U3 Homeostasis: Blood glucose regulation

Question 1

What form does sugar in the blood take?

Answer 1

Glucose

Question 2

Why do cells need a constant supply of glucose?

Answer 2

Glucose is the source of energy for all cells’ activities

Energy is released from cellular respiration:
glucose + O2 → CO2 + H2O + energy

Question 3

Where does the body get glucose from?

Answer 3

Carbohydrates in our food being broken down into glucose during digestion then being absorbed into the blood through the walls of the small intestine

Question 4

What is glucose stored as?

Answer 4

Glycogen, a molecule made of long chains of glucose molecules

Question 5

Glycogenesis

Answer 5

The conversion of glucose into glycogen for storage when stimulated by insulin

Question 6

Gluconeogenesis

Answer 6

The conversion of fats or amino acids into glucose

Question 7

Glycogenolysis

Answer 7

The conversion of glycogen into glucose using glucagon

Question 8

Lipogenesis

Answer 8

The conversion of glucose into extra fats or proteins

Question 9

Lipolysis

Answer 9

The conversion of extra fats or proteins into glucose

Question 10

Beta cells and Alpha cells

Answer 10

Beta cells
- secrete insulin to decrease blood glucose level
- glycogenesis (glucose into glycogen)
- lipogenesis (glucose into fat)
- protein synthesis (glucose into protein)
- translocation (glucose transported into body cells)

Alpha cells
- secrete glucagon to increase blood glucose level
- glycogenolysis (glycogen into glucose)
- gluconeogenesis (fats into glucose)
- lipolysis (fats into glucose)

Question 11

Hepatic portal vein

Answer 11

• Where most of the liver’s blood supply travels through
• Brings blood directly from the stomach, spleen, pancreas and intestines
• Means the liver is the first gland that can absorb the nutrients from digested food

Question 12

Roles of adrenal glands in regulation of blood glucose level

Answer 12

Adrenal cortex
- Stimulate by secretion of adrenocorticotropic hormone (ACTH) from the anterior pituitary lobe

• Secretes glucocorticoids (eg: cortisol), which:
• regulate carbohydrate metabolism by ensuring enough energy is provided to the cells
• stimulate the conversion of glycogen into glucose during glycogenolysis

Adrenal medulla
- Secretes adrenaline noradrenaline, which:
- increase blood glucose level through glycogenolysis
- stimulate production of lactic acid (which can be converted into glucose in the liver) from glycogen in muscle cells