UBC BIOL 201- INTRO TO BIOCHEMISTRY EXAMS QUESTIONS AND
ACCUARATE ANSWERS 2024/2025 | VERIFIED
Complex I e- donor - NADH- donates 1H+ and 2e- in matrix (P:O ratio 2.5:1)
Complex IIa e- donor - Succinate donates 2H+ and 2e- in matrix (P:O ratio 1.5:1)
Complex IIb e- donor - L-3-P (glycerol-3-phosphate) donates 2H+ and 2e- in IMS (P:O ratio 1.5:1)
Coenzyme Q (CoQ) - Only lipid component of ETC (diffuses within membrane), donates/accepts
2H+ and 2e-. Collects e- from Complexes I, IIa, IIb and transfers to III.
Cytochrome C (C) - Accepts 2e- from Complex III, donates to IV. Diffuses along exterior surface
IMM.
H+ transport out of matrix - Complex I (4H+) and IV (2H+)
Consumption of H+ in matrix - Complex I (1H+) when FMN is reduced
Complex IV (2H+) when 1/2O2 is reduced
Complex III (2H+) when CoQ reduces Complex III
F0 baseplate - Embeds ATPase in IMM, contains transmembrane H+ channel
F1 head - Contains 3 active sites (Open, Loose, Tight) at which H+ can bind, rotates 360º for 9H+
that pass through, 3 ATP generated per full rotation
Amytal - ETC inhibitor, binds to complex I, blocks e- transfer to CoQ
Rotenone - ETC inhibitor, binds to complex I in fish and insects to block e- transfer to CoQ
, Antimycin-A - ETC inhibitor, blocks e- transport from complex III to C
Cyanide (CN-) and CO - bind to complex IV to block e- transfer to O2
DNP - H+ gradient inhibitor (uncoupler), can carry H+ through membrane to dissipate H+ gradient
Oligomycin - ATPase inhibitor by blocking H+ from passing through
e- transfer in CETC - H2O primary e- donor
NADPH terminal e- acceptor
-NADP+ reduced by 2e- and 1H+
NADPH vs NADH - NADPH required for anabolic rxns as reducing agent
NADH required for catabolic rxns as oxidizing agent
Substrate-Level Phosphorylation - rxn to synthesize ATP by direct phosphorylation through 1.
redox rxn to make high-energy intermediate 2. phosphorylation of ADP
Hydrolase - cleaves molecule by transferring part of it to H2O
Oxidoreductase - catalyzes redox rxns
Dehydrogenase - type of oxidoreductase, catalyzes any rxn involving NADH
Isomerase - intramolecular rearrangement
Transferase - transfer of groups between molecules
ACCUARATE ANSWERS 2024/2025 | VERIFIED
Complex I e- donor - NADH- donates 1H+ and 2e- in matrix (P:O ratio 2.5:1)
Complex IIa e- donor - Succinate donates 2H+ and 2e- in matrix (P:O ratio 1.5:1)
Complex IIb e- donor - L-3-P (glycerol-3-phosphate) donates 2H+ and 2e- in IMS (P:O ratio 1.5:1)
Coenzyme Q (CoQ) - Only lipid component of ETC (diffuses within membrane), donates/accepts
2H+ and 2e-. Collects e- from Complexes I, IIa, IIb and transfers to III.
Cytochrome C (C) - Accepts 2e- from Complex III, donates to IV. Diffuses along exterior surface
IMM.
H+ transport out of matrix - Complex I (4H+) and IV (2H+)
Consumption of H+ in matrix - Complex I (1H+) when FMN is reduced
Complex IV (2H+) when 1/2O2 is reduced
Complex III (2H+) when CoQ reduces Complex III
F0 baseplate - Embeds ATPase in IMM, contains transmembrane H+ channel
F1 head - Contains 3 active sites (Open, Loose, Tight) at which H+ can bind, rotates 360º for 9H+
that pass through, 3 ATP generated per full rotation
Amytal - ETC inhibitor, binds to complex I, blocks e- transfer to CoQ
Rotenone - ETC inhibitor, binds to complex I in fish and insects to block e- transfer to CoQ
, Antimycin-A - ETC inhibitor, blocks e- transport from complex III to C
Cyanide (CN-) and CO - bind to complex IV to block e- transfer to O2
DNP - H+ gradient inhibitor (uncoupler), can carry H+ through membrane to dissipate H+ gradient
Oligomycin - ATPase inhibitor by blocking H+ from passing through
e- transfer in CETC - H2O primary e- donor
NADPH terminal e- acceptor
-NADP+ reduced by 2e- and 1H+
NADPH vs NADH - NADPH required for anabolic rxns as reducing agent
NADH required for catabolic rxns as oxidizing agent
Substrate-Level Phosphorylation - rxn to synthesize ATP by direct phosphorylation through 1.
redox rxn to make high-energy intermediate 2. phosphorylation of ADP
Hydrolase - cleaves molecule by transferring part of it to H2O
Oxidoreductase - catalyzes redox rxns
Dehydrogenase - type of oxidoreductase, catalyzes any rxn involving NADH
Isomerase - intramolecular rearrangement
Transferase - transfer of groups between molecules
