Question

Pyruvate can be converted into many other molecules by various biosynthetic and

metabolic pathways, which makes it a central hub in the regulation of cellular
metabolism. Which of the following molecules is not made from pyruvate?_____
(a) oxaloacetate
(b) ethanol
(c) lactate
(d) NADH

Answer 1

NADH is not made from pyruvate; instead, pyruvate conversion results in the production of NADH by transferring electrons to NAD+ during the formation of acetyl CoA.

Step-by-step explanation:

The molecule that is not made from pyruvate is NADH. During the process of glycolysis, pyruvate is created in the cytoplasm and then enters the mitochondria where it undergoes a transformation. Pyruvate is converted by the enzyme pyruvate dehydrogenase into a two-carbon acetyl coenzyme A (acetyl CoA) molecule during an oxidative decarboxylation reaction.

This process releases carbon dioxide and results in the transfer of electrons to NAD+ to form NADH. While pyruvate is central to metabolic pathways, leading to the synthesis of molecules such as oxaloacetate, ethanol, and lactate, NADH is not synthesized from pyruvate; instead, it is a recipient of electrons during the conversion of pyruvate to acetyl CoA.