Question

If cells were undergoing glycolysis but could not carry out fermentation, what products would build up in the cytosol? Choose one:

a) NADH and pyruvate
b) ADP and CO2
c) NAD+ and ATP
d) H2O and citric acid

Answer 1

If cells were undergoing glycolysis but could not carry out fermentation, NADH and pyruvate would accumulate in the cytosol since fermentation is crucial for recycling NADH back into NAD+.

Step-by-step explanation:

If cells were undergoing glycolysis but could not carry out fermentation, the products that would build up in the cytosol are NADH and pyruvate. During glycolysis, glucose is broken down into pyruvate, generating a small amount of ATP and reducing NAD+ to NADH. Normally, fermentation would follow under anaerobic conditions, converting pyruvate into either ethanol or lactate, depending on the type of fermentation, thus recycling NADH back into NAD+. However, if fermentation does not occur, there is no mechanism for converting NADH back into NAD+, so both NADH and pyruvate accumulate. This inability to reform NAD+ halts glycolysis because it is required to oxidize glyceraldehyde 3-phosphate in one of the steps of glycolysis.