Metabolism in Conformers and Regulators Flashcards
What external factors affect an organism’s ability to maintain its metabolic rate?
- pH
- salinity
- temperature
How do animals and plants adapt to changes in external abiotic factors?
- avoidance
- conforming
- regulating
What is a conformer?
An organism whose internal environment is dependant on its external environment - it cannot alter their normal metabolic rate by physiological mechanisms.
How might conformers’ behaviour change to tolerate variation in their external environment?
To maintain their optimum metabolic rate they might bask in the sun to absorb heat energy or burrow in the sand to cool down.
What are the advantages and disadvantages of conformers?
Advantages:
- low metabolic costs = save energy
Disadvantages:
- restricted to a narrow ecological niche as it is less adaptable.
What is a regulator?
An organism that uses energy from their metabolism to maintain their internal environment at a steady state regardless of changes to their external environment.
What are the advantages and disadvantages of regulators?
Advantages:
- can live in a wide range of ecological niches
Disadvantages:
- high metabolic costs
What is homeostasis?
Where an organism maintains a constant internal environment irrespective of the external environment.
How is homeostasis controlled?
By negative feedback.
What is homeostasis essential for?
Thermoregulation
Does homeostasis require energy?
Yes - requires energy from the metabolism.
What is negative feedback made up of?
- receptors
- messages
- effectors
Who uses negative feedback?
Regulators
With negative feedback, when a factor increases above a certain threshold, what happens?
Mechanisms are stimulated to decrease the factor.
With negative feedback, when a factor decreases below a certain threshold, what happens?
Mechanisms are stimulated to increase levels back to their set point.
What is the set point in negative feedback?
The normal level of a factor in the body.
What are receptors in negative feedback?
Detect the level of a factor.
What are messages in negative feedback?
Sent if levels are too low/high. Nervous impulses or hormonal in mammals.
What are effectors in negative feedback?
Parts of the body which carry out a response.
What is the hypothalamus?
The temperature monitoring centre in your brain.
What is thermoregulation?
The process of maintaining your core internal temperature.
What does thermoregulation ensure?
Optimal temperature in the body meaning optimal enzyme activity to main metabolism and high diffusion rates to maintain metabolism.
What parts of the body does thermoregulation involve?
- hypothalamus
- nerves
- effectors
What are responses to an increase in temperature to lower?
- sweating
- vasodilation
- decrease in metabolic rate
How does sweating lower your body temperature?
Body heat is used to evaporate water in sweat which cools the skin.
How does vasodilation lower your body temperature?
Blood capillaries in the skin dilate increasing blood flow to the skin, increasing heat lost by radiation.
How does a decrease in metabolic rate lower your body temperature?
Metabolic reactions generate heat, decreasing the rate reduces heat production.
How might thermoregulation be used to heat up your body?
- shivering
- vasoconstriction of blood vessels
- increase in metabolic rate
- action of hair erector muscles
How does shivering heat up your body temperature?
Rapid involuntary contraction of skeletal muscle generates heat.
How does vasoconstriction of blood vessels heat up your body temperature?
Blood capillaries in the skin constrict decreasing the blood flow to the skin, decreasing heat loss by radiation.
How does an increase in metabolic rate heat up your body temperature?
Metabolic reactions generate heat, increasing the rate increases the temperature.
How do hair erector muscles heat up your body temperature?
Hair erector muscles in the skin contract meaning the hair stands up trapping an insulating layer of air between the hair and skin.
