Question

The graph below represents the blood lactic acid concentration of an athlete during a race of 400m and shows a peak at point D

Answer 1

Answer:

Anaerobic Respiration

Explanation:

★ QUESTION :

Lactic acid production has occurred in the athlete while running in the 400m race. Which of the following processes explains this event ?

a) Aerobic respiration

b) Anaerobic respiration

c) Fermentation

d) Breathing

★ ANSWER :

Anaerobic Respiration

★ EXPLANATION :

Sometimes, when there is a lack of oxygen in our muscle cells, another pathway for the break-down of pyruvate is taken. Here the pyruvate is converted into lactic acid which is also a three-carbon molecule. This build-up of lactic acid in our muscles during sudden activity causes cramps.

This Anaerobic Respiration takes place in our muscle cells often when we do difficult works like running long distance , exercise a lot. You must have surely experienced it !

★ EQUATION OF ANAEROBIC RESPIRATION THAT TAKES PLACE IN OUR MUSCLE CELLS :

$\rm C_{6}H_{12}O_{6} \: { ( Glucose)\: (6 - carbon \: molecule)} \: \underset{ \rm{} }{\xrightarrow{\text{ In \: Cytoplasm }}} \: 2 \: \: C_{3}H_{4}O_{3} \: (Pyruvate)(3 - carbon \: molecule) \: \underset{ \rm{In \: our \: muscle \: cells} }{\xrightarrow{\text{ Lack \: of \: oxygen}}} \: \: C_ 3 H_ 6 O_ 3 \: (Lactic \: Acid) (3 - Carbon \: molecule) \: + \: Energy \: (2 \: ATP)$

Answer 2

This graph shows the anaerobic respiration in the muscle during a race. The D shows the high consumption of the oxygen by the muscle and forms the lactic acid and then it is reduced after the relaxation.

Explanation:

• There isn't enough oxygen to meet the ATP demands in the running race, and the muscle cells switch over to anaerobic respiration, which produces lactic acid.
• The lactic acid then builds up, causing decreased muscle contraction.
• The lactic acid needs to be oxidized to carbon dioxide and water later.
• Anaerobic respiration generates only two ATPs and produces lactic acid. Some of the lactic acids remain in the muscle fibers, where it contributes to muscle fatigue.
• During strenuous exercise, a lot of ATP needs to be produced.
• Lactic acid is removed from the muscles after the exercise through the oxidation process that converts the lactic acid into carbon dioxide and water in the inactive muscles and organs.