Term
| in 1850 what did Whilhelmy show between the rate of acid hydrolysis of sucrose to its concentration? |
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Definition
| rate of acid hydrolysis of sucrose is proportional to sucrose concentration at a constant acid concentration |
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Term
| enzymes become ............... with substrate at higher.............. concentrations. the only way to ....... reaction rate under these conditions is to ........ more enzyme. this is also used as ....... for the formation of a discrete enzyme-substrate complex intermediate between substrate and products |
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Definition
saturated, substrate, increase, add, evidence
what is the shape of the enzyme rate curve?
its a rectangular hyperbolic curve |
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Term
| what is the Michaelis-Menten equation? What does Vmax and Km stand for? |
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Definition
v = Vmax [S]/Km + [S]
Vmax is the max rate of reaction
Km is the Michaelis constant and represents the substrate concentration at which the rate of reaction is half-maximal |
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Term
at low substrate concentrations the rate is ................. to substrate
at high substrate concentrations the rate is ....................... of substrate |
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Definition
proportional, independant
Km is expressed in units of concentration (M) |
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Term
Km represents the substrate concentration at which the rate of reaction is half-maximal. Alternatively Km represents the substrate concentration at which half theactive sites are occupied
out of Km and V max which is a constant? |
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Definition
Km is a constant. for many enzymes Km approximates the affinity of the enzyme for the substrate
Km is a constant that defines the interaction between enzyme and substrate molecules
It is independant of the amount of enzyme and substrate present |
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Term
A low value for Km means high affinity substrate binding ie, strong/tight binding
here enzyme binds substrate even at low concentrations.
In many cases Km is close to the in vivo substrate concentration. what does this mean? |
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Definition
if you looked inside a cell for a particular enzyme, the Km of that enzyme would be close to the concentration of the enzyme when found in a cell.
if you have the same enzyme Km is always going to be the same. |
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Term
| is Vmax a constant? what does V max tell us? |
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Definition
V max is NOT a constant. It tells us how many enzymes there are. The measured value for Vmax only applies to one particular reaction condition.
Adding more enzyme will increase Vmax BUT NOT Km |
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Term
| when enzyme A has a low Km what do you need to get a faster rate of reaction? |
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Definition
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Term
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Definition
when the enzyme is completely saturated with substrate
the turnover number is the number of substrate molecules converted into product per unit time when the enzyme is fully saturated with substrate
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Term
| name the two types of reciprocal plots availble to plot data |
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Definition
double reciprocal plot The lineweaver-Burk Plot
Reciprocal plot The Eadie-Hoftsee plot |
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