Inhibitor Function P. FCCP 1. Inhibits cytochrome c oxidase Q. Cyanide 2. Makes the membrane permeable to protons R. Oligomycin A 3. Blocks mitochondrial uptake of succinate S. Butyl malonate 4. Inhibits ATP synthase
Mitochondrial Respiration Inhibitors: Function Matching
This question requires matching specific inhibitors of mitochondrial respiration with their corresponding functions. Let's analyze each inhibitor:
- P. FCCP: This chemical is a proton ionophore. It collapses the proton gradient across the inner mitochondrial membrane, making the membrane permeable to protons. This uncouples electron transport from ATP synthesis.
- Q. Cyanide: Cyanide is a potent inhibitor of Complex IV (cytochrome c oxidase) in the electron transport chain. It binds to the heme iron in the active site, preventing electron transfer to oxygen.
- R. Oligomycin A: Oligomycin A is known to inhibit ATP synthase (Complex V). It binds to the F0 subunit of ATP synthase, blocking proton flow through the enzyme and thus inhibiting ATP production.
- S. Butyl malonate: Butyl malonate is an inhibitor that competes with succinate for binding to the succinate dehydrogenase complex (Complex II). This effectively blocks the mitochondrial uptake or processing of succinate.
Matching Inhibitors to Functions
Based on the analysis:
- P (FCCP) matches with Function 2 (Makes the membrane permeable to protons).
- Q (Cyanide) matches with Function 1 (Inhibits cytochrome c oxidase).
- R (Oligomycin A) matches with Function 4 (Inhibits ATP synthase).
- S (Butyl malonate) matches with Function 3 (Blocks mitochondrial uptake of succinate).
Therefore, the correct matching is P-2, Q-1, R-4, S-3.
Important Questions from Photosynthesis Respiration and Electron Transport Chain
Which of the following are true with regard to anaerobic respiration in bacteria?
P. The final electron acceptor is an inorganic substance other than molecular oxygen
Q. The number of ATP molecules produced per glucose molecule is more than that produced in aerobic respiration
R. The number of ATP molecules produced per glucose molecule is less than that produced in aerobic respiration
S. Only substrate level phosphorylation is used to generate ATP
- ATP biosynthesis takes place utilizing the $H^+$ gradient in mitochondria and chloroplasts. Identify the correct sites of $H^+$ gradient formation.
Match the compounds in Group I with the correct entries in Group II.
Group I Group II P) Cyanide 1) K$^+$ ionophore Q) Antimycin A 2) Electron transfer from cytochrome b to cytochrome c$_1$ R) Valinomycin 3) F$_1$ subunit of ATP synthase S) Aurovertin 4) Cytochrome oxidase 5) Adenine nucleotide translocase - During photorespiration under low $CO_2$ and high $O_2$ levels, $O_2$ reacts with ribulose 1,5- bisphosphate to yield
Match items in Group I with Group II.
Group I Group II
P. Glycolytic pathway 1. Chloroplast
Q. Eukaryotic oxidative metabolism 2. Glyoxysomes
R. Glyoxylate cycle 3. Mitochondria
S. Calvin cycle 4. Cytosol
