How is the regulation of Complex IV in mitochondria adapted for hypoxic conditions?
Explanation
Under low oxygen (hypoxic) conditions, the transcription factor HIF-1 mediates an adaptive change in Complex IV. It promotes the replacement of the COX4-1 subunit with the COX4-2 isoform, which optimizes the enzyme's function for the lower oxygen concentrations, helping to reduce the formation of reactive oxygen species.
Other questions
According to the chemiosmotic theory as proposed by Peter Mitchell, what is considered the reservoir for energy extracted from biological oxidation reactions in mitochondria and chloroplasts?
Which component of the mitochondrial respiratory chain is described as a lipid-soluble benzoquinone with a long isoprenoid side chain, capable of shuttling reducing equivalents between less mobile electron carriers?
What is the function of Complex IV, also known as cytochrome oxidase, in the mitochondrial respiratory chain?
For each pair of electrons transferred from NADH through the respiratory chain to oxygen, how many protons are pumped out of the matrix by Complex I, Complex III, and Complex IV respectively?
What is the standard free-energy change (DG'°) for the transfer of a pair of electrons from NADH to O2, given that the standard reduction potential (E'°) for the NAD+/NADH pair is -0.320 V and for the O2/H2O pair is 0.816 V?
The binding-change model for ATP synthase proposed by Paul Boyer describes a rotational catalysis mechanism. What is the direct driver of the conformational changes in the beta subunits of the F1 complex?
What is the function of thermogenin, also known as uncoupling protein 1 (UCP1), found in the mitochondria of brown adipose tissue?
What is the role of cytochrome c in the process of apoptosis?
According to the endosymbiotic hypothesis, how did primitive eukaryotes acquire the ability to carry out oxidative phosphorylation?
What is the key distinction between the light-dependent reactions and the carbon-assimilation reactions in photosynthesis?
What is the energy, in kilojoules per einstein, of photons with a wavelength of 700 nanometers, as calculated in the worked example?
In the photochemical reaction center of purple bacteria, what is the 'special pair' designated (Chl)2 that is the site of the initial photochemistry?
In the Z scheme of photosynthesis in plants, what is the role of Photosystem II (PSII)?
What is the function of the oxygen-evolving complex, also known as the water-splitting complex, in photosynthesis?
How many protons are moved from the stroma to the thylakoid lumen for every four electrons passed from water to NADP+ in plant chloroplasts?
The inhibitor IF1 prevents ATP hydrolysis during hypoxia. Under what condition is IF1 inhibitory?
Which genetic disease is caused by a mutation in a mitochondrial gene for a subunit of Complex I, leading to bilateral loss of vision in early adulthood?
What is the primary function of accessory pigments like carotenoids in photosynthesis?
How many protons must flow inward through the F-type ATPase in yeast mitochondria to drive the synthesis of one molecule of ATP, including the transport of substrates?
What is the primary function of the glycerol 3-phosphate shuttle, which is active in skeletal muscle and brain?
What is the immediate electron donor that replaces the electron lost from P700 in Photosystem I after photoexcitation?
What is the key difference in the products of noncyclic versus cyclic electron flow in photophosphorylation?
What is the function of the enzyme superoxide dismutase in cells?
How many subunits of Complex IV (cytochrome oxidase) in the human mitochondrial respiratory chain are encoded by mitochondrial DNA?
In the Hill reaction, what did Robert Hill's experiments demonstrate about photosynthesis in isolated chloroplasts?
What is the primary role of the hypoxia-inducible factor (HIF-1)?
On the basis of the binding-change model, what are the three successive conformations that each catalytic beta subunit of ATP synthase cycles through?
What is the P/O ratio, defined as the ratio of ATP synthesized per 1/2 O2 reduced, when electrons enter the respiratory chain from succinate?
What is the effect of the drug rotenone on mitochondrial respiration?
In the process of state transitions in chloroplasts, what triggers the phosphorylation of LHCII and its move from association with PSII to PSI?
What is the primary function of the cytochrome P-450 enzymes located in the endoplasmic reticulum of hepatocytes?
In the absence of a proton gradient, what is the key observation about the reaction ADP + Pi <-> ATP + H2O on the surface of the F1 component of ATP synthase?
Heteroplasmy in mitochondrial genetics refers to which condition?
What is the role of the Pi-triose phosphate antiporter in the inner chloroplast membrane?
What is the total number of subunits in the F1 portion of mitochondrial ATP synthase?
Which of the following agents acts as an uncoupler of oxidative phosphorylation by functioning as a K+ ionophore?
What is the primary role of bacteriorhodopsin in Halobacterium salinarum?
What is the estimated free-energy change for moving one mole of protons down the electrochemical gradient in actively respiring mitochondria, given a measured change in electrical potential of 0.15 V and a pH difference of 0.75 units?
In the context of photorespiration, what is the oxygenase activity of rubisco?
Which of these complexes is NOT involved in the cyclic electron flow pathway in plant chloroplasts?
What is the primary factor that regulates the partitioning of glucose 6-phosphate between glycolysis and the pentose phosphate pathway in plants?
What is the role of the adenine nucleotide translocase in mitochondrial function?
How does the uncoupler 2,4-dinitrophenol (DNP) disrupt the tight coupling between electron transfer and ATP synthesis?
What is the predicted ATP yield per pair of electrons from FADH2 if the mitochondrial ATP synthase has 10 c subunits, as in yeast?
How many protein subunits does the enzyme Complex II (succinate dehydrogenase) contain?
Which class of cytochromes contains a heme group that is covalently attached to the protein through thioether bonds to two Cys residues?
What is the acceptor control of respiration?
In the Rieske iron-sulfur proteins, what is the unique feature of the iron atom's coordination?
What is the function of the enzyme ferredoxin:NADP+ oxidoreductase in plant photosynthesis?