Final answer:
The insulin/glucagon system regulates blood glucose levels by affecting glucose transport in tissues, inhibiting gluconeogenesis and promoting glycolysis and glycogen formation in the liver; glucagon has opposite effects, increasing glucose levels by stimulating glycogenolysis and gluconeogenesis. The correct answer is option b.
Step-by-step explanation:
The insulin/glucagon system significantly impacts several metabolic processes:
- Glucose transport: Insulin increases the amount of glucose transporter proteins in the cell membranes of tissues like muscles and the liver, facilitating the uptake of glucose from the blood into the cells for energy.
- Gluconeogenesis: This process of creating new glucose within the liver is inhibited by insulin, ensuring that blood glucose levels do not rise excessively after meals.
- Glycolysis: Insulin promotes this process, which breaks down glucose to produce ATP as an energy source for the body's cells.
- Glycogen formation: Excess glucose is stored as glycogen in the liver and muscles, and insulin promotes this storage mechanism.
On the other hand, glucagon works antagonistically to insulin; it raises blood glucose levels by promoting glycogenolysis (breaking down glycogen into glucose) and gluconeogenesis in the liver when glucose levels are low, such as between meals or during exercise.