#1
Which molecule is the primary energy currency of the cell?
ATP
ExplanationATP is used as energy currency in cellular processes.
#2
What is the rate-limiting enzyme in the de novo synthesis of fatty acids?
Acetyl-CoA carboxylase
ExplanationAcetyl-CoA carboxylase catalyzes the committed step in fatty acid synthesis.
#3
What is the role of biotin in cellular metabolism?
Cofactor for enzymes involved in fatty acid synthesis
ExplanationBiotin serves as a cofactor for carboxylation reactions in fatty acid synthesis.
#4
What is the primary function of the enzyme catalase in cells?
Detoxification of hydrogen peroxide
ExplanationCatalase catalyzes the decomposition of hydrogen peroxide.
#5
In glycolysis, which enzyme catalyzes the conversion of 3-phosphoglycerate to 2-phosphoglycerate?
Phosphoglycerate mutase
ExplanationPhosphoglycerate mutase catalyzes the conversion of 3-phosphoglycerate to 2-phosphoglycerate in glycolysis.
#6
What is the first step in glycolysis?
Glucose phosphorylation
ExplanationGlucose is phosphorylated to glucose-6-phosphate.
#7
Which enzyme is responsible for breaking down glycogen to glucose in glycogenolysis?
Glycogen phosphorylase
ExplanationGlycogen phosphorylase catalyzes glycogen breakdown.
#8
Which vitamin is essential for the synthesis of collagen in the body?
Vitamin C
ExplanationVitamin C is required for collagen synthesis.
#9
What is the primary function of the electron transport chain in cellular respiration?
ATP synthesis
ExplanationThe electron transport chain generates ATP through oxidative phosphorylation.
#10
Which of the following is an essential amino acid?
Leucine
ExplanationLeucine is an essential amino acid that must be obtained from the diet.
#11
During anaerobic glycolysis, what is the fate of pyruvate?
Converted to lactate
ExplanationPyruvate is converted to lactate in anaerobic conditions.
#12
In which cellular compartment does the Krebs cycle occur?
Mitochondria
ExplanationThe Krebs cycle occurs in the mitochondrial matrix.
#13
Which of the following is a product of the pentose phosphate pathway?
Ribose-5-phosphate
ExplanationRibose-5-phosphate is a product of the pentose phosphate pathway.
#14
In gluconeogenesis, which enzyme catalyzes the conversion of pyruvate to phosphoenolpyruvate?
Phosphoenolpyruvate carboxykinase
ExplanationPhosphoenolpyruvate carboxykinase converts pyruvate to phosphoenolpyruvate in gluconeogenesis.
#15
Which of the following is a key regulatory enzyme in the citric acid cycle (Krebs cycle)?
Isocitrate dehydrogenase
ExplanationIsocitrate dehydrogenase regulates the rate of the Krebs cycle.
#16
Which enzyme is responsible for converting ribonucleotides to deoxyribonucleotides in DNA synthesis?
Thymidylate synthase
ExplanationThymidylate synthase converts ribonucleotides to deoxyribonucleotides in DNA synthesis.
#17
In which phase of the cell cycle does DNA replication occur?
S phase
ExplanationDNA replication occurs during the S phase of the cell cycle.