2.4 Metabolism in Conformers & Regulators Flashcards
describe ‘the term conformer’
an organism whose internal environment is dependent on the external environment
describe ‘the term regulator’
an organism which can use metabolism to control its internal environment
what is metabolism affected by?
external abiotic factors (e.g. temperature, salinity and pH)
what is homeostasis?
the maintenance of the body’s internal environment, despite changes int he external environment
compare conformers with regulators (e.g. examples of organisms, metabolic cost and range of ecological niches)
Conformers
- examples of organisms = fish, amphibians and reptiles
- metabolic cost = low
- range of ecological niches = narrow
Regulators
- examples of organisms = birds and mammals
- metabolic cost = high
- range of ecological niches = wide
describe ‘negative feedback control’
A factor can increase or decrease from its norm or set point. This is sensed by receptors for that factor. Messages are sent from the receptors to the effectors, which bring about a corrective response to lower or raise the factor back to its norm or set point.
what term describes a regulators ability to control its internal body temperature?
thermoregulation
where are receptors that detect changes in core body temperature found within the brain?
in the hypothalamus
name 2 effectors involved in the maintenance of core body temperature
- hair erector muscles
- skin arterioles
- sweat glands
- skeletal muscles
describe ‘how hair erector muscles respond to a decrease in core body temperature’
Hair erector muscles contract and hair stand on end. This taps more air against the skin (more insulation). Reduced heat loss by radiation.
describe ‘how skin arterioles respond to an increase and a decrease in core body temperature’
Skin arterioles widen and more blood flows to the surface of the skin. This increases heat loss by radiation.
Skin arterioles narrow and less blood flows to the surface of the skin. This decreases heat loss by radiation.
describe ‘how sweat glands respond to an increase in core body temperature’
When sweat evaporates (because of body heat), it cools the skin. This increase sweat production.
describe ‘how skeletal muscles respond to a decrease in core body temperature’
The contraction of skeletal muscles generates heat.
why is it important that animals regulate their core body temperature?
so they can maintain metabolism by achieving:
- optical enzyme activity (enzymes are most active at certain temperatures)
- high diffusion rates
