Unit 2 - Metabolism and Survival (Metabolism in Conformers and Regulators) Flashcards
(11 cards)
What abiotic factors affect an organism’s ability to maintain its metabolic rate?
- Temperature
-Salinity - pH
What are conformers?
Organisms that are dependent upon the changes in the external environment.
What are regulators?
Organisms that can control their internal environment regardless of external environmental change.
How do conformers maintain an optimum metabolic rate?
- Conformers must change their behaviour in order to survive under extreme circumstances. Behavioural responses by conformers include reducing their activity when the environmental temperature falls.
- Behavioural responses by conformers allow them to tolerate variation in their external environment to maintain optimum metabolic rate.
- A common way in which conformers maintain an optimum temperature is to bask in the sun and absorb the heat energy directly or from the ground around them.
- Conformers have low metabolic costs and have a narrow range of ecological niches.
How do regulators maintain an optimum metabolic rate?
- Regulators use metabolism to control their internal environment, which increases the range of possible ecological niches.
- The regulation requires energy to achieve homeostasis. This increases their metabolic costs.
What is the role of the hypothalamus during homeostasis?
The hypothalamus is the temperature monitoring centre in the brain. It is sensitive to nerve impulses that come from receptors in the skin. The hypothalamus then sends nerve impulses to effectors to change the temperature of the body.
What are some examples of effectors?
Effectors include sweat glands, blood vessels and muscles around the body.
What is negative feedback?
Negative feedback control is the mechanism used to control the temperature of the body.
What corrective responses are made to reduce body temperature?
- Vasodilation (where blood vessels allow blood to flow to the skin’s surface where heat is lost through radiation).
- Increased sweat rate (heat is lost through turning sweat into vapour, which lowers body temperature as it evaporates).
- Decrease in metabolic rate (a lower metabolic rate produces less heat).
What corrective responses are made to increase body temperature?
- Vasoconstriction (blood vessels are restricted and blood flow to skin stops so less heat is lost).
- Hair erector muscles contract (hairs stand on end and trap an insulating layer of warmer air next to the skin).
- Shivering (skeletal muscles around the body repeatedly contract and this muscle activity generates heat).
What is the importance of regulating temperature (thermoregulation).
Regulation of temperature allows for optimal enzyme activity and high diffusion rates to maintain metabolism (keeps the optimum temperature for enzyme activity, provides enough energy for molecules to diffuse at a sufficient rate).
