Temperature Control in Ectotherms Flashcards
What is an ectotherm?
An organism that relies on external sources of heat to maintain body temperature.
What is an endotherm?
An organism that uses heat from metabolic reactions to maintain body temperature.
Give some examples of ectotherms.
Snake
Lizard
Locust
Horned lizard
What is affected when the body temperature increases?
Molecules have more kinetic energy so essential chemical reactions occur more quickly.
Structure of proteins can also be affected.
How can an increase in body temperature affect proteins, specifically enzymes?
The shape of the active site will change and if the temperature continues to rise it will completely denature and no long work as an enzyme.
What do ectotherms do if they are not warm enough?
Move into a sunny area
Lie on a warm surface
Expose a larger surface area of their skin to the sun
If ectotherms are too hot what do they do?
Move out of the sun
Move underground
Reduce the body surface area exposed to the sun
What does a snake do to increase their body temperature?
Bask in the sun.
What do locusts do to increase their body temperature?
In the early morning, locusts sit side-on to the sun exposing the largest surface area. At midday they face the sun exposing a smaller surface area to the sun. They may also climb to the tops of plants to get away from the soil surface.
Increases both the rate of the breathing and the depth of the movements when its hot.
What does a lizard do to control it’s temperature?
Use burrows or crevices between rocks to cool off. Hide in the burrow during hottest part of the day and the coolest part of the night.
What is the behavioural adaption of a horned lizard?
Can change its shape by expanding or contracting its ribcage. This is to increase it’s surface area so that the sun warms it up.
What are the advantages of ectothermy?
Less of their food is used in respiration
More of the energy and nutrients gained from food can be converted to growth
They need to find less food
They can survive for long periods without food
What are the disadvantages to ectothermy?
They are less active in cooler temperatures
They are more at risk from predators while they are cold and unable to escape and they cannot take an advantage of food that is available while it is cold.
Why is the core body most important?
All the vital organs are found at the centre of the body. Peripheral parts may be allowed to lose their temperature to some extent without affecting the survival of the organism.
