Question

Glucagon causes a. use of fat for energy. b. glycogen to be converted to glucose. c. use of amino acids to form fats. d. Both a and b are correct. e. None of these is correct.

Short answer

d. Both a and b are correct.

Step-by-step solution

a. Use of fat for energy

Glucagon is known to stimulate lipolysis, which is the breakdown of fat (triglycerides) into fatty acids and glycerol, providing energy to the body. Therefore, statement a is correct.

b. Glycogen to be converted to glucose

Glucagon causes the liver to convert stored glycogen into glucose, which is then released into the bloodstream to maintain blood glucose levels. This process is called glycogenolysis. Statement b is also correct.

c. Use of amino acids to form fats

This statement is not related to glucagon's primary functions. Glucagon indirectly influences amino acid metabolism, but it's not responsible for converting amino acids into fats. Statement c is incorrect.

d. Both a and b are correct.

Since statements a and b are both correct regarding the effects of glucagon, statement d is the correct answer.

e. None of these is correct.

As both a and b described accurate effects of glucagon, statement e is incorrect. In conclusion, the correct answer is:

Answer

d. Both a and b are correct.

Key concepts

Lipolysis

Lipolysis is the process by which triglycerides, the stored form of fat in the body, are broken down into fatty acids and glycerol. This process becomes particularly important during states of fasting or energy demand. At such times, the body's need for energy exceeds the supply of glucose, prompting the breakdown of fat stores.
Glucagon, a hormone produced by the pancreas, plays a crucial role in lipolysis. When blood sugar levels fall, glucagon is released, signaling fat cells to activate lipolysis. The resulting fatty acids can then be used as fuel by many tissues in the body, including muscles.
To sum up, lipolysis is vital for maintaining energy homeostasis. By providing an alternate energy source, it ensures that the body continues to function effectively when glucose levels are low.

Glycogenolysis

Glycogenolysis is the process through which glycogen, a stored form of glucose in the liver and muscles, is broken down into glucose. This glucose is then released into the bloodstream to stabilize blood sugar levels, especially during fasting or intense exercise.
Glucagon is a key hormone that triggers glycogenolysis in the liver. Upon the detection of lowered blood glucose levels, glucagon is secreted and acts on the liver cells to accelerate the conversion of glycogen to glucose. This process ensures that the body and brain have a continuous supply of glucose.
In essence, glycogenolysis helps in maintaining glucose availability, especially during periods of energy need, and is a critical part of glucose homeostasis.

Glucose metabolism

Glucose metabolism is a broad term that encompasses all the processes by which glucose is utilized in the body for energy and storage. It involves numerous pathways, including glycolysis, gluconeogenesis, and glycogenesis, each playing a distinct role in energy management.
Glucagon also influences glucose metabolism by promoting glycogenolysis and gluconeogenesis. Whereas glycogenolysis converts glycogen to glucose, gluconeogenesis is the formation of glucose from non-carbohydrate sources, ensuring that glucose remains available during prolonged fasting.

• Glycolysis: Converts glucose into pyruvate, generating ATP.
• Gluconeogenesis: Synthesizes glucose from compounds like lactate and amino acids.
• Glycogenesis: Stores excess glucose as glycogen in the liver and muscles.

Through these processes, glucose metabolism ensures that energy needs are met efficiently in changing physiological conditions.