Question

1. Oxygen atoms present in CO2 that is released in the Kreb's cyclecome from-

a. Molecular oxygen (O2)
b. Acetyl CoA
c. H2O
d. Acetyl CoA and H2O
e. NADH + H+

2. How many ATP are obtained by substrate-level phosphorylationduring a complete oxidation of a single glucose molecule (includeGlycolysis, PDH reaction and the Krebs' cycle, do NOT subtract"energy investment")

a. 1
b. 2
c. 4
d. 6
e. 32

3. One of the differences between the isocitrate dehydrogenasereaction and the alpha-ketoglutarate dehydrogenase reactionis:

a. only one of them is an oxidative decarboxylation reaction
b. only one of them uses CoA-SH as the source for one electron(hydrogen)
c. only one of them uses NAD+ as the electron (hydrogen)carrier
d. only one of them requires ATP
e. only one of them yields ATP (or GTP)

4. Which of the following would most likely act as an inhibitor ofthe enzymes of the citric acid cycle?

a. high concentration of ADP
b. high concentration of ATP
c. high concentration of NADH
d. high concentration of NAD+
e. more than one of the above