B3.3.1 Controlling Body Temperature

Question 1

What is the optimum temperature for your enzymes

Answer 1

37

Question 2

At what temperatures are you at risk of hypothermia

Answer 2

<35

Question 3

State why metabolic rate slows when body temperature drops

Answer 3

Body temperature drop slows metabolic rate due to reduced enzyme efficiency at lower temperatures
The KE of the molecules decrease, reducing frequency/effectiveness of enzyme substrate collisions

Question 4

State which body system monitors and controls your internal body temperature.

Answer 4

Thermoregulatory

Question 5

What physically happens when you get too hot

Answer 5

Body hairs to lower so the hairs on your skin lie flat - prevents an insulating layer of air being trapped around the body.

Sweat glands produce sweat, as the water in sweat evaporates, energy is transferred by heating from your body to the environment -this reduces your temperature.

Blood vessels supplying capillaries (arterioles) near the surface of your skin to widen -vasodilation
Increases blood flow through the capillaries, and heat loss by radiation

Question 6

What happens when you get too cold

Answer 6

Body hairs rise, trapping a layer of air close to the skin -this insulates the body.

Sweat glands stop producing sweat.

Blood vessels supplying capillaries near the surface of your skin narrow (vasoconstriction).
This reduces blood flow through the capillaries, reducing heat loss.

Shivering begins, it occurs when your muscles contract and relax quickly.
This makes your cells respire quicker, transferring extra energy by heating.

Question 7

Why does temperature need to be controlled?

Answer 7

To provide a suitable environment for enzymes so that they can work fastest at their optimum temp