Problem 88 - Objective Biology for NEET

Question

Following are the functions of insulin except (a) Glycogenesis (b) \(\uparrow\) Glucose utilization by hepatocyte (c) \(\uparrow\) Glucose utilization by adipocyte (d) Gluconeogenesis

Step-by-Step Solution

Answer

Gluconeogenesis, option (d), is not a function of insulin.

Step 1: Understand Function (a) Glycogenesis

Glycogenesis is the process by which glucose is converted into glycogen. This process is stimulated by insulin. Hence, (a) is a function of insulin.

Step 2: Grasp Function (b) Glucose Utilization by Hepatocyte

A hepatocyte is a cell of the main tissue in the liver. Insulin increases the utilization of glucose by the hepatocytes. Therefore, (b) is a function of insulin.

Step 3: Identify Function (c) Glucose Utilization by adipocyte

Adipocytes are cells that store fat. Insulin plays a role in increasing the utilization of glucose by adipocytes. Hence, (c) is a function of insulin.

Step 4: Analyze Function (d) Gluconeogenesis

Gluconeogenesis is the process of creating glucose from non-carbohydrate sources. Insulin typically acts to lower glucose levels in the body by other processes but not by gluconeogenesis. Hence, (d) is not a function of insulin.

Key Concepts

Glycogenesis

Glycogenesis is a fascinating process where the body converts excess glucose into glycogen, a stored form of energy. This conversion is essential because it allows the body to store energy for later use, especially when blood glucose levels are back to normal or slightly low. This process mainly occurs in the liver and muscle tissues.

• During glycogenesis, insulin plays a crucial role by signaling the liver and muscle cells to absorb glucose from the blood and convert it into glycogen.
• Without insulin, this process would be inefficient, leading to excess glucose in the bloodstream, which is not healthy.

Thus, insulin ensures that your body maintains a balance and keeps energy readily available for times when it is needed.

Glucose Utilization

Glucose utilization is how the body's cells use glucose to produce energy. This process is vital because glucose serves as the primary fuel for most cells. Insulin significantly influences glucose utilization by facilitating its uptake into cells, particularly:

• Hepatocytes (liver cells): Insulin increases the glucose uptake by liver cells, encouraging them to use glucose for energy or convert it into storage forms like glycogen.


• Adipocytes (fat cells): Similarly, insulin enhances glucose uptake by adipose cells, promoting its conversion into fats for long-term energy storage.

This ensures that the body efficiently uses glucose and keeps blood sugar levels stable. When insulin functions properly, it keeps your energy levels high without causing an imbalance in blood sugar conditions.

Gluconeogenesis

Gluconeogenesis is a process where the body produces glucose from non-carbohydrate sources like amino acids and glycerol. It typically happens when the body is low on carbohydrates, such as during fasting or intense prolonged exercise. Unlike processes stimulated by insulin, gluconeogenesis is primarily controlled by other hormones like glucagon.

• In contrast to insulin's role in lowering glucose levels, gluconeogenesis increases glucose availability for energy.
• This process is crucial when your diet is low on carbohydrates or your body requires additional glucose during intense physical activity.

Therefore, gluconeogenesis acts as a backup to ensure that the body has a steady supply of glucose, even when normal intake is not available.