regulation mechanisms Flashcards

1
Q

what is homeostasis

A

maintenance of constant internal state of the body

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2
Q

what is metabolic flux

A
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3
Q

what does a lower [s] mean

A

more sensitive

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4
Q

what does a higher [s] mean

A

less sensitive

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5
Q

how to maintain a steady state in a reaction

A

all reactions in a pathway proceeds at the same net rate

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6
Q

why is AMP a more sensitive indicator of a cells energy state than ATP

A

a decrease in [ATP] greatly affects the activity ATP utilizing enzymes which leads to a dramatic increase in [AMP]

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7
Q

AMP production from ATP equations

A

ATP–>ADP+Pi
2ADP–>ATP+AMP

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8
Q

what does AMPK stand for

A

AMP-activated kinase

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9
Q

what does an increase in exercise or decrease in nutrients cause

A

increase in [AMP] and AMPK activity and glucose transport and glycolysis

decrease in fatty acid, cholesterol and protein synthesis

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10
Q

what are enzymes and what do they do

A

biocatalysts, accelerate biochemical reactions, operate under mild conditions, optimal conditions vary, remain unchanged after reaction, provides alternate pathway with lower Ea, free energy unchanged, equilibrium not affected

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11
Q

what regulates enzyme activity

A

substrate availability, conc of enzymes (balance between transcription and regulation), activity of enzymes (reversible allosteric interactions, reversible covalent modifications [de/phosphorylation]), availability of cofactors

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12
Q

what does protein kinase do

A

catalyse phosporylation

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13
Q

what does protein phosphatases do

A

catalyse dephosphorylation

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14
Q

where are proteins typically phosphorylated

A

hydroxyl group of serine/threonine/tyrosine

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15
Q

what are prosthetic groups

A

tightly bound coenzymes

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16
Q

how do availability of cofactors regulate enzyme activity

A

can be non/covalently bound to enzyme, necessary for some enzymes to become catalytically active, metals (important in nutrition for enzymatic catalysis)

17
Q

what are coenzymes

A

organic molecules that act as cofactors

18
Q

where are coenzymes from

A

vitamins or derived from vitamins

19
Q

what is allosteric activation

A

activator binds and increases function of active site and increases binding of substrates

20
Q

what is allosteric inhibition

A

inhibitor binds and active site undergoes conformational changes and enzyme activity decreases, substrate not complimentary anymore

21
Q

describe glycolysis in short (products)

A

glucose, glucose-6-phosphate, fructose-1,6-bisphosphate, phosphoenolpyruvate, pyruvate

22
Q

how many isozymes are there of hexokinase

A

4

23
Q

function of hexokinase in muscle and liver

A

muscle- consumption of glucose for energy

liver-maintenance of blood glucose

24
Q
A