Homeostasis is the maintenance of a stable internal environment: Practice Questions

• a.Glycogenolysis
• b.Gluconeogenesis
• c.Glycolysis
• d.Glycogenesis

• a.Adrenaline acts as a transcription factor, moving into the nucleus to stimulate the expression of the glucagon gene.
• b.Adrenaline enters the liver cell and binds directly to an enzyme that converts glycogen into glucose.
• c.Adrenaline binds to a transmembrane receptor, activating adenylate cyclase to convert ATP into cAMP, which activates protein kinase.
• d.Adrenaline activates channel proteins in the cell membrane, allowing for the facilitated diffusion of glucose into the blood.

• a.To switch a biological process from a slow-acting hormonal control to a fast-acting nervous control.
• b.To amplify a stimulus to ensure a rapid and overwhelming physiological response.
• c.To restore a system to its original level or set point following a departure.
• d.To prevent any changes from ever occurring in the internal environment.

• a.It acts as a transcription factor that moves into the nucleus to stimulate glycogenesis.
• b.It directly hydrolyses glycogen into glucose-1-phosphate in the cytoplasm.
• c.It phosphorylates GLUT4 carrier proteins to increase the rate of facilitated diffusion of glucose.
• d.It converts ATP into cyclic AMP (cAMP), which then activates protein kinase.

• a.Passive diffusion of water out of the ascending limb increases the concentration of the urine.
• b.Antidiuretic hormone (ADH) increases the permeability of the ascending limb to water.
• c.The descending limb becomes permeable to sodium ions, allowing them to enter the filtrate by active transport.
• d.Active transport of sodium ions out of the ascending limb creates a low water potential in the interstitial space of the medulla.

Write your answer out first, then check it against the worked solution.

Write your answer out first, then check it against the worked solution.

Write your answer out first, then check it against the worked solution.