Enzymes; Nucleic Acids and Protein Synthesis Flashcards
Enzymes increase the rates of only certain reactions involving certain substances. This general characteristic is called ___________.
Select one:
a. selectivity
b. enzyme regulation
c. specificity
d. catalytic efficiency
c. specificity
An inactive form of an enzyme is called
Select one:
a. a cofactor
b. a proenzyme
c. an apoenzyme
d. an activator
c. an apoenzyme
_____________________ is an example of a cofactor required by an enzyme.
Select one:
a. Acetyl coenzyme A
b. The ferrous (Fe2+) ion
c. Lipoamide
d. The sodium ion
b. The ferrous (Fe2+) ion
A metal ion required for enzyme activity is called
Select one:
a. a cofactor
b. a proenzyme
c. a substrate
d. a zymogen
a. a cofactor
Which statement about enzymes is incorrect?
Select one:
a. Enzymes can either speed up or slow down a chemical reaction
b. Enzymes are not used up during the chemical reaction in which they are involved
c. Enzymes are proteins that are capable of reducing the activation energy
d. There are enzymes that interact with one enantiomer, but not the other
a. Enzymes can either speed up or slow down a chemical reaction
A zymogen is correctly classified as
Select one:
a. an organic cofactor for an enzyme
b. an inorganic cofactor for an enzyme
c. a coenzyme
d. an inactive precursor of an enzyme
d. an inactive precursor of an enzyme
What is the reason for performing an enzyme assay?
Select one:
a. to determine the number of enzyme molecules per liter
b. to determine the number of enzyme molecules per mL
c. to determine the activity of an enzyme
d. to determine the number of enzymes present
c. to determine the activity of an enzyme
The substrate for the digestive enzyme names sucrase is
Select one:
a. glucose
b. fructose
c. sucrose
d. lactose
c. sucrose
What is the function of an inhibitor?
Select one:
a. to slow down the rate of reaction
b. to inhibit the effect of temperature and pH changes on enzyme activity
c. to inhibit the effect of the substrate on other chemicals in the reaction environment
d. to slow down the interaction between the solvent and the substrate
a. to slow down the rate of reaction
Which of the following terms is a general definition of an enzyme?
Select one:
a. a catalyst
b. a lipid
c. a carbohydrate
d. an activator
a. a catalyst
The theory that proposes a somewhat flexible enzyme conformation is the
Select one:
a. lock-and-key theory
b. induced-fit theory
c. physically-fit theory
d. expanding-fit theory
b. induced-fit theory
Which of the following is a common function of many vitamins in the body?
Select one:
a. substrates
b. apoenzymes
c. coenzymes
d. activators
c. coenzymes
An enzyme is known to catalyze the conversion of proteins to amino acids. Which of the following would be a correct designation for the enzyme?
Select one:
a. a transferase
b. an oxidoreductase
c. a hydrolase
d. lyase
c. a hydrolase
The region of an enzyme where the substrate molecule fits is called the
Select one:
a. active site
b. substrate site
c. substrate bond
d. primary site
a. active site
An enzyme is operating at a pH that is its optimum pH. If the pH were increased, how would the rate of the enzyme-catalyzed reaction change?
Select one:
a. increase
b. decrease
c. could increase or decrease
d. would not change
b. decrease
Which statement does not apply to the lock and key theory?
Select one:
a. explains the functioning of enzymes
b. explains the need for a specific three dimensional structure found in proteins
c. explains the reason why a particular enzyme is involved with one substrate
d. explains why a substrate-enzyme complex is so difficult to separate
d. explains why a substrate-enzyme complex is so difficult to separate
Which of the following terms can be used correctly to fill the blank in the following equation?
apoenzyme + ________ –> active enzyme
Select one:
a. zymogen
b. cofactor
c. isozyme
d. substrate
b. cofactor
