2.4 Metabolism in Conformers and Regulators Flashcards
(26 cards)
What can affect an organisms ability to maintain its metabolic rate?
External abiotic factors
Define ‘abiotic factor’
Non-living chemical and physical parts of the environment that affect living organisms
State the three main abiotic factors
- Temperature
- Salinity
- pH
Salinity = how salty water/soil is
How organisms maintain their metabolic rate classifies them as either ______ or _______
- Conformer
- Regulator
Define ‘conformer’ in the context of metabolic rate
organisms internal environment is dependent upon external environment.
e.g. snakes and fish
Define ‘regulator’ in the context of metabolic rate
maintain their internal environment regardless of external environment.
e.g. mammals and birds
Outline the key characteristics of a conformer
- Internal body environment dependent upon external environment
- Low metabolic costs
- Narrow ecological niche.
- Use behavioural responses to maintain an optimum metabolic rate.
How do conformers maintain their internal environment?
Use behavioural responses to maintain an optimum metabolic rate.
Outline the key characteristics of a regulator
- Maintain constant internal body environment regardless of external environment using metabolism.
- Homeostasis has higher metabolic costs.
- Wider ecological niche.
How do regulators maintain their internal environment?
Using their metabolism
Conformers have a narrower ecological niche than regulators. What does this mean?
An individual conformer is an unlikely to be able to survive in different ecosystems, but a regulator is more likely
e.g. humans occupy many different ecosystems but a lizard needs warmth
Define ‘homeostasis’
a process by which biological systems maintain a constant internal environment, regardless of the external environment
What does homeostasis require to be possible?
Energy
Define ‘thermoregulation’
A type of homeostasis that maintain an organism’s body temperature
Explain why regulating internal temperature is important?
- Optimal enzyme activity
- Fast diffusion rates
Both help maintain constant metabolism
State the temperature monitoring centre of the human body?
hypothalamus
Explain how the hypothalamus regulates body temperature
Sends electrical impulses through nerves to the effectors which bring about corrective responses maintain body temperature
Define ‘negative feedback loop’
When a level goes up this triggers an action that will bring that level back down to normal
Explain how thermoregulation is an example of a negative feedback loop
When the body temperature changes above or below the normal level the hypothalamus triggers effectors to decrease or increase the body temperature.
State the effectors involved in thermoregulation
- Muscles
- Body hair
- Sweat glands
- Skin blood vessels
- Metabolic rate
Describe how the body responds to a decrease in internal temperature?
- Muscles - shivering increases muscle activity generating heat
- Body hair - hair erector muscles contract pulling body hair into a raised position. This traps insulating air
- Skin blood vessels - vasoconstriction causes blood to be diverted away from the skin’s surface reducing heat loss by radiation.
- Metabolic rate - increases to generate more heat
Describe how the body responds to a increase in internal temperature?
- Sweat glands - sweat is released on the skin’s surface. Body heat used to evaporate water in sweat, cooling the skin.
- Skin blood vessels - vasodilation causes blood to be diverted towards the surface, increasing heat loss by radiation.
- Metabolic rate - decreases to reduce heat production
Describe how skin blood vessels respond to a increase in body temperature
Vasodilation - Blood is diverted towards the surface, increasing heat loss by radiation.
Describe how skin blood vessels respond to a decrease in body temperature
Vasoconstriction - Blood is diverted away from the skin’s surface reducing heat loss by radiation.
