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24 Cards in this Set
- Front
- Back
What are enzymes? |
Proteins that function as catalysts to speed up chemical reactions. |
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How do enzymes speed up chemical reactions? |
They lower the activation energy of a reaction by leading the reaction through a different chemical pathway with a lower activation energy. |
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What is a metabolic pathway? |
A series of linked reactions starting with a reactant and ending with an end product. |
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What're some examples of metabolic pathways? |
Citric acid cycle, glycolysis, urea cycle |
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True or false? Enzymes can only catalyze one specific reaction. |
True. It is referred to as the "lock and key model." |
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In the lock and key model, what is the enzyme and what is the substrate? |
The enzyme is the lock and the substrate is the key. |
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Where does the substrate bind to the enzyme? |
the active site |
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When an enzyme undergoes a change in shape in order to fit into the active site, what is it called? |
induced fit |
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What is the Enzyme Catalyst 3 step process? |
1. Initiation 2. Transition state facilitation 3. Termination |
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What happens during initiation? |
Reactants are oriented to react by enzymes as the reactants bind to the active sites |
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What happens during transition state facilitation? |
-Binding induced the format of the transition state -The interaction between the enzyme and the substrate lowers the activation energy required for the reaction |
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What happens during termination? |
-The products have less affinity for the active site and are released -Enzyme returns to original shape (they cannot be used up) |
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What factors affect enzymes? |
-Substrate concentrations -Temperature -pH |
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What is substrate concentration and how does it affect an enzyme? |
Substrate concentration is the increased amount of substrate molecules that cause the product to be created faster as the active site is constantly filled up. |
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How does temperature affect the substrate and the enzyme interaction? |
The higher the temperature, the increased enzyme activity. The movement of the molecule is faster, thus more collisions and a sped up reaction. |
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What happens if the temperature rises passed a certain point? |
The enzyme is denatured. |
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Define denatured |
This is when the shape of the enzyme has been altered so that it may no longer combine with the substrate. |
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How does pH affect an enzyme? |
It can change the shape of it, which denatures it. |
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What are enzyme cofactors? |
Atoms or molecules that are required for the enzyme to function. |
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Coenzymes do what? |
They bind to the active site to stabilize the transition state during the reaction |
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What is competitive inhibition? |
It is when another molecule shaped very similarly to the shape of the active site compete with the true substrate for the active site. |
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What is non-competitive inhibition? |
This is when a molecule bind to a different part of the enzyme called the allosteric site that alters the enzyme shape making the substrate unable to bind to the active site. |
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Poisons are usually examples of what? |
Enzyme inhibitors |
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What does Penicillin do to an active site of an enzyme? |
It blocks it, making the bacteria unable to bind with the active site |