Question

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Metabolism and Cellular Respiration Refer to Figure below as a guide to answer the folloaing questions Acetyt CoA Oxaloacetic acid CoA NADH Citric acid NAD Isocitric acid Malic acid Fumaric acid NAD co NADH -FADH FAD+ a-Ketoglutaric acid Succinic acid CO2NAD ATP Succinyl CoA ADP P NADH Figure above. Starting with citric acid and ending with oxaloacetic acid, how many ATP 6) Refer to molecules can be formed from oxidative phosphorylation? C) 15 D)11 A) 38 B) 1 E)5 7) The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is A) oxidation of glucose to CO2 and water. B) the difference in H+ concentrations on opposite sides of the inner mitochondrial membrane. C) the thermodynamically favorable flow of electrons from NADH to the mitochondrial electron transport carriers. D) The thermodynamically favorable transfer of phosphate from glycolysis and the Krebs cycle intermediate molecules of ADP. E) The final transfer of electrons to oxygen. most electrons follow which pathway? 8) Inside an active mitochondrion, A) pyruvate Krebs cycle ATPNADHoxygen B) glycolysisNADHoxidative phosphorylation ATPoxygen C) electron transport chain Krebs cycle ATP electron transport chain oxygen D) Krebs cycle E) Krebs cycle NADH FADH2 electron transport chain ATP 3

Answer 1

Answer 6: If we start from the citric acid and end at oxaloacetic acid,
NADH produced=3
FADH produced=1
In oxidative phosphorylation, an NADH can produce 3 ATPs and FADH can produce 2 ATPs.
So total ATP produced will be (3 x 3) + (1 x 2) = 11

Answer 7: Option B
The ATPase pump that combines ADP and iP into ATP can be considered as a rotating motor.
When 2 H+ ions pass through the pump across the membrane, a molecule of ATP is produced.
H+ ions flow across the membrane is driven by the chemical gradient i.e the concentration difference across the mitochondrial membrane.

Answer 8: Option D
ATP has no role in the electron transport cascade. The NADH and FADH produced in glycolysis and Kreb's cycle act as electron carriers and through the electron transport chain transfer the electrons to the final acceptor i.e Oxygen. Oxygen is reduced to water in this way.
Krebs Cycle-NADH-Electron Transport Chain-Oxygen