Question

Production of glucose from amino acids, fatty acids and glycerol is called
A. Glycogenesis
B. Gluconeogenesis
C. Glycogenolysis
D. Glycolysis

Answer 1

Hint:-When it comes to energy sources, glucose is the most prominent one. It is required by our cells and organs for performing the metabolic processes. Various food components can act as sources for glucose, but carbohydrates are the most common precursors. To answer this question, let us first understand the different processes given and then find out the correct answer.

Complete answer:
Step 1- Let us first understand the different processes given:
Glycogenesis- Glucose is stored in the liver and muscle cells of animals primarily in the form of a multi-branched polysaccharide called glycogen. The process of synthesis of glycogen from glucose is called glycogenesis and it occurs in circumstances when the glucose concentration in the blood is high enough to be shuttled to liver and muscle cells in the form of glycogen.
Gluconeogenesis- Though carbohydrates are the primary precursors of glucose, sometimes glucose is synthesized from non-carbohydrate sources such as amino acids, fatty acids and glycerol by a process called gluconeogenesis. Non- carbohydrate substrates are converted into pyruvates or other intermediates such as oxaloacetate which are then finally converted to glucose via gluconeogenesis pathway.
Glycogenolysis- The process of breakdown of glycogen to glucose so as to fulfill the immediate energy requirements is called glycogenolysis. It takes place in liver and muscle cells.
Glycolysis- A cascade of ten enzyme- dependent reactions occurring in the cytoplasm which converts one molecule of glucose into two molecules of pyruvate. Energy is released in the form of ATP AND NADH with a count of 4 and 2 respectively. It is a very significant pathway as glucose is required as a primary fuel source by the body tissues for normal metabolic functions.

Step 2: Thus, based on the above discussion, it is clear that the correct answer is (B)- Gluconeogenesis.


Note:-
Liver is the main site for gluconeogenesis. To some extent, the kidney also acts as the site for gluconeogenesis.
Though brain cells depend mainly on glucose for energy, it is the site where very little amount of gluconeogenesis takes place. Interestingly, gluconeogenesis in the kidney and liver serve to supply sufficient amounts of glucose in blood from where the brain cells (or muscle cells) take glucose for their metabolic requirements.
It is noteworthy to remember that gluconeogenesis and glycolysis are not a reversal of each other.