AP BIOLOGY

CELL RESPIRATION

THE KREBS CYCLE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
The link reaction transfers which energy-rich organic molecule from the cytosol to the mitochondrion?
A
Pyruvate
B
Acetyl
C
NADH
D
ATP
E
CO2
Explanation: 

Detailed explanation-1: -Fatty acid biosynthesis occurs in the cytosol, so acetyl CoA has to be transported to the cytosol from the mitochondria. As it can not cross the membrane, it is transported out of mitochondria as citrate. Citrate is formed by the condensation of acetyl CoA with oxaloacetate by the enzyme citrate synthase.

Detailed explanation-2: -FADH2: High energy electron carrier used to transport electrons generated in Glycolysis and Krebs Cycle to the Electron Transport Chain. Glycolysis is the first of the three steps used to breakdown glucose to produce ATP.

Detailed explanation-3: -Acetyl-CoA must cross the mitochondrial membrane to the cytosol, where fatty acid synthesis takes place. Acetyl-CoA is combined with oxalacetic acid by the enzyme citrate synthase, creating citric acid.

Detailed explanation-4: -Adenosine 5’-triphosphate, or ATP, is the principal molecule for storing and transferring energy in cells. It is often referred to as the energy currency of the cell and can be compared to storing money in a bank.

There is 1 question to complete.