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24 Cards in this Set
- Front
- Back
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What is the optimum pH for an enzyme? Optimum temp? |
depends which enzyme and where it usually acts *pepsin = low pH cause its in the stomach *Trypsin = high pH cause works in small intestine low pH would denature it Same idea with temp |
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activation |
any process that starts or increases the action of an enzyme |
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inhibition |
process that slows or stops the action of an enzyme |
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feedback control?? |
regulation of an enzyme's activity by the product of that reaction or a reaction later in the pathway *efficient *no energy is wasted making ingredients for a plentiful substance |
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Allosteric Control *what *two kinds *example |
-regulator binds at one site of protein and affects the protein's ability to bind to another molecule at a different site -positive or negative -lots of drugs work this way |
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Negative allosteric control |
stops of slows rxn negative regulator will bind and cause the active site to disappear or change shape |
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Positive allosteric control |
starts or speeds up rxn positive regular will bind and cause the active site to appear or change shape |
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Reversible inhibition |
inhibitor can leave |
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irreversible inhibition |
inhibitor remains permanently bound enzyme is permanently inhibited |
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Two forms of enzyme regulation (rate): |
1. Allosteric control (pos or neg) 2. inhibition (reversable or nonreversable) |
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Competitive inhibition |
binds to active site and substrate cant enter |
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noncompetitive inhibition |
binds to a different site that is not the active site |
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competitive inhibitor affects on the graph: -compared to no inhibition curve -1/2 max -Vmax |
-lower -same -higher concentrations eventually overcome the competitive inhibitor and it reaches same Vmax it just takes greater amount of substrate |
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non-competitive inhibitor affects on the graph: -compared to no inhibition curve -1/2 max -Vmax |
-much lower -same cause substrate can still bind -different,***lower! |
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Competitive inhibitors and substrates are ______________ |
mutually exclusive |
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The site that is NOT the active site is called |
allosteric site |
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In noncompetitive inhibition: Substrate can still _____________ but _____________ is changed or cant change so _______ |
-bind (Km is same) -shape -Vmax decreases enzyme is inhibited |
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What else can be used to regulate the rate of an enzyme reaction? |
phosphorylation Kinase takes a phosphate from ATP and put it on "target protein" Phosphatases removes phosphate by hydrolysis |
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Zygomens -what -when would you want this? |
-inactive or not complete form of a protein a little piece of it must be cut off -blood clotting or protein digesting enzymes |
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Penicillin -is an example of what? -inhibits what? -what does it do? -active part of the drug? |
-competitive inhibitor -active site of glycoprotein transpeptidase -binds glycoprotein transpeptidase to serine residue in active site -Beta - lactam ring |
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Presence of penicillin stops ____? |
bacteria from making cell walls and they burst |
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two types of resistance from penicillin? |
1. altered glycoprotein transpeptidase to peptidase that doesnt bind with penicillin as well 2.new enzyme that cleaves the Beta-lactam of penicillin called penicillinase |
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New Penicillin? |
Methicillin resistant to cleavage by B-Lactamase but still fits into glycoprotein peptidase |
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cephalosporin |
4th generation penicillin cause it keeps evolving |
