Question 1
Sometimes when we do heavy exercise, anaerobic respiration takes place in our muscle cells. What is produced during this process?
(a) Alcohol and lactic acid
(b) Alcohol and CO2
(c) Lactic acid and CO2
(d) Lactic acid only
The answer is (d).
While doing heavy exercise such as running, cycling, weightlifting, etc., we need high energy which creates an impermanent deficiency of oxygen in the muscle cells. In absence of oxygen, our body performs anaerobic respiration in which glucose present in the muscle cells is changed into lactic acid. This releases energy but in less amount.
Glucose → Lactic acid + Energy
Anaerobic respiration produces a relatively lesser amount of energy as compared to aerobic respiration, as glucose is not completely broken down in the absence of oxygen.