CELL RESPIRATION
AEROBIC RESPIRATION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Acetyl-CoA
|
|
|
Citrate
|
|
|
Oxaloacetate
|
|
|
Malate
|
Detailed explanation-1: -Before the Krebs cycle begins, pyruvate, 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: -Pyruvate, derived from glycolysis, is firstly converted into acetyl-CoA (2-C) which is subsequently condensed with oxaloacetate (4-C) to form the 6-C compound citrate. This is cycled back to oxaloacetate via a series of reactions which form CO2 (as a waste product) as well as NADH and FADH.
Detailed explanation-3: -In the conversion of pyruvate to acetyl CoA, each pyruvate molecule loses one carbon atom with the release of carbon dioxide. During the breakdown of pyruvate, electrons are transferred to NAD+ to produce NADH, which will be used by the cell to produce ATP.
Detailed explanation-4: -In the presence of oxygen, pyruvate is transformed into an acetyl group attached to a carrier molecule of coenzyme A. The resulting acetyl CoA can enter several pathways, but most often, the acetyl group is delivered to the citric acid cycle for further catabolism.