Term
| At what point in their pathway are enzymes regulated? |
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Definition
| Typically at the beginning, this makes sense physiologically from an efficiency perspective |
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Term
| What are the four main strategies of enzyme regulation? |
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Definition
1. Allosteric Control
2. Multiple forms of enzymes
3. Reversible covalent modification
4. Proteolytic activation |
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Term
| What are the two states of an enzyme? |
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Definition
|
|
Term
| What is the R-State of an enzyme? |
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Definition
|
|
Term
| What is the T-state of an enzyme? |
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Definition
|
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Term
| What allosteric factor inhibits Aspartate transcarbamoylase (ACTase)? |
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Definition
|
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Term
| What allosteric factor has a positive heterotropic effect on Aspartate transcarbamoylase (ACTase)? |
|
Definition
|
|
Term
| How does CTP effect ACTase? |
|
Definition
|
|
Term
|
Definition
| Defined as initial velocity/Vmax |
|
|
Term
| What sort of K' would you see with negative allosteric effects? |
|
Definition
|
|
Term
| What sort of K' would you see with positive allosteric effects? |
|
Definition
|
|
Term
| What factors should one consider when you have competing allosteric factors? |
|
Definition
| affinity and relative concentrations |
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Term
|
Definition
| families of enzymes that catalyze the same reaction. |
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Term
| What are the reversible covalent enzyme modifications? |
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Definition
Phophorylation
Adenylylation
Uridylylation
ADP-ribosylation
Methylation |
|
|
Term
| What are the enzymes of phosphorylation? |
|
Definition
Kinase: puts phosphate on
Phosphytase: takes phosphate off |
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Term
|
Definition
| an inactive protein. Many times potentially destructive proteins are stored and transported as zymogens |
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Term
| What are some examples of zymogens? |
|
Definition
| Digestive enzymes, blood clotting, insulin, collagenase-enzyme, caspases |
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Term
| What is competitive inhibition? What effects does it have on Km and Vmax? |
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Definition
| Competitive inhibition is when substrate analogs compete with substrate for binding spots. In this type of inhibition Km is increased and Vmax is unchanged |
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|
Term
| What are examples of competitive inhibition? |
|
Definition
| Methanol and ethylene glycol as well as methotrexate |
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Term
| How does non-competitive inhibition work? What is the effect on Vmax and Km? |
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Definition
| Noncompetitive inhibition works by binding reversibly on a site different from the site that the substrate binds too. The net effect is to decrease Vmax and leave Km unchanged |
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Term
| What are examples of noncompetitive inhibition? |
|
Definition
| Physiostigmine, captopril, and allopurinol |
|
|
Term
| How does uncompetitive inhibition work? What is the effect on Km and Vmax? |
|
Definition
| These are factors that only bind to enzyme-substrate complexes. They lower both Km and Vmax |
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Term
| What is the effect of irreversibly inhibition on Vmax and Km? |
|
Definition
| Vmax decreases but Km remains unchanged |
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|
Term
| What are examples of irreversible inhibition? |
|
Definition
| Penicillin, Aspiring, and Organophosphates |
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