Blood Glucose

Question 0

How do hormones travel and where do they travel?

Answer 0

In the blood plasma, to target cells

Question 1

Where are hormones produced?

Answer 1

Endocrine glands

Question 2

Which hormones follow the second messenger model of action?

Answer 2

Adrenaline and Glucagon

Question 3

Describe the second messenger model of action (with the example: adrenaline)

Answer 3

• The hormone adrenaline approaches the receptor site
• Adrenaline fuses to the receptor site, and in doing so activates an enzyme inside the membrane
• The activated enzyme converts ATP to cyclic AMP, which acts as a second messenger that activates other enzymes that, in turn, convert glycogen to glucose

Question 4

What kind of gland is the pancreas?

Answer 4

BOTH endocrine and exocrine

Question 5

What is the pancreas’ exocrine function?

Answer 5

It secretes digestive enzymes into the pancreatic duct

Question 6

What is the pancreas’ endocrine function?

Answer 6

It secretes hormones (insulin and glucagon) directly into the blood

Question 7

Where are hormones secreted from in the pancreas?

Answer 7

Islets of Langerhans (cluster of cells)

Question 8

What do alpha cells manufacture and secrete?

Answer 8

Glucagon

Question 9

Which cells secrete glucagon?

Answer 9

Alpha cells

Question 10

Which hormone to beta cells manufacture and secrete?

Answer 10

Insulin

Question 11

What type of cells secrete insulin?

Answer 11

Beta cells

Question 12

What are the natural sources of blood glucose?

Answer 12

• Directly from the diet when carbohydrates are broken down

- Breakdown of glycogen (glycogenolysis)

Question 13

What is Gluconeogenesis?

Answer 13

The production of new glucose from sources other than carbohydrates

Question 14

What do beta cells detect?

Answer 14

A rise in blood glucose level

Question 15

What does insulin bind to?

Answer 15

Glycoprotein receptors on cell surface of most body cells

Question 16

What happens when insulin binds to the receptor? What does this result in?

Answer 16

• This modifies the tertiary structure of glucose carrier protein channels so that they allow more glucose into cells
• Activates enzymes that convert glucose to glycogen and fat

This results in:

• More glucose absorbed into cells
• increased respiration so more glucose is used up so more glucose is absorbed
• increased rate of conversion of glucose to glycogen (glycogenesis) in the liver and muscles
• increased conversion of glucose to fat

Question 17

What do alpha cells detect?

Answer 17

Low blood glucose

Question 18

When glucagon binds to receptors what happens?

Answer 18

• An enzyme is activated that converts glycogen to glucose

- There is an increase in the conversion of glycerol and amino acids into glucose (Gluconeogenesis)

Question 19

Where is adrenaline produced?

Answer 19

The Adrenal glands (above the kidneys)

Question 20

How does adrenaline raise blood glucose?

Answer 20

• Activates an enzyme that causes the breakdown of glycogen to glucose in the liver
• Inactivating an enzyme that synthesises glycogen from glucose