Chapter 8, Problem 40A

Summary Introduction

To explain:

The reason for that muscle hurt for some time after a large amount of strenuous exercise.

Introduction:

Organisms obtain energy through a process called cellular respiration. This process occurs in two stages; glycolysis and aerobic respiration. Some cells can function for a short time when oxygen levels are low. In some cases, cells continue to produce energy through glycolysis. Fermentation occurs in cytoplasm and regenerates cell’s supply of NAD+ while producing a small amount of ATP.

Answer to Problem 40A

Skeletal muscles produce lactic acid when the body cannot supply enough oxygen during strenuous exercise. Due to the build- up of lactic acid in muscles, the muscles become fatigued and feel sore.

Explanation of Solution

The anaerobic pathway that follows glycolysis when there is insufficient supply of oxygen is called fermentation.

There are two types of fermentation; Lactic acid fermentation and Alcohol fermentation

Lactic acid fermentation- In this process, the enzymes convert the pyruvate made during glycolysis to lactic acid. Skeletal muscles produce lactic acid when the body cannot supply enough oxygen during strenuous exercise. The lactic acid builds up in the muscle cells due to which the muscles feel tired and hurt. They become sore and fatigued.