Since NAD+ and NADP+ are essentially equivalent in their tendency to attract ele
ID: 962099 • Letter: S
Question
Since NAD+ and NADP+ are essentially equivalent in their tendency to attract electrons, discuss how the two concentration ratios might be maintained inside cells at greatly differing values. Select all that apply.
a. Because NAD+-dependent enzymes usually act to dehydrogenate (oxidize) substrates, an [NAD+]/[NADH] ratio greater than unity tends to drive reactions in that direction.
b. [NADP+]/[NADPH] ratio less than unity provide concentrations that tend to drive these reactions in the direction of substrate oxidation.
c. Because NAD+-dependent enzymes usually act to hydrogenate (reduce) substrates, an [NAD+]/[NADH] ratio greater than unity tends to drive reactions in that direction.
d. [NADP+]/[NADPH] ratio less than unity provide concentrations that tend to drive these reactions in the direction of substrate reduction.
e. Because NADH-dependent enzymes usually act to hydrogenate (oxidize) substrates, an [NAD+]/[NADH] ratio greater than unity tends to drive reactions in that direction.
f. [NADP+]/[NADPH] ratio less than unity provide concentrations that tend to drive these reactions in the direction of enzyme oxidation.
Explanation / Answer
The ratio of NAD+ and NADH are essential in the cell for proper functioning. The concentrations are maintained inside the cells at different values,
a.
Because NAD++-dependent enzymes usually act to dehydrogenate (oxidize) substrates, an [NAD+]/[NADH] ratio greater than unity tends to drive reactions in that direction.
d.
[NADP+]/[NADPH] ratio less than unity provide concentrations that tend to drive these reactions in the direction of substrate reduction.