Question

Explain the process of the breakdown of glucose by various pathways.

Answer 1

Glucose:

1. Glucose is the most important source of energy for all living things.
   
2. The food we eat is broken down into carbohydrates, the most important of which is glucose.
   
3. Glucose is oxidized to provide energy to the body.
4. The following are the various ways in which glucose is broken down.

Aerobic Respiration:

1. Aerobic respiration occurs only in the presence of oxygen.
   
2. In aerobic respiration, there are three specific processes, which are glycolysis, the Krebs cycle, and the electron transport chain (oxidative phosphorylation).
   
3. In this process, the glucose is converted to pyruvate during glycolysis and the same pyruvate produces carbon dioxide and water, along with the generation of energy.​

Anaerobic Respiration:

1. The anaerobic respiration process takes place in the absence of oxygen.
   
2. Two types of fermentation can occur in the absence of oxygen. ​

Alcoholic Fermentation:

1. Alcoholic fermentation occurs in yeast, where due to the absence of oxygen only glycolysis occurs and at the end of glycolysis the pyruvate is produced from glucose.
   
2. The pyruvate is converted to ethyl alcohol due to alcoholic fermentation. ​

Lactic acid Fermentation:

1. Lactic acid fermentation occurs in the system due to the lack of oxygen.
   
2. It occurs in the muscles where lactic acid is produced and accumulated in an anaerobic condition. ​