In the cyclic reaction sequence called the krebs cycle, which chemical event does not take place?
a.The acetyl group is joined with a four carbon molecule, oxaloacetate.
b. Two carbons per cycle are made into CO2 molecules.
c. Electrons generated are used to produce NADH.
d. Pyruvate molecules are restored to the cycle.
e. The resulting six carbon molecule is oxidized.
I know it's not a. but that's as far as I have gotten.
Any help would be greatly appreciated!
To determine which chemical event does not take place in the Krebs cycle, let's analyze each option.
a. The acetyl group is joined with a four carbon molecule, oxaloacetate.
This is a step in the Krebs cycle called the condensation of acetyl CoA with oxaloacetate to form citrate. So, this event does take place in the Krebs cycle.
b. Two carbons per cycle are made into CO2 molecules.
This is also a step in the Krebs cycle where carbon atoms are released as carbon dioxide (CO2) molecules. Each turn of the cycle releases two CO2 molecules. So, this event does take place in the Krebs cycle.
c. Electrons generated are used to produce NADH.
During the Krebs cycle, energy-rich electrons are released and captured by electron carriers like NAD+ (nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide) to form NADH and FADH2. So, this event does take place in the Krebs cycle.
d. Pyruvate molecules are restored to the cycle.
This statement is incorrect. The Krebs cycle does not directly involve pyruvate molecules being restored. Pyruvate molecules are the end products of glycolysis, a separate process that occurs before the Krebs cycle. However, pyruvate molecules are further converted into acetyl CoA, which is then used in the Krebs cycle. So, this event does not take place in the Krebs cycle.
e. The resulting six carbon molecule is oxidized.
During the Krebs cycle, the six carbon molecule citrate is gradually oxidized, resulting in the release of energy-rich electrons and the formation of NADH and FADH2. So, this event does take place in the Krebs cycle.
Based on the analysis, the chemical event that does not take place in the Krebs cycle is:
d. Pyruvate molecules are restored to the cycle.