1. Competitive

2. Irreversible

3. Due to enzyme denaturation

4. Uncompetitive

5. Allosteric inhibition

76. An enzyme in saliva which hydrolyzes starch is:

1. α-Amylase

2. Pepsinogen

3. Chymotrysin

4. Malate

5. Maltase

77. Enzymes, which are produced in inactive form in the living cells, are called:

1. Proenzymes

2. Papain

3. Lysozymes

4. Apoenzymes

5. Izozymes

78. The presence of a non competitive inhibitor:

1. Leads to a decrease in the observed Vmax

2. Leads to both an increase in the Vmax of a reaction and an increase in Km

3. Leads to a decrease in Km and Vmax

4. Leads to an increase in Km without affecting Vmax

5. Leads to a increase in Km and Vmax

79. An allosteric enzyme influences the enzyme activity by:

1. Changing the conformation of the enzyme by binding to a site other than catalytic site

2. Competiting for the catalytic site with the substrate

3. Changing the specificity of the enzyme for the substrate

4. Changing the nature of the products formed

5. Changing the nature of the substrates

80. In reversible noncompetitive enzyme activity inhibition:

1. Vmax is reduced

2. Km is increased

3. Km is decreased

4. Vmax is not changed

5. Concentration of active enzyme is reduced

81. Which of the following regulatory reactions involves a reversible covalent modification of an enzyme?

1. Phosphorylation of serine OH on the enzyme

2. Allosteric modulation

3. Competitive inhibition

4. Non-competitive inhibition

5. Feedback inhibition

82. Feedback inhibition of enzyme action is affected by:

1. End products

2. Enzyme

3. Substrate

4. Allosteric inhibitor

5. None of these

83. How many polipeptide chains (subunits) contains molecule of creatine kinase?

1. Two

2. One

3. Three

4. Four

5. Six

84. Albinism is due to deficiency of the enzyme:

1. Phenylalanine hydroxylase

2. Tyrosinase

3. p-Hydroxyphenylpyruvic acid oxidase

4. Tyrosine dehydrogenase

5. Lactate dehydrogenase

85. Competitive inhibitor of succinate dehydrogenase is the next substance:

1. Malonate

2. Oxaloacetate

3. Alanine

4. Fumarate

5. α-Ketoglutarate

86. In rickets the next enzyme activity is highly elevated in blood serum:

1. Alkaline phosphatase

2. Lactate dehydrogenase

3. Aldolase

4. Alanyl aminotransferase

5. Amylase

87. The following statements describe coenzymes and prosthetic groups:

1. Some enzymes contain organic molecules that are derived from vitamins and that are essential for activity.

2. Some enzymes contain metal ions such as zinc or copper that are essential for their activity

3. Coenzymes are small polypeptides that are involved in transfer reactions catalysed by enzymes

4. Сoenzymes are required in some enzyme-catalysed reaction as carried of acyl groups or phosphate groups

5. Coenzymes are required in some enzyme-catalysed oxidation-reduction reactions involving hydrogen transfer