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ENZYMES
1-Which one of the followings doesnt increase the rate of enzymatic reactions ?
A- Temparature B- Light C- pH
D- Enzyme quantity E- Substrate quantity
2. Which of the following is false for enzymes?
A)Can use again and again
B)It can work out of the cell
C)one type of enzyme can use in all reaction
D) They contain protein
3. Which of the following substances dont use in enzyme synthesis?
A) Water B) ATP C) Ribosome D) Enzyme E) Amino Acid
4. Enzymes are synthesized, packed and stored in some organelles? Which of the followings are given respectively?
a)ribosome-lysosome-golgy b) golgi-ribosome-ER
c) ER-ribosome-golgi d) Ribosome-golgi-lysosome
e) ER-golgi-lysosome
5- Which of the following does not affect the enzyme activity ?
a) pH b) Temparature c) Enzyme concentration d) Substrate concentration e) Light
6- The best description of an enzyme is that is
a)Becomes hydrolyzed during chemical reactions
b) Becomes dehydrated during chemical synthesis
c) Speeds up the rate of chemical reactions
d) Serves as an inorganic catalyst
e) is the source of energy for a chemical reaction
7- A substrate is the substance
a)From which an enzyme is formed
b) By which an enzyme is deactivated
c) On which an enzyme acts
d) With which an enzyme forms bonds
e) By which an enzyme is phosphorylated
8- The function of an enzyme is to
a) cause chemical reactions that would not otherwise take place.
b) change the rates of chemical reactions.
c) control the equilibrium points of reactions.
d) change the directions of reactions.
9- Which of the following is/are not properties of enzymes?
a)Metabolic reactions are performed by the coenzyme component of an enzyme.
b)Every enzyme has its unique coenzzyme.
c)A coenzyme determines the type of substrate affected by an enzyme.
d) A coenzyme degrades or combines substrates.
e) A coenzyme may function with different enzymes.
10-Which is only correct statement about the enzymes shown above?
a) They are not effected by changes in pH.
b) They generally function in acidic conditions.
c) They generally function in alkaline conditions.
d) They have an optimum pH
e) They are less active in conditions of neutral pH.
11- A piece of fresh liver is mashed and placed in a test tube together with 2 ml of H2O2.An intact piece of liver together with 2 ml of H2O2.is pleaced into a second test tube .IT is observed that in the second tube.
According to the information given above, which the following explain the increase in the rate of reaction?
a) The enzyme concentration changes
b) The substrate concertration changes
c) The pH changes
d) The tempreture changes
e) Inhibitors slow the reaction down
12--Which of the following properties are shared by both coenzymes and cofactors?
a) Composed of organic molecules
b) Synthesised in cells
c) Composed of metal ions
d) Function as enzyme activators
e) Participate to the structure of proteins
13-- Which of the following factors affect the enzyme activity?
a) Temparature b) pH c) Enzyme concentration
d) Substrate concentration e) All
14-. The enzyme involved in oxidation-reduction of a substance cannot operate without NAD. The NAD is known as :
a). cofactor b). prosthetic group c). coenzyme d). amino acid e). coenocytic
15-- Enzymes accomplish each of the following EXCEPT
A- Increase the rate of the forward reaction
B- Increase the rate of the reverse reaction
D- Increase the activation energy of the reaction
E- Allow reactions to occur more readity
16-- Organics moleculers, such as vitamin C and vitamin B12, are required for specific enzymes
to function. Such organic molecules are called
A- substrates
B- coenzymes
C- allosteric modulators
D- active sites
E- competitive inhibitors
17- An enzyme functions to increase the rate of a reaction by
A). İncreasing the concentration of the substance
B). Decreasing the energy of activation
C). Competing with the substrate
D). Breaking down atp
E). Hydrolyzing the substrate