Term
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Definition
Value of [substrate] which equals 1/2 of Vmax
Determines the enzyme affinity toward substrate:
Smaller Km (small substrate) means HIGHER affinity because only a small substrate concentration needed to achieve 1/2Vmax
Larger Km (large substrate) means LOWER affinity because it takes a large amount of substrate to achieve 1/2Vmax |
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Term
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Definition
| The speed of the reaction at which all the enzymes are occupied with substrate (supersaturated). |
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Term
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Definition
Vd (volume drug was dissolved in) = Amount of drug /Plasma concentration of drug
Rearranged from simply:
Plasma concentration of drug = Amount of drug/Volume that drug was dissolved in |
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Term
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Definition
CL = (0.7 x Vd)/T-halflife
Rearranged to find halflife:
T-halflife = (0.7 x Vd)/CL |
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Term
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Definition
| Loading dose = Cp (target concentration)/ Vd |
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Term
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Definition
Maintenance Dose = Cp(target concentration)/CL
Replace what was lost (Clearance amount) |
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Term
| Competitive Inhibitor effects on Km and Vmax |
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Definition
Km increases (needs more substrate to overcome the inhibitor)
Vmax remains unchanged (inhibitor did not do anything to effect the quality of the enzyme) |
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Term
| Non-Competitive (irreversible) inhibitor effects on Km and Vmax |
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Definition
Km remains the same
Vmax Decreases (allosteric binding of inhibitor causes conformational change of enzyme. Quality of reaction is effected) |
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Term
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Definition
Lethal Dose 50/Therapeutic Dose50
The larger the therapeutic index, the safer the drug is. (higher LD50 and lower TD50) |
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