Enzyme Inhibitors,Cofactors & Coenzymes

  • Created by: Aleena
  • Created on: 15-04-19 13:07
inhibitor?
any substance that slows down or stops an enzyme-catalysed reaction by affecting the enzyme in some way
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Non-Reversible Inhibition?
Inhibition that occurs when an inhibitor combines permanently with enzyme & completely inactivate it
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Reversible Inhibition?
The inhibition that occurs when an inhibitor combines temporarily with an enzyme-where inhibition can be reversed & enzyme can become active again
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Competitive Inhibition
Inhibition that occurs when an inhibitior with the same shape as substrate molecule combines with active site -blocking access of substrate
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How can competitive inhibition be reversed?
increasing concentration of substrate molecules
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Examples of competitive inhibitors
Statins-reduce production of cholesterol by combining with cholesterol synthesis enzymes and Aspirin- irreversibly inhibits active site of COX enzymes-prevent production of chemicals that cause pain/inflammation e.g Thromboxane & Prostaglandins
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Non-Competitive Inhibition?
inhibition that occurs when inhibitor binds to allosteric site of enzyme-changes teritary structure,therefore shape of active site.
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Can Non-Competitive Inhibition be reversed by increasing substrate/enzyme concentration?
no because there aren't any functioning active sites to bind with
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Examples of Irreversible Non-Competitive Inhibition?
often toxic e.g. chemicals used in insecticides/herbicides that inhibit enzyme necessary for nerve impulse transmission-leads to paralysis,death,muscle cramps
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End-product inhibition?(negative feedback & non competitive reversible inhibition example)
product of an enzyme-controlled reaction acts as an inhibitor to the enzymes that made it
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Example of end product inhibition?
ATP binds to allosteric site of enzyme PFK-prevent addition of 2nd phosphate group to glucose,so glucose isn't broken down-less ATP produced
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Cofactor?
non-protein substance required by the enzyme to function-they maybe temporarily/permanently attacthed to enzyme
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Coenzyme?examples?
An organic cofactor e.g.vitamin B5 used to make coenzyme A-breaks down fatty acids & carbohydrates in respiration
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Inorganic cofactors? examples?
these are minerals obtained via diet e.g. Amylase needs chloride and calcium ions to break down starch into maltose
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Prosthetic Group?(like cofactors)
a non-protein part of a protein (e.g.enzyme) that is permanently attatched to the molecule & is vital for the normal functioning of the molecule
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Prosthetic Group Example
Zinc ions (Zn2+) form vital part of the structure of carbonic anyhdrase (metabolism of CO2)
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Other cards in this set

Card 2

Front

Non-Reversible Inhibition?

Back

Inhibition that occurs when an inhibitor combines permanently with enzyme & completely inactivate it

Card 3

Front

Reversible Inhibition?

Back

Preview of the front of card 3

Card 4

Front

Competitive Inhibition

Back

Preview of the front of card 4

Card 5

Front

How can competitive inhibition be reversed?

Back

Preview of the front of card 5
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