55. Which enzyme is regulated by feedback inhibition from ATP?
A) Hexokinase
B) Phosphofructokinase-1
C) Pyruvate kinase
D) Enolase
56. Under anaerobic conditions, pyruvate is converted to lactate by which enzyme?
A) Pyruvate kinase
B) Lactate dehydrogenase
C) Pyruvate dehydrogenase
D) Aldolase
57. Which step in glycolysis produces NADH?
A) Glucose to Glucose-6-phosphate
B) Glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate
C) 1,3-bisphosphoglycerate to 3-phosphoglycerate
D) Phosphoenolpyruvate to Pyruvate
58. The primary function of glycolysis in skeletal muscle is to:
A) Produce NADPH
B) Generate ATP
C) Synthesize glycogen
D) Produce lactate
59. Which hormone stimulates glycolysis in the liver?
A) Glucagon
B) Insulin
C) Epinephrine
D) Cortisol
60. Which molecule inhibits pyruvate dehydrogenase by allosteric regulation?
A) AMP
B) Acetyl-CoA
C) Fructose-2,6-bisphosphate
D) ADP
61. Which coenzyme is a prosthetic group of pyruvate dehydrogenase?
A) NAD+
B) FAD
C) Thiamine pyrophosphate (TPP)
D) Biotin
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62. Which glycolytic intermediate is also a precursor for nucleotide synthesis?
A) Glucose-6-phosphate
B) Fructose-1,6-bisphosphate
C) Pyruvate
D) Dihydroxyacetone phosphate
63. Which enzyme catalyzes the reversible conversion of glucose-6-phosphate to
fructose-6-phosphate?
A) Hexokinase
B) Glucose-6-phosphate isomerase
C) Phosphofructokinase-1
D) Enolase
64. During fasting, which pathway is enhanced to produce glucose?
A) Glycolysis
B) Gluconeogenesis
C) Pentose phosphate pathway
D) Beta-oxidation
65. The shift of the oxygen dissociation curve to the right is facilitated by:
A) 1,3-Bisphosphoglycerate
B) 2,3-Bisphosphoglycerate
C) NADH
D) Fructose-6-phosphate
66. Which molecule is a key activator of pyruvate kinase?
A) ATP
B) Fructose-1,6-bisphosphate
C) Citrate
D) NAD+
67. In glycolysis, which enzyme catalyzes the first ATP-producing step?
A) Hexokinase
B) Phosphoglycerate kinase
C) Pyruvate kinase
D) Enolase
68. In the regulation of glycolysis, glucagon inhibits which enzyme?
A) Hexokinase
B) Phosphofructokinase-1
C) Pyruvate kinase
D) Glucose-6-phosphate isomerase
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69. Which glycolytic enzyme is induced by insulin?
A) Pyruvate kinase
B) Phosphofructokinase-1
C) Hexokinase
D) Glucokinase
70. Which coenzyme is involved in the oxidative decarboxylation of pyruvate?
A) NADPH
B) NADH
C) NAD+
D) FAD
71. Which intermediate of glycolysis participates in the pentose phosphate pathway?
A) Fructose-6-phosphate
B) Glucose-6-phosphate
C) Pyruvate
D) Dihydroxyacetone phosphate
72. Which enzyme catalyzes the last step of glycolysis?
A) Pyruvate kinase
B) Lactate dehydrogenase
C) Enolase
D) Phosphoglycerate kinase
73. Where does the pyruvate dehydrogenase (PDH) complex reaction occur?
A) Cytosol
B) Mitochondrial matrix
C) Endoplasmic reticulum
D) Nucleus
74. What type of reaction is catalysed by the pyruvate dehydrogenase complex?
A) Hydrolysis
B) Oxidative decarboxylation
C) Reductive carboxylation
D) Transamination
75. Which coenzyme is derived from vitamin B1 (thiamine)?
A) FAD
B) NAD+
C) TPP
D) Coenzyme A
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76. What is the clinical manifestation of thiamine deficiency?
A) Pellagra
B) Beriberi
C) Scurvy
D) Rickets
77. Which component of the PDH complex transfers acetyl groups to CoA?
A) E1: Pyruvate dehydrogenase
B) E2: Dihydrolipoyl transacetylase
C) E3: Dihydrolipoyl dehydrogenase
D) Citrate synthase
78. What is the irreversible product of the PDH reaction?
A) Lactate
B) Acetyl-CoA
C) Oxaloacetate
D) Alpha-ketoglutarate
79. Which molecule inhibits the PDH complex?
A) AMP
B) Acetyl-CoA
C) ADP
D) Pyruvate
80. Which vitamin deficiency is associated with Pellagra?
A) Vitamin B1
B) Vitamin B2
C) Vitamin B3
D) Vitamin B5
81. The PDH complex is activated by which of the following?
A) High ATP levels
B) Acetyl-CoA
C) High AMP levels
D) High NADH levels
82. Which vitamin deficiency can lead to neurological disturbances due to the inhibition
of PDH?
A) Vitamin A
B) Vitamin D
C) Vitamin B1 (Thiamine)
D) Vitamin E
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