Enzyme activity is decreased by:
repression of enzyme synthesis
proteolytic degradation of the enzyme
an increase in [product]
all of the above
--------------------------------------------------------
Which of the following are characteristics of the concerted allosteric model of Monod, Wyman, and Changeux?
a. there are at least two forms of the enzyme, termed T and R
b. there is an equilibrium between the T and R form
c. dimeric proteins can have one subunit in the T form and the other in the R form
d. the greater the L value (T/R), the more sigmoidal the v vs. [S] curve will be
e. regardless of the number of subunits in the enzyme, all must be in the T form or all in the R form
f. the level of cooperativity is greatest when KR >> KT
all but c
all but e
a, b, e, and f
a and b only
a, b, d, and e
------------------------------------------------------
Which of the following are characteristics of the concerted allosteric model of Monod, Wyman, and Changeux?
a. there are at least two forms of the enzyme, termed T and R
b. there is an equilibrium between the T and R form
c. dimeric proteins can have one subunit in the T form and the other in the R form
d. the greater the L value (T/R), the more sigmoidal the v vs. [S] curve will be
e. regardless of the number of subunits in the enzyme, all must be in the T form or all in the R form
f. the level of cooperativity is greatest when KR >> KT
all but c
all but e
a, b, e, and f
a and b only
a, b, d, and e
------------------------------------------
Both hemoglobin and myoglobin share all of the following except:
they provide a protein framework that prevents heme-heme interactions with formation of Fe(III)
they are dimers of dimers with few α-α or β-β interactions
they non-covalently bind one heme per globin chain
they have a distal His that sterically hinders CO binding
-------------------------------
A graph of v versus [S] for an enzyme gives a hyperbolic plot. Which one of the following situations cannot give such a plot:
the enzyme obeys Michaelis-Menten kinetics
the enzyme model is an allosteric V system
the enzyme demonstrates positive cooperativity and is in the presence of an activator
the enzyme follows the Monod, Wyman, Changeux model and is in the presence of an inhibitor
All of the above would give a hyperbolic plot
------------------------------------------
Which of the following is something that myoglobin and hemoglobin do not have in common?
oxygenation alters the quaternary structure of both
they both have oxygen bound to the heme at a 120° angle
they are both organized into regions of α helices
they both have two critical histidines that are crucial to their function
they both contain heme
Enzyme activity is decreased by:
repression of enzyme synthesis
proteolytic degradation of the enzyme
an increase in [product]
all of the above
--------------------------------------------------------
Which of the following are characteristics of the concerted allosteric model of Monod, Wyman, and Changeux?
a. there are at least two forms of the enzyme, termed T and R
b. there is an equilibrium between the T and R form
c. dimeric proteins can have one subunit in the T form and the other in the R form
d. the greater the L value (T/R), the more sigmoidal the v vs. [S] curve will be
e. regardless of the number of subunits in the enzyme, all must be in the T form or all in the R form
f. the level of cooperativity is greatest when KR >> KT
all but c
all but e
a, b, e, and f
a and b only
a, b, d, and e
------------------------------------------------------
Which of the following are characteristics of the concerted allosteric model of Monod, Wyman, and Changeux?
a. there are at least two forms of the enzyme, termed T and R
b. there is an equilibrium between the T and R form
c. dimeric proteins can have one subunit in the T form and the other in the R form
d. the greater the L value (T/R), the more sigmoidal the v vs. [S] curve will be
e. regardless of the number of subunits in the enzyme, all must be in the T form or all in the R form
f. the level of cooperativity is greatest when KR >> KT
all but c
all but e
a, b, e, and f
a and b only
a, b, d, and e
------------------------------------------
Both hemoglobin and myoglobin share all of the following except:
they provide a protein framework that prevents heme-heme interactions with formation of Fe(III)
they are dimers of dimers with few α-α or β-β interactions
they non-covalently bind one heme per globin chain
they have a distal His that sterically hinders CO binding
-------------------------------
A graph of v versus [S] for an enzyme gives a hyperbolic plot. Which one of the following situations cannot give such a plot:
the enzyme obeys Michaelis-Menten kinetics
the enzyme model is an allosteric V system
the enzyme demonstrates positive cooperativity and is in the presence of an activator
the enzyme follows the Monod, Wyman, Changeux model and is in the presence of an inhibitor
All of the above would give a hyperbolic plot
------------------------------------------
Which of the following is something that myoglobin and hemoglobin do not have in common?
oxygenation alters the quaternary structure of both
they both have oxygen bound to the heme at a 120° angle
they are both organized into regions of α helices
they both have two critical histidines that are crucial to their function
they both contain heme
