Question

Which one is not correct about the Krebs cycle?
A. It is also called the citric acid cycle.
B. The intermediate compound which links glycolysis with the Krebs cycle is malic acid.
C. It occurs in mitochondria.
D. It starts with six carbon compounds.

Answer 1

Hint:-Krebs cycle is a series of events in which two carbon dioxide, one ATP, and NADH are released. It starts with four carbon molecules. Krebs cycle involves a series of events including redox, dehydration, hydration, and decarboxylation reactions.

Complete step-by-step solution:-
Krebs cycle is also known as the citric acid cycle because this reaction starts with the six-carbon compound which is citric acid. It occurs in the mitochondrial matrix. Krebs cycle is a closed-loop cycle. And each loop of the cycle generates a molecule of ATP. This cycle consists of eight steps which include redox, dehydration, hydration, and decarboxylation reactions. It is an aerobic pathway because NADH is produced and the electrons released are used up in the next cycle which uses oxygen.
        The process of the cycle starts with the condensation of acetyl- CoA with oxaloacetate. This reaction is controlled by the amount of ATP present. If the ATP level increases then the rate of the reaction decreases and vice versa. After glycolysis, the pyruvate is then converted into acetyl CoA which enters the citric acid cycle. The Krebs cycle is the pathway that all organisms use to generate energy. The intermediate compound that links pyruvate to the Krebs cycle is Acetyl CoA. So, the answer is option (B) ‘the intermediate compound which links glycolysis with the Krebs cycle is malic acid’.

Note:-
Krebs cycle is necessary for producing an ATP molecule for the cell. Kreb cycle is a part of cellular respiration which starts from the glycolysis process and ends at an electron transport chain reaction. Regulation of the Krebs cycle depends on the supply of NAD+ and the utilization of ATP in the day-to-day activities of living organisms. It plays a vital role in gluconeogenesis, lipogenesis, and interconversion of amino acids