5865474
Descripción
Test por Nada Medhat, actualizado hace más de 1 año
|
|
Creado por Nada Medhat
hace casi 8 años
|
|
Pregunta 1
Pregunta
1- which is true for a denatured enzyme ;
Respuesta
-
a) it looses its native conformation
-
b) its peptide bond are broken
-
c) enzyme solubility increases
-
d) it can still binds its substrate and catalyze the reaction
Pregunta 2
Pregunta
2- initial velocity of an enzyme - catalyzed reaction is which ;
Respuesta
-
a) velocity before adding the enzyme
-
b) velocity before accumulation of product
-
c) velocity at zero substrate concentration
-
d) velocity with substrate concentration equal to Km
-
e) the lowest velocity
Pregunta 3
Pregunta
3- a non competitive inhibitor of an enzyme ;
Respuesta
-
a) increase km with no change in Vmax
-
b) decrease km and Vmax
-
c) increase Vmax with no change in km
-
d) decrease Vmax with no change in km
Pregunta 4
Pregunta
4- a coenzyme is which of the following ;
Respuesta
-
a) the protein part of an enzyme
-
b) an inactive enzyme
-
c) an inorganic cofactor
-
d) a substrate needed for the enzyme action
Pregunta 5
Pregunta
5- an enzyme catalyzes reaction by which of the following mechanism ;
Respuesta
-
a) forcing the reaction against natural equilibrium
-
b) lowering the activation energy of the reaction
-
c) binding the products of the reaction to guarantee its continuity
-
d) giving the reactants energy required to make the reaction
Pregunta 6
Pregunta
6- Michaelis constant equals which of the following ;
Respuesta
-
a) half the substrate concentration that gives Vmax
-
b) the substrate concentration that half saturate the enzyme
-
c) the initial velocity at half saturation of the enzyme
-
d) none of the above
Pregunta 7
Pregunta
7- the effect of methotrexate on dihydrofolate reductase is ;
Respuesta
-
a) increased km with no change in Vmax
-
b) decreased km and Vmax
-
c) no change in km and decreased Vmax
-
increased km and decreased Vmax
Pregunta 8
Pregunta
8-what is meant by induction of an enzyme ;
Respuesta
-
a) increased synthesizes of the enzyme from the gene
-
b) increased kinetic energy of the enzyme
-
c) activation of an inactive enzyme
-
d) enhanced affinity between the enzyme and its substrate
Pregunta 9
Pregunta
9- the effect of allopurinole on xanthine oxidase enzyme ;
Respuesta
-
a) decrease formation of uric acid
-
b) decreases Vmax and no change in km
-
c) the effect can not be reversed by dialysis
-
d) the effect can not be reversed by increasing substrate concentration
-
e) all of the above
Pregunta 10
Pregunta
10- an allosteric molecule is characterized by ;
Respuesta
-
a) can bind covalently to the enzyme
-
b) can bind to the active site of the enzyme
-
c) binds non covalently to the enzyme
-
d) is derived from a vitamine
Pregunta 11
Pregunta
11-which of the following doesn't bind to the active site of the enzyme ;
Respuesta
-
a) the substrate
-
b) the competitive enzyme
-
c) the coenzynme
-
d) the allosteric molecule
-
e) none of the above
Pregunta 12
Pregunta
12-digestive enzyme belong to the class of ;
Respuesta
-
a) hydrolyases
-
b) ligases
-
c) lyases
-
d) transferases
¿Quieres crear tus propios Tests gratis con GoConqr? Más información.