Since NAD+NAD+ and NADP+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. Match the items in the left column to the appropriate blanks in the sentences on the right. ResetHelp substrate reduction less greater reduce oxidize substrate oxidation enzyme reduction enzyme oxidation Because NAD+NAD+-dependent enzymes usually act to Because {\rm NAD}^+-dependent enzymes usually act to blank substrates, an [{\rm NAD}^+]/[{\rm NADH}] ratio blank than unity tends to drive reactions in that direction. substrates, an [NAD+]/[NADH][NAD+]/[NADH] ratio Because {\rm NAD}^+-dependent enzymes usually act to blank substrates, an [{\rm NAD}^+]/[{\rm NADH}] ratio blank than unity tends to drive reactions in that direction. than unity tends to drive reactions in that direction.