Lecture 5

Question 1

Why are internal and external temperatures so important?

Answer 1

Internal temperature - the efficiency of the molecular reactions within cells, temp dependent

external temperature, for some animals (poikilotherms) the external environmental temperature correlates to internal, and therefore alters efficiency

Question 2

Temperature vs heat

Answer 2

heat refers to amount of energy in object, where temperature refers to the intensity of the heat

Question 3

what are some of the ways heat travels in the environment?

Answer 3

convection - movement of heat via fluids

conduction - heat transferred via touch

radiation - heat moves in waves

evaporation - change of liquid to gas

Question 4

Pokilotherms/ectotherms

Answer 4

They are temperature dependent and have acute and chronic responses to temperature change

Question 5

What does an acute response to temperature look like?

Answer 5

poikilotherms show a significant relation between its body temperature and environment, via Q10

Question 6

What does a chronic response to temperature look like?

Answer 6

there are 2 ways the body will react

acclimation, or acclimatization

Question 7

What are thermal performance curves and its significance

Answer 7

1. Peak = Thermal optimum (To)
2. Pejus range = performance is in
   decline with increasing
   temperatures
3. High and low critical
   temperatures = Critical thermal
   maximum and minimum (CTmax
   and CTmin)
   * The temperature range between these values is referred to an animal’s thermal breadth

Question 8

How does the body respond to freezing?

Answer 8

Ice formation inside cells is lethal and animal’s need to either avoid or prevent
intracellular freezing, or be able to survive the death of their cells.

Freeze-intolerant (freeze avoiding)
* Produce antifreeze compounds by Suppressing the growth of ice-crystals
by binding to ice-crystals as they begin to form and prevent growth

Freeze tolerant
* Extracellular freezing is safe and helps prevent
intracellular freezing
* Promote extracellular freezing by limiting
the supercooling point (produce ice-
nucleating molecules)