Practice Exam III
The next exam will consist of 15 multiple-choice, TRUE FALSE questions, 10 written questions
and 2 written extra credit questions. Please note there are more questions than that here.
The next two questions require the following terms:
Oxidative reactions of the pentose phosphate pathway.
iii) Non-oxidative reactions of the pentose phosphate pathway
iv) The TCA cycle and oxidative phosphorylation.
In a cell that required a great deal of energy and fatty acid synthesis, which of the
pathways, i-v, would be active in addition to fatty acid synthesis?
i, ii, iv
b) i ii, iii, iv
i, iv, v
2.Which pathways, i or iii, would be active in rapidly dividing cells, like tumor cells, which
require nucleic acids for DNA synthesis?
Both i and iii
3.The committed step in the conversion of glucose-6-phosphate to ribose-5-phosphate is
catalyzed by glucose-6-phosphate dehydrogenase.
4. The cofactor thiamine pyrophosphate serves what purpose?
acyl transferase reactions, in which the TPP carbanion makes a nucleophilic
attack on the acyl group to be transferred
b) methylation and 1-carbon transfers
mutase reactions, in which the cobalt metal is reduced during radical formation
epimerization reactions in which the carbocation dissipates the negative charge
forming in the transition state.
5. During ATP synthesis, a proton gradient is used to protonate an aspartate residue in the c-ring
6. Glycogen is synthesized when:
insulin levels are low
b) glycogen phosphorylase is deactivated by dephosphorylation
in response to the global effectors, epinephrine and glucagon
None of the above
7. The oxidative portion of the pentose phosphate pathway produces 3, 4, 5, 6 and 7 carbon