B2.007 LG Flashcards

1
Q

how do you determine the rate of reaction?

A

slope of concentration vs time

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2
Q

what is the purpose of an enzyme inhibitor?

A

the ligand binds and diminished catalysis to prevent a rxn from occuring

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3
Q

what characterizes a reversible inhibitor?

A

ligand readily dissociates

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4
Q

what characterizes an irreversible inhibitor?

A

ligand does not dissociate before the protein degrades or the patient dies; may be a covalent bond

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5
Q

what are the 3 types of reversible inhibitors?

A

competitive, non-competitive, uncompetitive

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6
Q

what is Km?

A

the [S] at half of vmax

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7
Q

what is on the y axis of a lineweaver-burke plot?

A

1/v0

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8
Q

what is on the x-axis of a lineweaver burke plot?

A

1/[S]

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9
Q

what do the x and y intercepts of the lineweaver-burke plot represent?

A

x axis: Km

y-axis: vmax

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10
Q

how do competitive inhibitors work?

A

compete with substrate for same form/site of the enzyme

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11
Q

which step is affected by competitive inhibition?

A

binding step only

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12
Q

how does a competitive inhibitor affect an enzyme activity curve?

A

Km increases

Vmax stays the same

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13
Q

what does a larger Km indicate?

A

less effective enzyme, takes a higher substrate concentration to get the same result as an enzyme with a lower Km

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14
Q

how to non-competitive inhibitors work?

A

inhibitor can bind to either just the enzyme, or the ES complex and inactivate it

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15
Q

what would be functionally similar to having a non-competitive inhibitor present?

A

having less enzyme

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16
Q

how does non-competitive inhibition affect an enzyme activity curve?

A
Km stays the same
vmax decreases (like having less enzyme)
17
Q

how does uncompetitive inhibition affect an enzyme activity curve?

A

changes Km and vmax

18
Q

how do aspirin and ibuprofen inhibit COX differently?

A

ibuprofen is reversible and is secreted within 24 hrs

aspirin is irreversible and persists until entirely new platelets are made 7-10 days later

19
Q

which type of reversible inhibition does irreversible inhibition mimic on the enzymatic activity curve?

A

non-competitive; less overall enzyme function