Question

The overall goal of glycolysis, Krebs cycle and the electron transport system is the formation of
(A) ATP in small stepwise reactions
(B) ATP in one large oxidation reduction
(C) Sugars
(D) Nucleic acid

Answer 1

Hint: To answer this question we have to know about the detailed steps of glycolysis, Krebs cycle and electron transport system. All these biochemical reactions help to generate ATP – the energy currency of the body.

Complete answer:In the glycolysis, the glucose is broken down into pyruvate and forms energy in the form of ATP. At the end of glycolysis, 2 ATP molecules are produced, or we can say the net gain of ATP is 2. This process takes place in cytoplasm.
In the oxidative decarboxylation of pyruvate, NADH+H+ is produced which helps in the production of 3 molecules of ATP.
In Krebs cycle, the Acetyl CoA that is formed in the oxidative decarboxylation step reacts with oxaloacetate to form citric acid – this leads to the beginning of Krebs cycle. The Krebs cycle produces 34 molecules of ATP and NADH. This biochemical reaction takes place in the matrix of mitochondria.
The NADH that is produced in the glycolysis, oxidative decarboxylation and Krebs cycle, enters the electron transport chain that takes place in the inner mitochondrial membrane and produces ATP by ATP synthase.
So, we can clearly see that the overall goal of glycolysis, Krebs cycle and the electron transport system is the formation of ATP by small stepwise reactions.

Hence, option A. ATP in small stepwise reactions is the correct answer.

Note: Remember the glycolysis, oxidative decarboxylation, Krebs cycle and electron transport chain pathways.
NADH helps to produce 3 molecules of ATP and FADH helps to produce 2 molecules of ATP.