The TCA cycle
A) begins with the formation of a molecule of citric acid.
B) directly produces most of the ATP from the catabolism of glucose.
C) does not form any carbon dioxide.
D) contains enzymes called cytochromes.
E) forms acetyl CoA from glucose.

Question

Quizplus · Accepted Answer

The TCA cycle begins with the formation of a molecule of citric acid (also known as citrate). This is the first step in the cycle, which ultimately generates energy in the form of ATP. The TCA cycle does not directly produce most of the ATP from the catabolism of glucose - this occurs through oxidative phosphorylation in the electron transport chain. The TCA cycle does form carbon dioxide as a byproduct, which is released into the atmosphere during cellular respiration. Cytochromes are not enzymes found in the TCA cycle, but rather in the electron transport chain. Finally, acetyl CoA is a molecule that is produced from the breakdown of glucose, and it enters the TCA cycle as the starting molecule (along with oxaloacetate) to form citrate.

The TCA Cycle