Question

During fatty acid mobilization, which of the following occur(s) HSL is activated. Free fatty acids are released. Gluconeogenesis proceeds in adipocytes. (A) I only (B) III only (C) I and II only (D) II and III only

Short answer

Option (C) I and II only.

Step-by-step solution

Understand Hormone-Sensitive Lipase (HSL) Activation

Hormone-sensitive lipase (HSL) is an enzyme that plays a key role in the mobilization of fatty acids from adipose tissue. During fatty acid mobilization, HSL is activated by hormones like epinephrine and glucagon.

Release of Free Fatty Acids

Once HSL is activated, it breaks down triglycerides into free fatty acids and glycerol, which are then released into the bloodstream. Thus, during fatty acid mobilization, free fatty acids are indeed released.

Analyze Gluconeogenesis in Adipocytes

Gluconeogenesis primarily occurs in the liver and kidneys, not in adipocytes (fat cells). Therefore, during fatty acid mobilization, gluconeogenesis does not proceed in adipocytes.

Evaluate the Given Options

Option I is correct because HSL is activated. Option II is correct because free fatty acids are released. Option III is incorrect because gluconeogenesis does not proceed in adipocytes. Therefore, the correct answer is (C) I and II only.

Key concepts

Hormone-Sensitive Lipase

Hormone-sensitive lipase (HSL) is an essential enzyme for breaking down stored fats, especially in adipose (fat) tissue. When your body needs energy, certain hormones like epinephrine and glucagon signal their presence. These hormones activate HSL.
Once activated, it starts breaking down triglycerides, which are fat molecules made up of glycerol and three fatty acids.
This action releases free fatty acids and glycerol into the bloodstream, allowing these components to be used as energy fuel.
Understanding HSL helps explain how the body accesses stored energy during times of need, especially between meals or during intense physical activity.
Remember that this process is essential for maintaining body energy balance, and without it, our body wouldn't efficiently release stored energy.

Free Fatty Acids

When Hormone-sensitive lipase (HSL) is activated, it emphasizes the significance of what happens next. HSL breaks down triglycerides into their components: glycerol and free fatty acids.
Free fatty acids are vital because they can be quickly used by muscles and other tissues for energy.
They travel through the bloodstream attached to a protein called albumin and reach various cells that need energy.
This process is crucial during periods when quick energy is needed, such as fasting, intense exercise, or stress.
Additionally, glycerol produced during this breakdown can be used by the liver for gluconeogenesis, creating glucose that can be released back into the blood to maintain blood sugar levels.
It's amazing to see how our body efficiently mobilizes stored fats to ensure a steady supply of energy in various situations.

Gluconeogenesis

Gluconeogenesis is a metabolic process that generates glucose from non-carbohydrate sources like glycerol, amino acids, and lactate. This process mostly occurs in the liver and kidneys, not in adipose (fat) tissue.
Gluconeogenesis is vital for maintaining blood glucose levels during fasting, intense exercise, or when dietary carbohydrates are low.
Interestingly, the glycerol released from triglycerides during fatty acid mobilization can be one of the substrates for gluconeogenesis.
However, it's key to understand that this activity primarily takes place in the liver and kidneys, ensuring glucose supply for the brain and red blood cells, which rely heavily on glucose.
This process underscores the body's intricate mechanisms to balance energy production and utilization.