CELL RESPIRATION
THE KREBS CYCLE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Oxidized (reacts with oxygen to produce CO2)
|
|
|
Combined (reacts with oxygen to produce a larger molecule)
|
|
|
Decomposed
|
|
|
Burned
|
Detailed explanation-1: -Before the Krebs cycle begins, pyruvic acid, which has three carbon atoms, is split apart and combined with an enzyme known as CoA, which stands for coenzyme A. The product of this reaction is a two-carbon molecule called acetyl-CoA.
Detailed explanation-2: -The three-carbon pyruvic acid molecules are converted to a two-carbon molecule attached to Coenzyme A, called acetyl CoA, via the process of pyruvate oxidation. It is the product, acetyl CoA, which enters the Krebs cycle.
Detailed explanation-3: -The end product of glycolysis is pyruvate. 1 molecule of glucose produces 2 molecules of pyruvate. So 1 molecule of pyruvate is responsible for the release of 2 CO2 molecules during 1 Krebs cycle.
Detailed explanation-4: -Pyruvate oxidation steps More detailed diagram of the mechanism of pyruvate oxidation. A carboxyl group is removed from pyruvate and released as carbon dioxide. The two-carbon molecule from the first step is oxidized, and NAD+ accepts the electrons to form NADH.