Blood glucose regulation

Question 1

What is blood glucose regulation controlled by?

Answer 1

the hormones insulin and glucagon

Question 2

What is blood glucose regulation an example of?

Answer 2

homeostasis and negative feedback

Question 3

Describe how the pancreas controls blood glucose levels if they rise too high

Answer 3

• pancreas detects rise in blood glucose concentration
• pancreas increases secretion of insulin and decreases secretion of glucagon
• insulin causes muscle and liver cells to remove glucose from the blood and store it as glycogen
• blood glucose concentration falls

Question 4

Describe how the pancreas controls blood glucose levels if they fall too low

Answer 4

• pancreas detects fall in blood glucose concentration
• pancreas decreases secretion of insulin and increases secretion of glucagon
• glucagon causes liver cells to convert glycogen into glucose and release it into the blood
• blood glucose concentration rises

Question 5

insulin

Answer 5

a hormone produced by the pancreas that regulates the level of sugar in the blood

allows glucose to enter cells
converts glucose to glycogen

Question 6

glycogen

Answer 6

glucose is converted to/stored as glycogen in liver and muscle tissues

Question 7

glucagon

Answer 7

changes glycogen into glucose

Question 8

Explain why blood glucose levels rise and then fall after a meal

Answer 8

After a meal the carbohydrates are being digested and absorbed into the blood as glucose
this causes the blood glucose concentration to increase

after a while insulin is secreted from the pancreas causing the conversion of glucose to glycogen
therefore the blood glucose concentration is falling

Question 9

Name the endocrine gland that secretes glucagon, and the target organ that the hormone affects.

Answer 9

pancreas, targets the liver

Question 10

the control of blood glucose concentration is an example of negative feedback
explain why

Answer 10

a change in blood glucose concentration causes mechanisms to act that bring about the opposite change
blood glucose concentration is therefore maintained within a small range

Question 11

insulin converts glucose to…

Answer 11

glycogen

Question 12

State how insulin allows glucose to enter cells

Answer 12

acts as a lock and key mechanism

glucose acts as the key

slots into a space in the cell which then allows glucose to pass into the cell

Question 13

How is insulin affected by type 1 and 2 diabetes?

Answer 13

in type 1 the pancreatic cells producing it are attacked by the immune system and damaged

in type 2 the cell receptors it binds to are damaged, stopping insulin from being able to let glucose enter cells