Homeostasis - blood glucose

Question 1

What is homeostasis?

Answer 1

Homeostasis is the maintenance of an internal environment within restricted limits of an organism

Question 2

Importance of homeostasis

Answer 2

Enzymes are pH and Temperature specific

Changes to water potential = burst

Ability to adapt to a wider environment, greater survival rate

Question 3

5 features of a feedback mechanism (ORCEF)

Answer 3

Optimum point

Receptor

Coordinator

Effective

Feedback mechanism

Question 4

Negative feedback

Answer 4

Where a change reduces the effect of a change (blood glucose)

Question 5

Positive feedback

Answer 5

A deviation from an optimum causes even greater deviation from normal

Question 6

Ectotherms

Answer 6

Rely on outside sources to regulate body temperature

• Basking in sunlight
• Shelter
• Warmth from the ground

Question 7

Endortherms

Answer 7

Rely on inside sources to regulate body temperature

• vasoconstriction & vasodilation
• sweating
• shivering
• movement of hair

Question 8

Role of the pancreas in the control of blood glucose concentration

Answer 8

Made of cells that produce digestive enzymes known as Islets of Langerhans.

Question 9

Different types of cells of the islets of langerhans

Answer 9

Alpha cells = produce glucagon

Beta cells = produce insulin

Question 10

Role of the liver in regulating blood sugar

Answer 10

It is where insulin and glucagon take effect.

Question 11

Three processes that take place in the liver

Answer 11

Glycogenesis

Glycogenolysis

Gluconeogensis

Question 12

What is glycogenesis?

Answer 12

The conversion of glucose into glycogen

GENESIS = SYNTHESIS

Question 13

What is glycogenolysis?

Answer 13

The breakdown of glycogen to glucose

HYDROLYSIS = BREAKING DOWN

Question 14

What is gluconeogensis?

Answer 14

The production of glucose from other sources like amino acids and glycerol

Question 15

Factors effecting blood glucose concentration

Answer 15

Diet - glucose from carbohydrates

Glycogenolysis

Gluconeogensis

Question 16

Three hormones that regulate blood glucose

Answer 16

Insulin - beta cells

Glucagon - alpha cells

Adrenaline - adrenal gland

Question 17

How do beta cells regulate glucose concentration?

Answer 17

Beta cells have receptors that detect rises in blood glucose.

They respond by secreting insulin into the blood plasma

Insulin combines with glycoprotein receptors on all cells but RBC causing:

An increase in the rate of glucose absorption

Increase the respiratory rate of cells

Increase the rate of glycogenesis

Question 18

How do alpha cells regulate blood glucose concentration?

Answer 18

Fall in glucose detected by alpha cells

Glucagon is secreted directly into the blood plasma causing:

Attachment to protein receptors on liver cell

Activation of protein kinase

Active enzymes for gluconeogensis

Question 19

What is the tole of adrenaline in regulating blood glucose concentration?

Answer 19

Attach to receptors on the cell surface membrane and change the shape of the inner protein

Adenyl cyclase is activates which converts ATP to cAMP which binds to protein kinase and activates it

Protein kinase catalyses the reaction of glycogen to glucose which moves into the blood

Question 20

What is diabetes?

Answer 20

The inability to metabolise carbohydrate

Question 21

Two types of diabeties

Answer 21

Type 1

Type 2

Question 22

What is type 1 diabetes?

Answer 22

Due to the body being unable to produce insulin, autoimmune disorder where the B cells are destroyed.

Question 23

What is type 2 diabetes?

Answer 23

Glycoproteins are lost or unresponsive to insulin, caused by obesity and poor lifestyle choices

Question 24

How is type 1 diabetes controlled?

Answer 24

Controlled by insulin injections ONLY - biosensor used

Question 25

How is type 2 diabetes controlled?

Answer 25

Regulation of carbohydrate in diet OR insulin injections