6.4.1 Homeostasis and negative feedback

Question 1

Homeostasis

Answer 1

Physiological control systems that maintain the internal environment within restricted limits

Question 2

Temperature

Answer 2

Temperature too high breaks hydrogen bonds, this changes the tertiary shape of the enzyme so the active site will be a different shape and no longer complementary to the substrate

Question 3

pH

Answer 3

If blood pH too high or low, enzymes become denatured because ionic and hydrogen bonds broken

Question 4

pH equation

Answer 4

pH = -log10(H+)

Question 5

Blood glucose concentration

Answer 5

If too high, water potential lowered and water moves out of cells by osmosis. If too low, not enough glucose for respiration

Question 6

Negative feedback

Answer 6

Normal levels, levels change from normal, receptors detect the change, communication via nervous or hormonal system, effectors respond

Question 7

Multiple negative feedback mechanisms

Answer 7

Having more than one negative feedback mechanism gives more control over changes

Question 8

Positive feedback

Answer 8

Amplifies a change away from the normal level, not present in homeostasis but helps rapidly activate processes in body