BICH 409- EXAM 3 UPDATED ACTUAL QUESTIONS
AND CORRECT ANSWERS
Question:
1. competitive inhibitor effects
Answer:
vmax is unchanged, km increased, lines intersect at y-axis, ki= I/(mi/mo-1)
Question:
2. Uncompetitive inhibitor effects
Answer:
decreases both km and vmax, lines are parallel and do not intersect, ki = I-(bi/bo
-1)
Question:
3. Noncompetitive inhibitor effects
Answer:
decreases the vmax, km is unchanged, lines intersect at x-axis, ki = I/(mi/mo -1) OR
ki= I/(bi/bo - 1)
Question:
4. Mixed noncompetitive inhibitor effects
Answer:
decreases the vmax and changed the km, lines intersect between the x and y axis,
not at a specific one, ki= I/(mi/mo -1) ki' = I/(bi/bo -1)
Question:
5. kcat
Answer:
turnover number, the number of substrate convrted to product per enzymes
molecule per unit of time, =vmax/Eo, units of time
Question:
6. catalytic efficiency
Answer:
kcat/km, the estimate of how perfect an enzyme is, units = M-1s-1
, Question:
7. lineweaver-burk
Answer:
x-axis = 1/S, y-axis = 1/vo, Km= x-int, Vmax = y-int
Question:
8. irreversible inhibition
Answer:
covalently modified enzyme that destroys catalytic activity, no lineweaver burk
plot
Question:
9. Multisubstrate enzymes
Answer:
enzymes that bind 2 substrates like transferases, oxidoreductases, ligases and
liases
Question:
10. two types of bi-bi reactions
Answer:
Sequential and ping-pong
Question:
11. sequential mechanisms
Answer:
all substrates must bind before the reaction occurs, then all products are released
Question:
12. ordered sequential mechanisms
Answer:
the substrates must bind in sequential order
Question:
13. random sequential mechanisms
Answer:
both substrates must bind before the reaction occurs and the products are
released, but there is no preference to the order of substrate binding
AND CORRECT ANSWERS
Question:
1. competitive inhibitor effects
Answer:
vmax is unchanged, km increased, lines intersect at y-axis, ki= I/(mi/mo-1)
Question:
2. Uncompetitive inhibitor effects
Answer:
decreases both km and vmax, lines are parallel and do not intersect, ki = I-(bi/bo
-1)
Question:
3. Noncompetitive inhibitor effects
Answer:
decreases the vmax, km is unchanged, lines intersect at x-axis, ki = I/(mi/mo -1) OR
ki= I/(bi/bo - 1)
Question:
4. Mixed noncompetitive inhibitor effects
Answer:
decreases the vmax and changed the km, lines intersect between the x and y axis,
not at a specific one, ki= I/(mi/mo -1) ki' = I/(bi/bo -1)
Question:
5. kcat
Answer:
turnover number, the number of substrate convrted to product per enzymes
molecule per unit of time, =vmax/Eo, units of time
Question:
6. catalytic efficiency
Answer:
kcat/km, the estimate of how perfect an enzyme is, units = M-1s-1
, Question:
7. lineweaver-burk
Answer:
x-axis = 1/S, y-axis = 1/vo, Km= x-int, Vmax = y-int
Question:
8. irreversible inhibition
Answer:
covalently modified enzyme that destroys catalytic activity, no lineweaver burk
plot
Question:
9. Multisubstrate enzymes
Answer:
enzymes that bind 2 substrates like transferases, oxidoreductases, ligases and
liases
Question:
10. two types of bi-bi reactions
Answer:
Sequential and ping-pong
Question:
11. sequential mechanisms
Answer:
all substrates must bind before the reaction occurs, then all products are released
Question:
12. ordered sequential mechanisms
Answer:
the substrates must bind in sequential order
Question:
13. random sequential mechanisms
Answer:
both substrates must bind before the reaction occurs and the products are
released, but there is no preference to the order of substrate binding
