Homeostasis

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Describe the effect of temperature on the rate of metabolic reactions
as temp increases so does rate because molecules have more kinetic energy so more likely to collide with enzyme. optimum= 37o as too high breaks h bonds in enzyme tertiary structure so reactions stop
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Explain the effect of pH on the rate of metabolic reactions
too high/too low cause h bonds in tertiary structure to be affected so active site not complimentary. optimum usually 7 but depends on enzyme
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What effect does blood glucose concentration have on body cells?
too high=water moves out of cells so they shrivel up. too low=not enough glucose for respiration to provide energy so cells cant work normally
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What are the positive and negative feedback mechanism?
postive=receptor picks up change then effector responds to further increase the chnage (away from normal level) whereas negative=receptor detects too high/too low so effector responds to counteract change (involved in homeostasis), can have multiple
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How are animals classified by their control over their body temperature?
ectotherms-control by changing behaviour, more active at higher temps, havr variable metabolic rate. endotherms-internal control by homeostasis (as well as behaviour), constantly high metabolic rate
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How do mammals lose, conserve and produce heat?
lose: sweating, erector pili muscles relax so less air trapped in hairs, vasodilation=more lost by heat radiation. produce: shivering=increased respiration, hormones increase metabolism. conserve: less sweat, erector pili contract, vascoconstriction
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Whats the role of the hypothalamus in controlling body temperature?
recieves information from thermoreceptors; in hypothalamus detect internal changes, in skin detect external changes. it sends impulses along motor neurones in automic nervous system to effectors
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What is the hormonal response to reducing blood glucose concentration?
Islet of Langerhans (pancrease) has beta cells which secrete insulin. binds to liver/muscle cells 1)increase permeability so take up glucose 2)activates enzyme to convert glucose to glycogen (glycogenesis) 3) increase rate of respiration
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What is the hormonal response to increasing blood glucose concentration?
Islet of Langerhans (pancrease) has alpha cells which secrete glucagon. bind to cells on liver 1)enzyme that breaks down glycogen (glycogenolysis) 2) formation of glucose from amino acids/glycerol (gluconeogensis) 3) decrease rate of respiration
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What is the role of adrenline in controlling blood glucose concentration?
secreted from adrenal glands. binds to receptors on liver cells to activate glycogenolysis and inhibit glycogensis so increase blood glucose concentration and gets you ready for action
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What is the second messenger model?
adrenalina and glucagon bind to receptors on outside activating adenylate inside which converts ATP to cyclic AMP. cAMP is secondary messenger which activates chain of reactions causing glycogenolysis
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Card 2

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Explain the effect of pH on the rate of metabolic reactions

Back

too high/too low cause h bonds in tertiary structure to be affected so active site not complimentary. optimum usually 7 but depends on enzyme

Card 3

Front

What effect does blood glucose concentration have on body cells?

Back

Preview of the front of card 3

Card 4

Front

What are the positive and negative feedback mechanism?

Back

Preview of the front of card 4

Card 5

Front

How are animals classified by their control over their body temperature?

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