5.18 Regulating Glucose

Question 1

What does our cells need glucose for?

Answer 1

Respiration

Question 2

How does glucose get into our blood?

Answer 2

Eating foods containing carbohydrates puts glucose into our blood from the small intestine. The carbohydrates would be broken down in the intestines into lots of glucose molecules. These would then be absorbed into the blood stream and cause your blood glucose concentration to increase.

Question 3

What body part are changes in blood glucose monitored by?

Answer 3

Pancreas

Question 4

Which two hormones are used to control the blood glucose?

Answer 4

Insulin and glucagon

Question 5

How is excess glucose stored in the liver and the muscles?

Answer 5

As glycogen

Question 6

How does insulin reduce blood glucose levels?

Answer 6

The rise in blood glucose concentration is detected by the pancreas (which is an organ that sits just behind the stomach) and in response it will release a hormone called insulin into the blood stream. As it is travelling around the body, the insulin will bind to receptors on certain cells which tells those cells to take in some of the glucose in the blood. This happens in many cells, but most important in liver and muscle cells; these two take up lots of the extra glucose molecules and combine them together to form glycogen (long term storage form of glucose). And because of the glucose being removed from the blood, the blood glucose levels decrease.

Question 7

How does glucagon increase blood glucose levels?

Answer 7

The pancreas would detect the low concentration of blood glucose and secrete glucagon into the bloodstream. As the glucagon travels around the body, it would bind to lots of different cells but mainly liver cells, which take the glycogen and break it down into lots of glucose molecules and then it would release these glucose molecules into the bloodstream. This would bring the blood glucose concentration levels back to normal so cells have a good supply of it for respiration.

Question 8

In what way do both insulin and glucagon work together?

Answer 8

In a negative feedback loop - antagonistically.

Question 9

What does ‘blood glucose levels’ or ‘blood glucose concentration’ refer to?

Answer 9

How much glucose is dissolved in our blood plasma

Question 10

What is a problem for when blood glucose levels fall too low?

Answer 10

There won’t be enough glucose for tissue cells to respire