1. homeostasis basics

Question 1

importance of maintaining temperature

Answer 1

(enzymes control rate of metabolic reactions)

1. TOO HIGH enzymes denature.
   vibrate too much = breaks H bonds that hold them in 3D shape.
   active site changes shape no longer works as a catalyst. metabolic reactions less efficient
2. TOO LOW enzyme activity reduced slowing rate of metabolic reactions
3. highest rate happens at optimum (about 37)

Question 2

importance of maintaining PH

Answer 2

(enzymes control rate of metabolic reactions)

1. TOO HIGH or TOO LOW enzymes denature.
   breaks H bonds that hold them in 3D shape.
   active site changes shape no longer works as a catalyst. metabolic reactions less efficient
2. highest rate at optimum (around 7)

Question 3

importance of maintaining blood glucose concentration

Answer 3

(cells need glucose for energy and affects the water potential)

1. TOO HIGH water potential reduced to point where water molecules diffuse out of cells into blood by osmosis. shrivel up and die
2. TOO LOW cells unable to carry out normal activities isn’t enough glucose for respiration to provide energy

Question 4

pathway

Answer 4

receptors detect deviation from optimum

info communicated via nervous system or hormonal system to effectors

Question 5

negative feedback

Answer 5

restores level to normal

only works within certain limits (not if change too big)

Question 6

multiple negative feedback systems mean

Answer 6

faster response and more control (than just the one)

Question 7

positive feedback

Answer 7

amplifies the change

e.g. when more sodium channels open during an action potential