Chapter 8, Problem 37A

Summary Introduction

Introduction :

Glycolysis is first stage of cellular respiration that occurs in the cytoplasm of all the living cells. During glycolysis one 6 carbon glucose is converted into two molecules of 3 carbon pyruvic acid or pyruvate. Pyruvate is the molecule where most of the energy of glucose is stored at the end of glycolysis.

Answer to Problem 37A

Correct answer :

The correct answer is option (A) glycolysis.

Explanation of Solution

Explanation/justification for the correct answer :

Option (A) pyruvate. At the end of glycolysis two pyruvate molecules are formed. Most of the energy from the glucose is still contained in the pyruvate. In the presence of oxygen, pyruvate is transported into the mitochondrial matrix, where it is eventually converted to carbon dioxide. Thus, the correct answer is an option (A).

The explanation for the incorrect answer :

Option (B) acetyl CoA. Pyruvate is formed in the cytoplasm of the cell then it enters into the mitochondria matrix for further breakdown to acetyl CoA. Thus, this is an incorrect answer.

Option (C) ATP. It is energy currency which is produced at the end of cellular respiration. Thus, this is an incorrect option.

Option (D) NADH. NADH is reduced coenzyme which produced during glycolysis and Krebs cycle. It is oxidized through electron transport chain on the inner membrane of the mitochondria, where termination oxidation take place. It produces large amount of ATPs.  Thus, this is an incorrect answer.