits.[7] The number of c subunits it has determines how many protons it will require to make the FO turn one full revolution. For example, in humans, there are 8 c subunits, thus 8 protons are required.[8] After c subunits, protons finally enters matrix using a subunit channel that opens into the mitochondrial matrix.[7] This reflux releases free energy produced during the generation of the oxidized forms of the electron carriers (NAD+ and Q). The free energy is used to drive ATP synthesis, catalyzed by the F1 component of the complex.[9]
Coupling with oxidative phosphorylation is a key step for ATP production. However, in specific cases, uncoupling the two processes may be biologically useful. The uncoupling protein, thermogenin—present in the inner mitochondrial membrane of brown adipose tissue—provides for an alternative flow of protons back to the inner mitochondrial matrix. This alternative flow results in thermogenesis rather than ATP production.[10] Synthetic uncouplers (e.g., 2,4-dinitrophenol) also exist, and, at high doses, are lethal.[citation needed]
Summary[edit]
In the mitochondrial electron transport chain electrons move from an electron donor (NADH or QH2) to a terminal electron acceptor (O2) via a series of redox reactions. These reactions are coupled to the creation of a proton gradient across the mitochondrial inner membrane. There are three proton pumps: I, III, and IV. The resulting transmembrane proton gradient is used to make ATP via ATP synthase.
The reactions catalyzed by Complex I and Complex III work roughly at equilibrium. This means that these reactions are readily reversible, by increasing the concentration of the products relative to the concentration of the reactants (for example, by increasing the proton gradient). ATP synthase is also readily reversible. Thus ATP can be used to build a proton gradient, which in turn can be used to make NADH. This process of reverse electron transport is important in many prokaryotic electron transport chains.[11]
In bacteria[edit]
In eukaryotes, NADH is the most important electron donor. The associated electron transport chain is
NADH → Complex I → Q → Complex III → cytochrome c → Complex IV → O2 where Complexes I, III and IV are proton pumps, while Q and cytochrome c are mobile electron carriers. The electron acceptor is molecular oxygen.
In prokaryotes (bacteria and archaea) the situation is more complicated, because there are several different electron donors and several different electron acceptors. The generalized electron transport chain in bacteria is:
                     Donor Donor Donor ↓ ↓ ↓ dehydrogenase → quinone → bc1 → cytochrome ↓ ↓ oxidase(reductase) oxidase(reductase) ↓ ↓ Acceptor Acceptor

Note that electrons can enter the chain at three levels: at the level of a dehydrogenase, at the level of the quinone pool, or at the level of a mobile cytochrome electron carrier. These levels correspond to successively more positive redox potentials, or to successively decreased potential differences relative to the terminal electron acceptor. In other words, they correspond to successively smaller Gibbs free energy changes for the overall redox reaction Donor → Acceptor.
Individual bacteria use multiple electron transport chains, often simultaneously. Bacteria can use a number of different electron donors, a number of different dehydrogenases, a number of different oxidases and reductases, and a number of different electron acceptors. For example, E. coli (when growing aerobically using glucose as an energy source) uses two different NADH dehydrogenases and two different quinol oxidases, for a total of four different electron transport chains operating simultaneously.
A common feature of all electron transport chains is the presence of a proton pump to create a transmembrane proton gradient. Bacterial electron transport chains may contain as many as three proton pumps, like mitochondria, or they may contain only one or two. They always contain at least one proton pump.
Electron donors[edit]
In the present day biosphere, the most common electron donors are organic molecules. Organisms that use organic molecules as an energy source are called organotrophs. Organotrophs (animals, fungi, protists) and phototrophs (plants and algae) constitute the vast majority of all familiar life forms.
Some prokaryotes can use inorganic matter as an energy source. Such an organism is called a lithotroph ("rock-eater"). Inorganic electron donors include hydrogen, carbon monoxide, ammonia, nitrite, sulfur, sulfide, manganese oxide, and ferrous iron. Lithotrophs have been found growing in rock formations thousands of meters below the surface of Earth. Because of their volume of distribution, lithotrophs may actually outnumber organotrophs and phototrophs in our biosphere.
The use of inorganic electron donors as an energy source is of particular interest in the study of evolution. This type of metabolism must logically have preceded the use of organic molecules as an energy source.
Dehydrogenases[edit]
Bacteria can use a number of different electron donors. When organic matter is the energy source, the donor may be NADH or succinate, in which case electrons enter the electron transport chain via NADH dehydrogenase (similar to Complex I in mitochondria) or succinate dehydrogenase (similar to Complex II). Other dehydrogenases may be used to process different energy sources: formate dehydrogenase, lactate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, H2 dehydrogenase (hydrogenase), etc. Some dehydrogenases are also proton pumps; others funnel electrons into the quinone pool. Most dehydrogenases show induced expression in the bacterial cell in response to metabolic needs triggered by the environment in which the cells grow.[citation needed]
Quinone carriers[edit]
Quinones are mobile, lipid-soluble carriers that shuttle electrons (and protons) between large, relatively immobile macromolecular complexes embedded in the membrane. Bacteria use ubiquinone (the same quinone that mitochondria use) and related quinones such as menaquinone. Another name for ubiquinone is Coenzyme Q10.
Proton pumps[edit]
A proton pump is any process that creates a proton gradient across a membrane. Protons can be physically moved across a membrane; this is seen in mitochondrial Complexes I and IV. The same effect can be produced by moving electrons in the opposite direction. The result is the disappearance of a proton from the cytoplasm and the appearance of a proton in the periplasm. Mitochondrial Complex III uses this second type of proton pump, which is mediated by a quinone (the Q cycle).
Some dehydrogenases are proton pumps; others are not. Most oxidases and reductases are proton pumps, but some are not. Cytochrome bc1 is a proton pump found in many, but not all, bacteria (it is not found in E. coli). As the name implies, bacterial bc1 is similar to mitochondrial bc1 (Complex III).
Proton pumps are the heart of the electron transport process. They produce the transmembrane electrochemical gradient that enables ATP Synthase to synthesize ATP.
Cytochrome electron carriers[edit]
Cytochromes are pigments that contain iron. They are found in two very different environments.
Some cytochromes are water-soluble carriers that shuttle electrons to and from large, immobile macromolecular structures imbedded in the membrane. The mobile cytochrome electron carrier in mitochondria is cytochrome c. Bacteria use a number of different mobile cytochrome electron carriers.
Other cytochromes are found within macromolecules such as Complex III and Complex IV. They also function as electron carriers, but in a very different, intramolecular, solid-state environment.
Electrons may enter an electron transport chain at the level of a mobile cytochrome or quinone carrier. For example, electrons from inorganic electron donors (nitrite, ferrous iron, etc.) enter the electron transport chain at the cytochrome level. When electrons enter at a redox level greater than NADH, the electron transport chain must operate in reverse to produce this necessary, higher-energy molecule.
Terminal oxidases and reductases[edit]
When bacteria grow in aerobic environments, the terminal electron acceptor (O2) is reduced to water by an enzyme called an oxidase. When bacteria grow in anaerobic environments, the terminal electron acceptor is reduced by an enzyme called a reductase.
In mitochondria the terminal membrane complex (Complex IV) is cytochrome oxidase. Aerobic bacteria use a number of different terminal oxidases. For example, E. coli does not have a cytochrome oxidase or a bc1 complex. Under aerobic conditions, it uses two different terminal quinol oxidases (both proton pumps) to reduce oxygen to water.
Anaerobic bacteria, which do not use oxygen as a terminal electron acceptor, have terminal reductases individualized to their terminal acceptor. For example, E. coli can use fumarate reductase, nitrate reductase, nitrite reductase, DMSO reductase, or trimethylamine-N-oxide reductase, depending on the availability of these acceptors in the environment.
Most terminal oxidases and reductases are inducible. They are synthesized by the organism as needed, in response to specific environmental conditions.
Electron acceptors[edit]
Just as there are a number of different electron donors (organic matter in organotrophs, inorganic matter in lithotrophs), there are a number of different electron acceptors, both organic and inorganic. If oxygen is available, it is invariably used as the terminal electron acceptor, because it generates the greatest Gibbs free energy change and produces the most energy.[citation needed]
In anaerobic environments, different electron acceptors are used, including nitrate, nitrite, ferric iron, sulfate, carbon dioxide, and small organic molecules such as fumarate.
Since electron transport chains are redox processes, they can be described as the sum of two redox pairs. For example, the mitochondrial electron transport chain can be described as the sum of the NAD+/NADH redox pair and the O2/H2O redox pair. NADH is the electron donor and O2 is the electron acceptor.
Not every donor-acceptor combination is thermodynamically possible. The redox potential of the acceptor must be more positive than the redox potential of the donor. Furthermore, actual environmental conditions may be far different from standard conditions (1 molar concentrations, 1 atm partial pressures, pH = 7), which apply to standard redox potentials. For example, hydrogen-evolving bacteria grow at an ambient partial pressure of hydrogen gas of 10−4 atm. The associated redox reaction, which is thermodynamically favorable in nature, is thermodynamic impossible under "standard" conditions.[citation needed]
Summary[edit]
Bacterial electron transport pathways are, in general, inducible. Depending on their environment, bacteria can synthesize different transmembrane complexes and produce different electron transport chains in their cell membranes. Bacteria select their electron transport chains from a DNA library containing multiple possible dehydrogenases, terminal oxidases and terminal reductases. The situation is often summarized by saying that electron transport chains in bacteria are branched, modular, and inducible.
Photosynthetic[edit]
In oxidative phosphorylation, electrons are transferred from a low-energy electron donor (e.g., NADH) to an acceptor (e.g., O2) through an electron transport chain. In photophosphorylation, the energy of sunlight is used to create a high-energy electron donor and an electron acceptor. Electrons are then transferred from the donor to the acceptor through another electron transport chain.
Photosynthetic electron transport chains have many similarities to the oxidative chains discussed above. They use mobile, lipid-soluble carriers (quinones) and mobile, water-soluble carriers (cytochromes, etc.). They also contain a proton pump. It is remarkable that the proton pump in all photosynthetic chains resembles mitochondrial Complex III.
Photosynthetic electron transport chains are discussed in greater detail in the articles Photophosphorylation, Photosynthesis, Photosynthetic reaction center and Light-dependent reaction.
Summary[edit]
Electron transport chains are redox reactions that transfer electrons from an electron donor to an electron acceptor. The transfer of electrons is coupled to the translocation of protons across a membrane, producing a proton gradient. The proton gradient is used to produce useful work. About 30 work units are produced per electron transport.
See also[edit]
CoRR hypothesis
Electron equivalent
Hydrogen hypothesis
Respirasome
References[edit]
Jump up ^ Murray, Robert K.; Daryl K. Granner; Peter A. Mayes; Victor W. Rodwell (2003). Harper's Illustrated Biochemistry. New York, NY: Lange Medical Books/ MgGraw Hill. p. 96. ISBN 0-07-121766-5.
Jump up ^ Karp, Gerald (2008). Cell and Molecular Biology (5th ed.). Hoboken, NJ: John Wiley & Sons. p. 194. ISBN 978-0-470-04217-5.
Jump up ^ Lauren, Biochemistry, Johnson/Cole, 2010, pp 598-611
Jump up ^ Garrett & Grisham, Biochemistry, Brooks/Cole, 2010, pp 598-611
Jump up ^ Garret and Grisham (2016). biochemistry. University of Virginia. p. 687. ISBN 978-1-305-57720-6.
Jump up ^ Jonckheere, An I.; Smeitink, Jan A. M.; Rodenburg, Richard J. T. (2017-03-10). "Mitochondrial ATP synthase: architecture, function and pathology". Journal of Inherited Metabolic Disease. 35 (2): 211–225. ISSN 0141-8955. PMC 3278611  . PMID 21874297. doi:10.1007/s10545-011-9382-9.
^ Jump up to: a b Garrett, Reginald H.; Grisham, Charles M. (2012). Biochemistry (5th ed.). Cengage learning. p. 664. ISBN 1-133-10629-3.
Jump up ^ Fillingame, Robert H; Angevine, Christine M; Dmitriev, Oleg Y (2003-11-27). "Mechanics of coupling proton movements to c-ring rotation in ATP synthase". FEBS Letters. 555 (1): 29–34. ISSN 1873-3468. doi:10.1016/S0014-5793(03)01101-3.
Jump up ^ Berg, Jeremy M.; Tymoczko, John L.; Stryer, Lubert (2002-01-01). "A Proton Gradient Powers the Synthesis of ATP".
Jump up ^ Cannon, Barbara; Nedergaard, Jan (2004-01-01). "Brown Adipose Tissue: Function and Physiological Significance". Physiological Reviews. 84 (1): 277–359. ISSN 0031-9333. PMID 14715917. doi:10.1152/physrev.00015.2003.
Jump up ^ Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; Walter, Peter (2002-01-01). "Electron-Transport Chains and Their Proton Pumps".
Fenchel T; King GM; Blackburn TH (September 2006). Bacterial Biogeochemistry: The Ecophysiology of Mineral Cycling (2nd ed.). Elsevier. ISBN 978-0-12-103455-9.
Lengeler JW (January 1999). Drews G; Schlegel HG, eds. Biology of the Prokaryotes. Blackwell Science. ISBN 978-0-632-05357-5.
Nelson DL; Cox MM (April 2005). Lehninger Principles of Biochemistry (4th ed.). W. H. Freeman. ISBN 978-0-7167-4339-2.
Nicholls DG; Ferguson SJ (July 2002). Bioenergetics 3. Academic Press. ISBN 978-0-12-518121-1.
Stumm W; Morgan JJ (1996). Aquatic Chemistry (3rd ed.). John Wiley & Sons. ISBN 978-0-471-51185-4.
Thauer RK; Jungermann K; Decker K (March 1977). "Energy conservation in chemotrophic anaerobic bacteria". Bacteriol Rev. 41 (1): 100–80. PMC 413997  . PMID 860983.
White D. (September 1999). The Physiology and Biochemistry of Prokaryotes (2nd ed.). Oxford University Press. ISBN 978-0-19-512579-5.
Voet D; Voet JG (March 2004). Biochemistry (3rd ed.). John Wiley & Sons. ISBN 978-0-471-58651-7.
Kim HS.; Patel, K; Muldoon-Jacobs, K; Bisht, KS; Aykin-Burns, N; Pennington, JD; Van Der Meer, R; Nguyen, P; et al. (January 2010). "SIRT3 is a mitochondria-localized tumor suppressor required for maintenance of mitochondrial integrity and metabolism during stress". Cancer Cell. 17 (1): 41–52. PMC 3711519  . PMID 20129246. doi:10.1016/j.ccr.2009.11.023.
External links[edit]
Electron Transport Chain Complex Proteins at the US National Library of Medicine Medical Subject Headings (MeSH)
Khan Academy, video lecture
UMich Orientation of Proteins in Membranes families/superfamily-3 - Complexes with cytochrome b-like domains
UMich Orientation of Proteins in Membranes families/superfamily-4 - Bacterial and mitochondrial cytochrome c oxidases
UMich Orientation of Proteins in Membranes families/superfamily-2 - Photosynthetic reaction centers and photosystems
UMich Orientation of Proteins in Membranes families/superfamily-78 - Cytochrome PORN renodoxin reductase
UMich Orientation of Proteins in Membranes families/superfamily-130 - Electron transfer flavoproteins
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Bright (film)
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Bright
Film release poster
Directed by
David Ayer
Produced by
David Ayer
Eric Newman
Ted Sarandos
Bryan Unkeless
Written by
Max Landis
Starring
Will Smith
Joel Edgerton
Noomi Rapace
Lucy Fry
Édgar Ramírez
Ike Barinholtz
Music by
David Sardy
Cinematography
Roman Vasyanov
Edited by
Michael Tronick
Geoffrey O'Brien
Aaron Brock
Production
company
Overbrook Entertainment
Trigger Warning Entertainment
Grand Electric
Netflix
Distributed by
Netflix
Release date
December 13, 2017 (2017-12-13) (Regency Village Theater)
December 22, 2017 (2017-12-22) (United States)
Running time
118 minutes
Country
United States
Language
English
Budget
$90 million[1]
Bright is a 2017 American urban fantasy crime film directed by David Ayer and written by Max Landis.[2][3] The film stars Will Smith as a Los Angeles Police Department police officer who teams up with an orc rookie police officer (Joel Edgerton) in a world of both human and mythical creatures.[4] It also stars Noomi Rapace, Lucy Fry, Édgar Ramírez, and Ike Barinholtz.
Principal photography began in November 2016 in Los Angeles. The film was released worldwide on Netflix on December 22, 2017, and became one of the site's most streamed programs ever, although it received negative reviews from critics.[5]
Contents
[hide]
1 Plot
2 Cast
3 Production
3.1 Filming
4 Reception
4.1 Critical response
4.2 Audience response
5 Soundtrack
5.1 Charts
6 Sequel
7 See also
8 References
9 External links
Plot[edit]
In an alternate present, humans live in uneasy peace with orcs, elves, centaurs, dwarves and other races after they fought for thousands of years. In Los Angeles, veteran LAPD police officer Daryl Ward has been involuntarily partnered with Nick Jakoby, the nation's first orcish police officer. Jakoby is faced with prejudice by humans for his race, and by orcs for his position as an officer. In addition to the pushback from other officers, Ward is ambivalent towards him after an incident where Ward was nearly killed by a shotgun-wielding orc and Jakoby had apparently let the assailant get away. While driving back to the station, a previously detained human Shield of Light devotee tells Jakoby in Orcish that both officers are in a prophecy and that Ward is blessed. While Jakoby is booking the devotee, Ward is approached by Internal Affairs who say they believe that Jakoby put his racial loyalties before his partner in allowing the orc assailant to get away. Ward is pressured to try to have Jakoby confess on tape so they will have publicly acceptable grounds for a firing.
That night, Ward and Jakoby respond to a disturbance at what turns out to be a Shield of Light safe house; inside are a number of smoldering corpses, and the still-living torso of an elf woman embedded in a wall, indicating magic was used. They apprehend the lone unhurt survivor, a young elf named Tikka in possession of a legendary magic wand who apparently only speaks Elfish. As Jakoby puts it, a wand is like "a nuclear weapon that grants wishes", and can only be commanded by a 'Bright'—a person with the rare ability to use magic. If a non-Bright touches a wand, they will explode from the raw magical power.
When four officers arrive as backup, their racial prejudice cause them to try and coerce Ward into killing Jakoby and lying about the incident, telling Ward he will be spared in return and allowing them to steal the wand. They allow Ward to decide and he goes outside to Jakoby, holds him at gunpoint, and begins questioning him about the orc that had shot him. Jakoby admits to letting the suspect escape, though the reason being was that he had mistakenly cornered the wrong suspect. Jakoby had lost the original orc in the crowd and had instead caught up with a young orc who was spray painting a wall, not the orc who had tried to kill Ward, but he knew the other officers would not believe it and so let the kid go. During this confrontation, the four officers secretly plan on killing Ward after he kills Jakoby. As they approach Ward to hear his decision, Ward suddenly decides to believe Jakoby and kills all four officers. The incident, however, attracts the attention of the local human gang Altamira, and the two flee, under heavy fire, with Tikka and the wand. Leilah, a member of the ominous group Inferni and owner of the wand, arrives at the safehouse minutes later, searching for the wand and Tikka.
After a pursuit, the trio flee through the territory of the Fogteeth Orc clan, causing a violent confrontation between the gang and the clan. Finally cornered in a strip club, the gang's disabled leader, Poison, wanting to regain the use of his legs using the wand, threatens to burn the building down unless the officers give up the wand. As Jakoby and Ward pull out their weapons to give a final stand, the Inferni appear and the ensuing fight gives the trio the opportunity to escape again. Going to ground in a service station, Ward contacts his friend, Sheriff Deputy Rodriguez, who he hopes will help them in protecting the wand. Rodriguez contacts Kandomere, an elf working for the federal 'Magic Task Force'; dedicated to securing, containing and protecting magical objects. Kandomere tells Ward that he will be safe from prosecution for killing his fellow police officers, if they can keep the wand out of wrong hands. Before Rodriguez can bring them in, Leilah's henchmen attack the trio, killing him.
Ward, Jakoby, and Tikka run into the Fogteeth Orc clan again and are dragged before its leader Dorghu. Enraged at the chaos they are causing in his neutral territory, Dorghu has Jakoby and Ward beaten and tortured to reveal the location of the wand. Dorghu orders his son, Mikey, to kill Jakoby after failing to get an answer. However, Mikey reveals that he was the orc that Jakoby allowed to escape and thus refuses to kill him. Dorghu sends his son away and kills Jakoby himself, who falls dead into a deep pit. As he prepares to kill Ward as well, Tikka produces the wand she had magically hidden and uses it to resurrect Jakoby, revealing that she is a Bright, leaving herself incapacitated. The cloaked clan priest pronounces this to be the will of the Prophecy, causing the clan kneel to Jakoby and allow the trio to go free. Realizing that the two officers can now be trusted, Tikka speaks to them in English for the first time. She explains the Inferni's plan to resurrect The Dark Lord, an ancient mythical figure who will rise from the dead and take over the world. Once a member of the Inferni herself, Tikka had been protected by the Shield of Light and fled with the wand.
The use of the wand causes Tikka to become ill with black streaks appearing all over her body. She says that the only way to save her is to place her in a magic pool back at the Shield safe house. They return to the safehouse, but are ambushed by Leilah and the remaining Inferni. The trio successfully kill the Inferni, but Leilah is resurrected by a magic spell. Just as Ward places Tikka in the magic pool, Leilah hangs Jakoby and knocks both Ward and Tikka out of the pool. Leilah unsuccessfully tries to convince Tikka to join her (revealing they are sisters). Jakoby breaks free and shoots the wand out of Leilah's hand, but runs out of ammo before he can kill her again. Leilah is about to kill Tikka when Ward picks up the fallen wand and is revealed to also be a Bright, using the wand to kill Leilah with an explosion that sets the building on fire. In the ensuing commotion, Tikka disappears and the injured Ward and Jakoby flee from the building, but Ward falls behind and is trapped by an explosion, causing Jakoby to have to return and save him. After rescuing Ward, Dorghu and his clan appear and perform an ancient orc ceremony signifying to Jakoby that he is now "blooded" - an Orcish status only achievable by an act of great bravery.
Ward awakens the next day in a hospital room to find Jakoby at his bedside and himself restrained as he is an "extremely dangerous" Bright. As Kandomere appears, Ward understands (but Jakoby does not) that Kandomere wants to contain the incident, and gives him a fake statement as to what happened, denying the use of magic. In a public announcement before a crowd, Jakoby and Ward are honored by the city for their actions against the 'extremist group' Inferni. Ward smiles as he spots Tikka moving through the crowd in disguise.
Cast[edit]
Will Smith as Daryl Ward, a human LAPD officer.
Joel Edgerton as Nick Jakoby, the nation's first Orcish police officer, who is partnered with Daryl.
Noomi Rapace as Leilah, an Inferni elf seeking control of the magic wand.
Lucy Fry as Tikka, a young Inferni elf who is in possession of the magic wand.
Édgar Ramírez as Kandomere, a high ranking elvish federal agent with the US Department of Magic's Magic Task Force.
Ike Barinholtz as Pollard, a corrupt human LAPD officer who seeks to steal the wand for himself.
Happy Anderson as Hildebrandt Ulysses Montehugh, a human federal agent who works under Kandomere in the Magic Task Force.
Dawn Olivieri as Sherri Ward, Daryl's human wife and Sophia's mother.
Matt Gerald as Hicks, a corrupt human LAPD officer.
Margaret Cho as Ching, a corrupt human LAPD sergeant.
Brad William Henke as Dorghu, the imposing leader of the Fogteeth Orcs gang.
Jay Hernandez as Rodriguez, a human LACSD deputy.
Veronica Ngo as Tien, an Inferni elf enforcer working for Leilah.
Alex Meraz as Serafin, an Inferni elf enforcer working for Leilah.
Joseph Piccuirro as Brown, a corrupt human LAPD officer.
Enrique Murciano as Poison, the wheelchair bound leader of the human Altamira gang.
Scarlet Spencer as Sophia Ward, Daryl and Sherri's human daughter.
Andrea Navedo as Perez, a human LAPD captain and Ward's superior.
Kenneth Choi as Yamahara, a human LAPD internal affairs detective.
Bobby Naderi as Arkashian, a human LAPD internal affairs detective.
Cle Shaheed Sloan as OG Mike, the Wards' human neighbor.
Chris Browning as Serling, a human questioned by the US Department of Magic's Task Force.
Joe Rogan as himself
Production[edit]
(L–R): Director David Ayer and stars Noomi Rapace, Joel Edgerton, Will Smith, Édgar Ramírez, and Lucy Fry at the 2017 San Diego Comic-Con
Described as "a contemporary cop thriller, but with fantastical elements", the film is directed by David Ayer and stars Will Smith and Joel Edgerton, with a script penned by Max Landis, which Ayer rewrote.[2][3] Netflix officially picked up the film for a $90 million deal with filming beginning in fall 2016, making it the most expensive Netflix film to date.[6] Noomi Rapace entered talks to join the cast in May 2016.[7] Landis stated in an interview that official production was expected to begin in September 2016, but that they'd already shot a small part in Los Angeles.[8] Ayer's frequent cinematographer, Roman Vasyanov, was confirmed to be working on the project.[9] On October 15, 2016, Lucy Fry was added to the cast.[10] On October 17, 2016, Andrea Navedo was added to the cast.[11] On October 20, 2016, actor Brad William Henke was cast in the film.[12] On November 1, 2016, Kenneth Choi and Dawn Olivieri were cast in an unknown role and the role of Smith's wife, respectively.[13] On November 9, Édgar Ramírez was confirmed to be added to the cast.[14] That same month, Alex Meraz, Matt Gerald, Ike Barinholtz, and Enrique Murciano joined the cast of the film in undisclosed roles.[15][16][17][18]
Filming[edit]
Photos from the set were first published in November 2016.[19][20] Filming was completed by February 4, 2017.[21]
Reception[edit]
Critical response[edit]
Bright received criticism for its screenplay, cinematography and excessive focus on social commentary.[5] On Rotten Tomatoes, the film has an approval rating of 26% based on 91 reviews, with an average rating of 3.8/10. The website's critical consensus reads, "Bright tries to blend fantasy, hard-hitting cop drama, and social commentary—and ends up falling painfully short of the mark on all three fronts."[22] On Metacritic the film has a weighted average score of 29 out of 100, based on 26 critics, indicating "generally unfavorable reviews".[23]
Richard Roeper of the Chicago Sun-Times gave the film 1.5 out of 4 stars, saying: "Bright is basically a tired buddy-cop movie dressed up in bizarre trappings ... It doesn’t take itself too seriously, but it’s not nearly as self-deprecating and funny as it needed to be."[24] Writing for Rolling Stone, David Fear gave the film 1 out of 4 stars, criticizing the script and incoherent action scenes, writing: "This combo of gritty cop procedural and fantasy is a dark, dank, dumb-as-hell mess."[25]
David Ehrlich of IndieWire gave the film an "F" and called it the worst film of 2017, saying: "There's boring, there's bad, and then there's Bright ... from the director of Suicide Squad and the writer of Victor Frankenstein comes a fresh slice of hell that somehow represents new lows for them both—a dull and painfully derivative ordeal that often feels like it was made just to put those earlier misfires into perspective."[26] Ayer responded enthusiastically to Ehrlich's review, claiming that he desired for the film to receive "a strong reaction either way."[27]
NPR's Chris Klimek wrote: "Critics have already lined up to pillory Bright as among the year's worst releases. Don't believe the clickbait. Lazy but not boring, this Net-flick is perfectly, stubbornly mediocre, and less a chore to sit through than either of 2017's Vin Diesel vehicles."[28]
Audience response[edit]
Several publications noted that while critics were harsh in their assessment of the film, viewers seemed to enjoy it more and gave positive reactions on social media.[29][30][31][32] Netflix announced that the film had been viewed more times in its first week than any of its other releases.[33] According to Nielsen ratings, about 11 million American viewers streamed Bright within the first three days of its release, with 56% of the audience being male and 7 million being between the ages of 18–49.[34] Netflix CEO Reed Hastings noted that: "The critics are pretty disconnected from the mass appeal...[they] are an important part of the artistic process but are pretty disconnected from the commercial prospects of a film. If people are watching this movie and loving it, that's the measurement of success."[35]
Soundtrack[edit]
Bright: The Album
Soundtrack album by Various artists
Released
December 15, 2017 (2017-12-15)
Genre
Hip Hop
pop
rock
Length
42:50
Label
Atlantic Records
WEA International
Producer
Alex da Kid
Dan Smith
Mark Crew
David Pramik
David Phelps
Grey
Louis Bell
Linus Wiklund
JMIKE
AC
Andrew Bolooki
Paul Judge
Marshmello
Viruss Beats
Steve Aoki
DJ Khalil
D. Sardy
Casey Bates
Charlie Andrew
Joe London
DRAM
Gabriel Niles
Zach Crowell
Singles from Bright: The Album
"World Gone Mad"
Released: November 21, 2017[36]
"Home"
Released: December 5, 2017[37]
The soundtrack, titled Bright: The Album, was released under Atlantic Records on December 15, 2017, just a week before the official release of the film on December 22, 2017.
Bright: The Album[38]
No.
Title
Writer(s)
Producer(s)
Length
1. "Broken People" (Logic and Rag'n'Bone Man)
Dan Priddy
Mark Crew
Alexander Grant
Rory Graham
Sir Robert Hall II
Nicholas Steele
David Pramik
Alex da Kid
3:32
2. "World Gone Mad" (Bastille)
Dan Smith
Smith
Mark Crew
3:16
3. "Home" (Machine Gun Kelly, X Ambassadors and Bebe Rexha)
Sam Nelson Harris
David Phelps
Robert Gillies
Richard Baker
Pramik
Jacob Hawkes
Charlie Snyder
David Pramik
Phelps
3:22
4. "Crown" (Camila Cabello and Grey)
Kyle Trewartha
Karla Cabello
Sarah Aarons
Michael Trewartha
Grey
Louis Bell
3:21
5. "Darkside" (Ty Dolla $ign and Future featuring Kiiara)
Jeremy Coleman
Linus Wiklund
Nayvadius Wilburn
Tyrone Griffin Jr.
Kiara Saulters
Jonnali Parmenius
Wiklund
JMIKE
AC
Andrew Bolooki
3:53
6. "Danger" (Migos and Marshmello)
Chris Comstock
Quavious Marshall
Kiari Cephus
Kirshnik Ball
Paul Judge
Judge
Marshmello
3:34
7. "That's My Nigga" (Meek Mill, YG and Snoop Dogg)
Shawn Carter
Andre Young
Melvin Bradford
Scott Storch
Robert Williams
Calvin Broadus Jr.
Eric Gamzoyan
Keenan Jackson
Viruss Beats
3:19
8. "Smoke My Dope" (Steve Aoki and Lil Uzi Vert)
Steven Aoki
Symere Woods
Bobby Turner
Kenneth Smith
Steve Aoki
3:22
9. "FTW (Fuck the World)" (A$AP Rocky and Tom Morello)
Thomas Morello
Khalil Abdul-Rahman
Rakim Mayers
DJ Khalil
2:23
10. "Cheer Up" (Portugal. The Man)
David Sardy
Casey Bates
John Gourley
D. Sardy
Bates
2:46
11. "Hares on the Mountain" (alt-J)
Traditional
Charlie Andrew
3:48
12. "Campfire" (DRAM and Neil Young)
Joe Spargur
Shelley Massenburg-Smith
Roget Chahayed
Gabriel Niles
Joe London
D.R.A.M.
Niles
3:40
13. "This Land Is Your Land" (Sam Hunt)
Woody Guthrie
Zach Crowell
2:34
Total length: 42:50
Charts[edit]
Chart (2017–18)
Peak
position
Australian Albums (ARIA)[39]
85
Canadian Albums (Billboard)[40]
13
Dutch Albums (MegaCharts)[41]
92
Finnish Albums (Suomen virallinen lista)[42]
18
German Albums (Offizielle Top 100)[43]
97
New Zealand Albums (RMNZ)[44]
24
US Billboard 200[45]
48
US Top R&B/Hip-Hop Albums (Billboard)[46]
28
Sequel[edit]
In December 2017, Netflix ordered a sequel.[47] The following month Netflix confirmed they were moving ahead with the sequel, with Smith and Edgerton reprising their roles and Ayer directing and writing the script.[33]
See also[edit]
Alien Nation
Cast a Deadly Spell
Shadowrun
Special Unit 2
Witch Hunt (1994 film)
Wishfart
References[edit]
Jump up ^ "Netflix is carrying $20 billion in debt. Can it keep borrowing its way to success?". Los Angeles Times. July 31, 2017.
^ Jump up to: a b Goldberg, Matt (March 2, 2016). "David Ayer to Direct Will Smith and Joel Edgerton in Fantastical Cop Flick 'Bright'". Collider. Retrieved February 20, 2017.
^ Jump up to: a b Kroll, Justin (March 3, 2016). "William Smith, David Ayer Reteaming on Max Landis Spec 'Bright'". Variety. Retrieved February 20, 2017.
Jump up ^ Khatchatourian, Maane (February 27, 2017). "Watch the First Teaser for Will Smith's Fantasy Cop Thriller 'Bright'". Variety. Retrieved March 3, 2017.
^ Jump up to: a b "Poor Will Smith! Critics tore apart Netflix's first hopeful blockbuster, 'Bright'". Mashable. December 22, 2017. Retrieved December 28, 2017.
Jump up ^ Goldberg, Matt (March 18, 2016). "Netflix Makes Mammoth Deal for David Ayer's 'Bright' Starring Will Smith". Collider.
Jump up ^ Ankers, Adele (May 19, 2016). "Noomi Rapace in Talks to Join Will Smith in David Ayer's Bright". Screen Rant.
Jump up ^ Trumbore, Dave (July 25, 2016). "Watch: Max Landis Hopes 'Bright' Will Be His 'Star Wars'". Collider.
Jump up ^ James, Daron (August 19, 2016). "Why DP Roman Vasyanov Chose Anamorphic & More Tales from Shooting 'Suicide Squad'". No Film School.
Jump up ^ Kit, Borys (October 11, 2016). "David Ayer's 'Bright' Lands 'Mr. Church' Actress Lucy Fry". The Hollywood Reporter.
Jump up ^ N'Duka, Amanda (October 17, 2016). "David Ayer-Helmed Thriller 'Bright' Adds Andrea Navedo; Austin Hébert Cast In 'Burden'". Deadline Hollywood.
Jump up ^ Kroll, Justin (October 18, 2016). "'Orange Is the New Black' Actor Brad William Henke Joins Will Smith in 'Bright'". Variety.
Jump up ^ Briers, Michael (October 2016). "David Ayer's Fantasy Cop Thriller Bright Adds Two". wegotthiscovered.com.
Jump up ^ Kit, Borys (November 9, 2016). "Edgar Ramirez Joins Will Smith in David Ayer's Fantasy Thriller 'Bright'". The Hollywood Reporter.
Jump up ^ N'Duka, Amanda (November 11, 2016). "Ashley Bell Cast As Lead In 'Next Door'; Alex Meraz Joins David Ayer's 'Bright'". Deadline Hollywood. Retrieved November 16, 2016.
Jump up ^ N'Duka, Amanda (November 15, 2016). "Matt Gerald Boards David Ayer's 'Bright'; Angel Bonanni Cast In 'Entebbe'". Deadline Hollywood. Retrieved November 16, 2016.
Jump up ^ Fleming Jr, Mike (November 16, 2016). "Ike Barinholtz Reunites With David Ayer, Will Smith On Netflix Film 'Bright". Deadline Hollywood. Retrieved November 16, 2016.
Jump up ^ N'Duka, Amanda (November 22, 2016). "Enrique Murciano Cast In Netflix's 'Bright'". Deadline Hollywood. Retrieved November 22, 2016.
Jump up ^ Caldwell, Kayla (November 7, 2016). "Joel Edgerton is unrecognizable in orc make-up as he joins Will Smith on set of new Netflix fantasy film Bright". Mail Online. Retrieved November 7, 2016.
Jump up ^ Evry, Max (November 9, 2016). "First Bright Set Photos Featuring Will Smith in Costume". ComingSoon.net. Retrieved November 9, 2016.
Jump up ^ Ayer, David (February 4, 2017). "That's a wrap on #BRIGHT. Even in the darkest times we can find the light". Twitter.
Jump up ^ "Bright (2017)". Rotten Tomatoes. Retrieved April 14, 2018.
Jump up ^ "Bright reviews". Metacritic. Retrieved December 27, 2017.
Jump up ^ Roeper, Richard (December 26, 2017). "Put an orc in it: Will Smith's cop fantasy 'Bright' a Netflix disaster". Chicago Sun Times. Retrieved December 22, 2017.
Jump up ^ Fear, David (December 21, 2017). "'Bright' Review: Will Smith's 'L.A.P.D. of the Rings' Is Just South of Dim". Rolling Stone. Retrieved December 28, 2017.
Jump up ^ Ehrlich, David (December 20, 2017). "'Bright' Review: Netflix's First Blockbuster Is the Worst Movie of 2017". IndieWire. Retrieved December 21, 2017.
Jump up ^ @DavidAyerMovies (December 21, 2017). "This is going on my fridge. Highest compliment is a strong reaction either way…" (Tweet) – via Twitter.
Jump up ^ Klimek, Chris (December 21, 2017). "Will Smith Plays Cops-And-Monsters In Unremarkable 'Bright". NPR. Retrieved December 28, 2017.
Jump up ^ "Audiences Seem To Love 'Bright' As Much As Critics Hate It". Decider. December 28, 2017. Retrieved January 1, 2018.
Jump up ^ "Netflix's 'Bright' lands 11 million audience, divides critics, viewers". Malay Mail. December 30, 2017. Retrieved January 1, 2018.
Jump up ^ "The Audience Seems To Like Bright A Whole Lot More Than The Critics Do". CinemaBlend. December 24, 2017. Retrieved January 1, 2018.
Jump up ^ "Critics be damned: 'worst film of the year' Bright is a huge hit for Netflix". The Telegraph. December 29, 2017. Retrieved January 1, 2018.
^ Jump up to: a b Mike Fleming, Jr. (January 3, 2018). "Netflix Firms 'Bright' Sequel With Will Smith". Deadline.com. Retrieved January 3, 2018.
Jump up ^ "Netflix's 'Bright' Lands 11 Million U.S. Streaming Viewers Over First Three Days". Decider.com. December 26, 2017. Retrieved January 1, 2018.
Jump up ^ https://variety.com/2018/film/news/netflix-execs-call-film-critics-disconnected-for-bashing-bright-film-1202672912/
Jump up ^ "Future Releases on Alternative Radio Stations". All Access. December 25, 2017. Archived from the original on November 20, 2017. Retrieved December 25, 2017.
Jump up ^ "Top 40/M Future Releases - Mainstream Hit Songs Being Released and Their Release Dates". All Access. December 25, 2017. Archived from the original on November 30, 2017. Retrieved December 25, 2017.
Jump up ^ "Bright: The Album by Various Artists on Apple Music". iTunes. Retrieved December 14, 2017.
Jump up ^ "ARIA Chart Watch #454". auspOp. January 6, 2018. Retrieved January 6, 2018.
Jump up ^ "Soundtrack Chart History (Canadian Albums)". Billboard. Retrieved January 17, 2018.
Jump up ^ "Dutchcharts.nl – Soundtrack – Bright: The Album" (in Dutch). Hung Medien. Retrieved January 6, 2018.
Jump up ^ "Eri esittäjiä: Bright: The Album" (in Finnish). Musiikkituottajat – IFPI Finland. Retrieved January 14, 2018.
Jump up ^ "Offiziellecharts.de – Soundtrack – Bright: The Album" (in German). GfK Entertainment Charts. Retrieved January 5, 2018.
Jump up ^ "NZ Top 40 Albums Chart". Recorded Music NZ. January 15, 2018. Retrieved January 12, 2018.
Jump up ^ "Soundtrack Chart History (Billboard 200)". Billboard. Retrieved January 9, 2018.
Jump up ^ "Soundtrack Chart History (Top R&B/Hip-Hop Albums)". Billboard. Retrieved December 28, 2017.
Jump up ^ "Netflix Has Already Ordered a 'Bright' Sequel with Will Smith Returning". Collider. December 20, 2017.
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Control self-assessment
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Control self-assessment is a technique developed in 1987 that is used by a range of organisations including corporations, charities and government departments, to assess the effectiveness of their risk management and control processes.
A "control process" is a check or process performed to reduce or eliminate the risk of error. Since its introduction the technique has been widely adopted in the United States, European Union and other countries. There are a number of ways a control self-assessment can be implemented but its key feature is that, in contrast to a traditional audit, the tests and checks are made by staff whose normal day-to-day responsibilities are within the business unit being assessed.[1] A self-assessment, by identifying the higher risk processes within the organisation, allows internal auditors to plan their work more effectively.[2] A number of governmental organisations require the use of control self-assessment. In the United States it is a requirement of the FFIEC that control self-assessments are performed on IT systems and operational processes on a regular basis.[3] Benefits claimed for control self-assessment include creating a clear line of accountability for controls, reducing the risk of fraud and the creation of an organisation with a lower risk profile.[4][5]
In certain circumstances control self-assessment is not always effective. For example, it can be difficult to implement in a decentralised environment, in organisations where there is high employee turnover, where the organisation goes through frequent change or where the senior management of the organisation does not foster a culture of open communication.[6]
Contents
1 Development and worldwide adoption
2 Performing the control self-assessment
3 Methodologies
4 Software tools
5 Benefits
6 Criticism
7 See also
8 External links
9 References
Development and worldwide adoption[edit]
Control self-assessment was developed by Gulf Canada in 1987 when the company's General Auditor, Bruce McCuaig was dissatisfied with the standard auditing techniques in use following the impact of the Watergate affair on the parent company, Gulf Oil Corporation. The decision to fully implement control self-assessment at Gulf Canada was driven by a number of factors. These included the presence of a consent decree requiring the company to report on its internal controls and the difficulties it was facing in estimating its oil and gas reserves using more traditional audit measures.[7]
Over the next ten years Gulf Canada developed a framework to support the analysis and evaluation of control processes by operational staff. This included anonymous voting to ensure there was no impediment to staff expressing their views. The approach was first published in Internal Auditor in December 1990.[8] Gulf Canada discontinued this facilitated meeting approach in 1997 although it continued with control self-assessment using different techniques.[7]
Following Gulf Canada's introduction of control self-assessment many private sector organisations implemented similar techniques. In the United States several states made reviews based on control self-assessment practices mandatory as did the Federal Deposit Insurance Corporation and the Canadian Deposit Insurance Corporation.[7]
Initially external auditors ignored the benefits of control self-assessment even though it was effective at providing audit evidence around the "soft" areas (such as staff morale) that are critical to the effectiveness of internal control systems.[9]
After a number of financial scandals, notably the collapse of Robert Maxwell's publishing empire, the United Kingdom government commissioned Adrian Cadbury to chair an investigation into corporate governance. The committee published its report The Financial Aspects of Corporate Governance in 1992. In section 4, Reporting and Controls, Cadbury made a number of recommendations that led to the increased adoption of control self-assessment in the UK. In particular section 4.5 of the Code of Practice contained within the report required that the directors of a company should report on the effectiveness of the company's system of internal control in each annual report.[10]
In March 2000 the European Commission approved a white paper on reform that led to a major change in the way the Commission was managed. These changes included recommendations for each department to establish an effective internal control system. To support the implementation of the internal controls the Directorate-General for Budget's Central Financial Service developed a control self-assessment process. This first control self-assessment identified several areas for improvement in internal control across the Commission most notably the need to implement a more systematic approach to risk management. The outcome of this first self-assessment was the implementation of the requirement for every Directorate General to perform a control and risk self-assessment annually.[11]
In 2007 the United States implemented the Sarbanes-Oxley Act. In order to comply with section 404 of the Act the company had to perform a top down risk assessment which necessitated the production of an "internal control report" that affirmed "the responsibility of management for establishing and maintaining an adequate internal control structure and procedures for financial reporting." 15 U.S.C. § 7262(a). This report has to include an evaluation of the effectiveness of the internal controls and procedures that are related to financial reporting. To meet this requirement organisations increasingly began to perform a control self-assessment using a recognised standard methodology. The organisation's external auditors, who are required to sign-off the internal control report, typically became more deeply involved in the control self-assessment process as it facilitated their later review of the internal control report.[12]
In the United Kingdom in 2011 the Financial Services Authority recognised in its recommendations for the improvement of operational risk management that the assessment of risks through a control self-assessment may be an important means of identifying risks. It also noted that for the assessment to be fully effective it had to be fully integrated into the financial organisation's risk-management process.[13]
Performing the control self-assessment[edit]
Section 1 of the control self-assessment form used by the Federal Transit Administration
The first step in control self-assessment is to document the organisation's control processes with the aim of identifying suitable ways of measuring or testing each control. The actual testing of the controls is performed by staff whose day-to-day role is within the area of the organisation that is being examined as they have the greatest knowledge of how the processes operate.[1][4] The two common techniques for performing the evaluations are:
Workshops, that may be but do not have to be independently facilitated, involving some or all staff from the business unit being tested;
Surveys or questionnaires completed independently by the staff.
Both approaches are the opposite of formal audits where the auditors, not the business unit staff, will perform the assessment.[1]
On completion of the assessment each control may be rated based on the responses received to determine the probability of its failure and the impact if a failure occurred. These ratings can be mapped to produce a heatmap showing potential areas of vulnerability.
Methodologies[edit]
A heatmap produced from the information captured in a control self-assessment. The cluster of issues in the red and amber sections of the heatmap indicate that this is a high risk area and probably in need of new or changed control processes.
Six basic methodologies for control self-assessment have been defined:[14]
Internal Control Questionnaire (ICQ) self-audit
Customised questionnaires
Control guides
Interview techniques
Control model workshops
Interactive workshops
The National Institute of Standards and Technology control self-assessment methodology is based on customised questionnaires. It is an IT focused methodology suitable for assessing system based controls. It provides a cost-effective technique to determine the status of information security controls, identify any weaknesses and, where necessary, define an improvement plan.[15] The methodology uses a questionnaire that contains specific control objectives and techniques against a system or group of systems can be tested and measured. The methodology was designed for United States federal agencies but can also be valuable for private sector organisations.[15]
The COBIT methodology can be used for control self-assessment; like the NIST methodology it was designed for IT focused assessments. COBIT's Process Description component provides a reference model of an organisation's processes and their ownership. Its Control Objectives component provides a set of requirements considered necessary for effective control of each IT process with the organisation. Assessment and evaluation of these components using the Management Guidelines component provides an assessment mechanism that generates a maturity model indicating if the organisation is meeting its control objectives.[14]
The Institute of Internal Auditors based its control self-assessment methodology on the Total Quality Management approaches of the 1990s as well as the COSO's framework. The methodology became part of the International Standards for Professional Practice of Internal Auditing and was adopted by a large number of major organisations.[16]
A number of other methodologies to standardise the control self-assessment have been published.[17][18] The Institute of Internal Auditors offers a certification in control self-assessment practice.[19]
Software tools[edit]
A number of software packages are available to support the control self-assessment process. These are typically modified versions of software developed originally for internal use by audit and accountancy firms such as Deloitte or by niche vendors specialising in business or financial management tools.
Benefits[edit]
Control self-assessment creates a clear line of accountability for controls, reduces the risk of fraud (by examining data that may flag unusual patterns of transactions) and results in an organisation with a lower risk profile.[4][5]
A number of other soft benefits have been claimed for organisations performing control self-assessment. These include a better understanding of business operations (by both management and operational staff); stronger awareness of risk practices; a reinforced corporate governance regime and internal audit efficiency improvements.[4][20]
Criticism[edit]
Some researchers have criticised control self-assessment as a flawed approach as the way risk is defined and measured is unsophisticated. In particular, control self-assessment may understate risk by not identifying extreme downside risk. An extreme downside risk is a highly improbable event that would have catastrophic consequences if it occurred. These risks should have a high overall risk score (generally calculated as a product of the probability of a risk occurring and the impact if it does occur on a scale of 1 to 5). Individuals performing the control self-assessment are consequently unable to significantly differentiate between risks leading to extreme low probability risks either being excluded from the analysis or grouped together with other more probable (but still unlikely) risks that have a less severe impact.[21]
The continual focus on risk elimination that a control self-assessment can lead to has also been criticised. The process of continual evaluation of risks and making plans to mitigate and eliminate them may lead to an unbalanced corporate culture where risks are eliminated ignoring the risk-return ratio of different business choices.[21]
See also[edit]
Internal audit
Internal control
External links[edit]
Control self-assessment tool used by the Federal Transit Administration
References[edit]
^ Jump up to: a b c Gilbert W. Joseph; Terry J. Engle (December 2005). "The Use of Control Self-Assessment by Independent Auditors". The CPA Journal. Retrieved 2012-03-10.
Jump up ^ "Control Self-assessment: An Introduction". The Institute of Internal Auditors. Retrieved 2012-03-10.
Jump up ^ "FFIEC IT Examination Handbook". FFIEC. Retrieved 2012-03-10.
^ Jump up to: a b c d McNally, J.Stephen (12 November 2007). "Control self-assessment:Everybody pitching in with internal controls". accountingweb.
^ Jump up to: a b Spencer Pickett, K.H. & Pickett, Jennifer M. (2010). The Internal Auditing Handbook (3rd ed.). John Wiley & Sons Ltd. p. 585.
Jump up ^ "Control Self-Assessment:The Future of Store Audits in Retail Stores" (PDF). Protivit Incorporated. 2006. Retrieved 2012-03-30.
^ Jump up to: a b c Professional Practice Pamphlet 98-2 A Perspective on Control Self-Assessment (PDF). Florida: The Institute of Internal Auditors. 1998. ISBN 089413406X. Retrieved 2012-03-31.
Jump up ^ K.H. Spencer Pickett (2011). The Essential Guide to Internal Auditing (Second ed.). John Wiley & Sons Limited. p. 81.
Jump up ^ Joseph, Gilbert W (1 August 2001). "Use of control self-assessment in audits". The CPA Journal. Retrieved 2012-03-12.
Jump up ^ Financial Aspects of Corporate Governance (PDF) (Report). 1 December 1992. ISBN 0852589131. Retrieved 2012-03-12.
Jump up ^ Central Financial Service, European Commission (18 March 2002). "2nd Quality Conference for Public Administration in the EU: Note for the File". Retrieved 2012-03-12.
Jump up ^ Engel, Terry J.; Joseph, Gilbert W. (2007). "Improving Internal and External Audit Coordination". 11 (2). CSA Sentinel. The Institute of Internal Auditors. Retrieved 2012-04-02.
Jump up ^ "Enhancing frameworks in the standardised approach to operational risk – Guidance note" (PDF). Financial Services Authority. January 2011. Retrieved 2012-03-11.
^ Jump up to: a b Sunil Bakshi (2004). "Control Self-assessment for Information and Related Technology". Journal of the Information Systems Audit and Control Association. 1: 4.
^ Jump up to: a b Marianne Swanson. "Security Self-assessment Guide for Information Technology Systems". National Institute of Standards and Technology. Retrieved 2012-04-04.
Jump up ^ Robert Moeller (2009). Brink's Modern Internal Auditing: A Common Body of Knowledge. John Wiley & Sons Inc., Canada.
Jump up ^ Álvarez, Gene (2004). Operational Risk: Practical Approaches to Implementation.
Jump up ^ Gene Álvarez; Phil Gledhill (24 November 2010). "A comprehensive risk and control self-assessment methodology". Risk.net. Retrieved 2012-03-10.
Jump up ^ "Certification in Control Self Assessment (CCSA)". Institute of Internal Auditors. Retrieved 2012-10-03.
Jump up ^ "Control Self Assessment". PriceWaterhouseCoopers. Retrieved 2012-03-10.
^ Jump up to: a b Lee, Judy; Wee, Lieng-Seng (28 September 2005). "Companies Using Control Self Assessment Don't Really Know their Risk" (PDF). Dragonfly. Retrieved 2012-03-14.
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Early 19th-century German ledger

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Tax accounting

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Accounting standards

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Management Accounting Principles

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Notes to the financial statements

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Risk elimination

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Internal Auditor

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Directorate General

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Sarbanes-Oxley Act

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Total Quality Management

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