BIO 351 MODULE 4 (2026/2027) QUESTIONS
AND CORRECT ANSWERS GRADED A+
What enzyme is involved in acetyl CoA formation in the mitochondria?
Pyruvate dehydrogenase complex (PDHC), responsible for "oxidative
decarboxylation"
What 5 cofactors does Pyruvate Dehydrogenase Complex require?
TPP, CoA-SH, lipoic acid, FAD/FADH2, NAD+/NADH, H+
What do each of the three enzymes in PDHC do?
E1 - Decarboxylates pyruvate
E2 - Acetyl CoA formation
E3 - Transfer of e- to NAD+ (forming NADH)
Where is ATP produced in the CAC?
Step 5 -> succinyl CoA to succinate
What was the cycle first evolved for?
Biosynthesis, e.g. transamination to form aspartate from oxaloacetate
, What other "fuels" feed into the CAC?
Proteins (amino acids) and fatty acids (every 2 Cs generates 1 acetyl CoA)
What is ketosis?
Increased fatty acid oxidation resulting in an abnormal increase in ketone bodies
(may be due to high levels of acetyl CoA which can react with itself)
What are conditions that cause ketosis?
Diabetes (greater fatty acid breakdown), fasting (increased gluconeo.), ketogenic
diet
What is chemiosmotic theory?
the concept that a proton concentration gradient serves as the energy reservoir that
drives ATP formation, free energy of e- transport is conserved
What four reactions are involved in the ETC?
1) NADH + H+ + 1/2 O2 -> NAD+ + H2O
2) 10 H+n -> 10 H+p (nonspon.)
3) 10 H+p -> 10 H+n (spon.)
4) xADP + xPi -> xATP + xH2O
AND CORRECT ANSWERS GRADED A+
What enzyme is involved in acetyl CoA formation in the mitochondria?
Pyruvate dehydrogenase complex (PDHC), responsible for "oxidative
decarboxylation"
What 5 cofactors does Pyruvate Dehydrogenase Complex require?
TPP, CoA-SH, lipoic acid, FAD/FADH2, NAD+/NADH, H+
What do each of the three enzymes in PDHC do?
E1 - Decarboxylates pyruvate
E2 - Acetyl CoA formation
E3 - Transfer of e- to NAD+ (forming NADH)
Where is ATP produced in the CAC?
Step 5 -> succinyl CoA to succinate
What was the cycle first evolved for?
Biosynthesis, e.g. transamination to form aspartate from oxaloacetate
, What other "fuels" feed into the CAC?
Proteins (amino acids) and fatty acids (every 2 Cs generates 1 acetyl CoA)
What is ketosis?
Increased fatty acid oxidation resulting in an abnormal increase in ketone bodies
(may be due to high levels of acetyl CoA which can react with itself)
What are conditions that cause ketosis?
Diabetes (greater fatty acid breakdown), fasting (increased gluconeo.), ketogenic
diet
What is chemiosmotic theory?
the concept that a proton concentration gradient serves as the energy reservoir that
drives ATP formation, free energy of e- transport is conserved
What four reactions are involved in the ETC?
1) NADH + H+ + 1/2 O2 -> NAD+ + H2O
2) 10 H+n -> 10 H+p (nonspon.)
3) 10 H+p -> 10 H+n (spon.)
4) xADP + xPi -> xATP + xH2O
