- Ethanol is removed from the body primarily by:
exhaling
it from the lungs.
excreting
it in the urine.
metabolism
in the liver.
- In terms of carbohydrate metabolism, the most active organ
in the body is:
heart.
skeletal
muscle.
brain.
smooth
muscle.
- The standard free energy difference between NADPH and NADP+
is:
very
similar to
much
less than
much
greater than
that for NADH and NAD+?
- Lactose is synthesized in human mammary gland by lactose
synthetase. Uridine diphosphate galactose is joined to glucose
to form lactose. Can a mother homozygous for galactosemia (i.e.,
lacking uridyl transferase) produce lactose?
Yes
No
- Which is the best explanation for the observation of hypophosphatemia
(i.e., low blood phosphate) in a patient experiencing fructose
intolerance, i.e., lacking aldolase B?
Phosphate
would increasingly be tied up in fructose-1,6-bisphosphate.
Phosphate
would increasingly be tied up in fructose-1-phosphate.
Phosphate
would increasingly be tied up in dihydroxyacetone phosphate.
Phosphate
would increasingly be tied up in glyceraldehyde-3-phosphate.
- Which is the best explanation for the role of lactate dehydrogenase
in efficient anaerobic metabolism?
regenerate
pyruvate from lactate for pyruvate carboxylase activity
regenerate
pyruvate from lactate for pyruvate dehydrogenase activity
regenerate
NAD+ for alcohol dehydrogenase activity
regenerate
NAD+ for glyceraldehyde-3-phosphate dehydrogenase
activity
- What is the major regulatory step in glycolysis. How is this
reaction controlled?
Hexokinase
is inhibited at high [glucose].
Glucokinase
is inhibited at physiological [glucose-6-phosphate].
Pyruvate
carboxylase is activated by acetyl CoA.
Phosphofructokinase
1 is activated by AMP and inhibited by ATP and citrate.
- Consider the standard state free energies (DGo')
and free energies (DG) in a cell.
Are they different, and if so, why are they different?
Yes,
DGo' are at pH 1 and 25oC,
a nonphysiological condition.
Yes,
DGo' are at pH 7 and 37oC,
a physiological condition.
Yes,
DGo' are at 1 M concentration,
a nonphysiological condition.
No,
DGo' and DG
in a cell are the same.
- Which is the best explanation for drug induced erythrocyte
glucose-6-phosphate dehydrogenase deficiency?
Drug
metabolism and glutathione reduction requires NADPH.
Isomerization
of ribulose-5-phosphate to ribose-5-phosphate requires NADPH.
Glyceraldehyde-3-phosphate
dehydrogenase produces NADH.
Glyceraldehyde-3-phosphate
dehydrogenase produces NAD+.
- What is the biochemical importance of the following cofactors
and vitamins?
A. thiamine
B. lipoic acid
C. pantothenic acid
FAD
and FMN requiring enzymes (e.g. succinate dehydrogenase)
pyruvate
dehydrogenase
NAD
and NADP requiring enzymes (e.g. lactate dehydrogenase)
pyruvate
carboxylase