Advanced Dental Admission Test (ADAT)

What effect does insulin have on metabolic processes?

1. Inhibits glycogen formation

2. Stimulates glycogen formation and cellular glucose uptake

3. Activates gluconeogenesis

4. Stimulates lipolysis

The correct answer is: Stimulates glycogen formation and cellular glucose uptake

Insulin primarily plays a crucial role in regulating blood glucose levels and facilitating energy storage in the body. When insulin is released from the pancreas, it stimulates glycogen formation in the liver and muscle tissues. This process involves converting excess glucose into glycogen, which can be stored for future energy needs. Additionally, insulin promotes cellular glucose uptake by increasing the permeability of cell membranes to glucose, especially in muscle and adipose (fat) tissues. This dual effect not only lowers blood sugar levels but also ensures that energy is stored for use during periods of low glucose availability. The other options do not reflect insulin’s primary metabolic function. For example, inhibiting glycogen formation would lead to higher blood sugar levels rather than its regulation. Activating gluconeogenesis, the process of producing glucose from non-carbohydrate substances, occurs primarily during fasting or low-carbohydrate intake, which is contrary to the action of insulin. Similarly, stimulating lipolysis, the breakdown of fat stores into free fatty acids, is typically inhibited by insulin, as the hormone encourages fat storage rather than breakdown. Thus, the choice that accurately describes insulin's effect on metabolic processes is that it stimulates glycogen formation and cellular glucose uptake.