Term
| 2 mechanisms that affect enzyme activity |
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Definition
1. control of quantity of enzyme or concentration of substrates present
2. alteration of the catalytic efficiency of the enzyme |
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Term
| What is the relationship of substrate [ ] vs. velocity of product formation |
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Definition
| increase in substrate [ ] will increase the velocity until saturation occurs. |
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Term
| What is the relationship between products formed and time |
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Definition
| as time increases, the amount of product formed doubles |
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Term
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Definition
| macromolecular complexes that uses proteases to degrade protein |
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Term
| is proteolytic degradation reversible or irreversible? |
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Definition
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Term
| degradation regulation of proteasomes that targets proteins |
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Definition
| ubiquination (it can be reversed) |
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Term
| what is an allosteric enzyme? |
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Definition
| reversible, non-covalent binding of a regulatory metabolite at a site other than the catalytic, active site. |
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Term
| what kind of curve will cooperative binding create? |
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Definition
| sigmoidal indicates more than one binding site. |
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Term
| what does the Hill plot describe? |
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Definition
| cooperativity in enzymatic reactions |
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Term
| what happens to a slope with negative cooperativity? |
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Definition
| slope decreases and becomes negative |
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Term
| what happens to the slope in the presence of positive cooperativity? |
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Definition
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Term
| what effect does one substrate binding have on other active sites? |
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Definition
| it changes the active site from tense state to the relaxed state |
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Term
| what is the structure of an inactive protein kinase? |
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Definition
| Regulatory unit, catalytic subunit |
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|
Term
| how does cAMP activate PKA? |
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Definition
| it binds to the regulatory subunit and releases it from the catalyic site |
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Term
| what is homotropic regulation? |
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Definition
| binding of one molecule to a multi-subunit enzyme causes a conformations shift that affect eh binding of the same molecule to another subunit of the enzyme |
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Term
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Definition
| end product of a pathway accumulates as the demand for it delcines |
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|
Term
| what is the function of calmodulin? |
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Definition
| protein cofactor to stimulate activity of target regulatory kinases |
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Term
| What is a common mechanism example of reversible caovalent modification? |
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Definition
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|
Term
| where is phosphorylation most common in terms of AA? |
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Definition
| serine>threonine>tyrosine |
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Term
| What effect does epinephrine play on glycogen synthase? |
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Definition
| phosphorylation inactivates it |
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Term
| what is prenylation, myristoylation, and palmitoylation? |
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Definition
covalent addition of hydrophobic, acyl fatty acid or isoprenoid group to soluble proteins/enzyme.
this also causes proteins to associate w/a membrane rather than cytosol. |
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Term
| what two enzymes are deficient in orotic aciduria? |
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Definition
| orotate phosphoribosyl transferase and orotidine 5 phosphate decarboxylase |
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Term
| a deficiency in the enzymes of orotic aciduria results in what? |
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Definition
| decreased levels of CTP and TTP |
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Term
| a mutation in this synthetase causes gout |
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Definition
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