Ectotherms

An organism that relies on external sources of heat to regulate their body temperature.

• changes can have a dramatic effect on the structure of proteins. E.g enzyme and substrate shape must be specific in order to carry out function
• If temperature rises too high enzymes can denature
• Metabolic processes can slow or stop

• Less food needed for respiration
• Eat less so do not need to spend as much time finding food
• More energy can be used for growth

• Less active when cold
• Must warm up in morning
• Greater risk of becoming prey when cold
• Incapable of activity in winter
• Can only live in certain areas

• Expose body to sun, more heat absorbed
• Orientate body to sun, larger surface exposed to sun
• Orientate body away from sun, smaller surface area exposed to sun
• Hide in burrows, keep out of sun to reduce heat absorption
• Alter body shape, expose more or less surface area to sun
• Increase breathing movements, evaporate more water

• Snakes
• Locusts
• Lizards
• Horned Lizards