Biochemistry Multiple Choice Questions on “Feeder Pathways for Glycolysis”.
1. The deficiency of which of the following enzyme leads to galactosemia?
A. Galactokinase
B. Pyruvate kinase
C. PFK-1
D. PFK-2
Answer: A
Clarification: In galactokinase deficiency galactosemia, high galactose concentrations are found in blood and urine.
2. The conversion of which of the following involves two nucleotide derivatives?
A. Galactose 1-phosphate to glucose 1-phosphate
B. Galactose 1-phosphate to fructose 1-phosphate
C. Fructose 1-phosphate to glucose 1-phosphate
D. Lactose 1-phosphate to glucose 1-phosphate
Answer: A
Clarification: The conversion of galactose 1-phosphate to glucose 1-phosphate involves two nucleotide derivatives: UDP-galactose and UDP-glucose.
3. Which of the following enzyme is responsible for the conversion of glucose 1-phosphate to glucose 6-phosphate?
A. Glycogen phosphorylase
B. Isomerase
C. Phosphoglucomutase
D. Epimerase
Answer: C
Clarification: Phosphoglucomutase converts the glucose 1-phosphate to glucose 6-phosphate, which can enter glycolysis.
4. Which product is formed in the isomerization of mannose 6-phosphate?
A. Fructose 6-phosphate
B. Glucose 6-phosphate
C. 2-phosphoglycerate
D. 3-phosphoglycerate
Answer: A
Clarification: Mannose 6-phosphate is isomerized by phosphomannose isomerase to yield fructose 6-phosphate.
5. Which of the following enzyme is present in saliva?
A. Hexokinase
B. Alpha amylase
C. Fructokinase
D. Triose kinase
Answer: B
Clarification: Digestion begins in the mouth, where salivary alpha amylase hydrolyses starch to sucrose.
6. Which of the following conversions is not catalyzed by hexokinase?
A. D-Glucose to glucose 6-phosphate
B. D-Fructose to fructose 6-phosphate
C. D-Mannose to mannose 6-phosphate
D. D-Fructose to fructose 1-phosphate
Answer: D
Clarification: Conversion of D-Fructose to fructose 1-phosphate is catalyzed by fructokinase.
7. Hydrolysis of lactose yields ___________
A. D-galactose and D-glucose
B. D-glucose and D-glucose
C. D-galactose and D-fructose
D. D-fructose and D-glucose
Answer: A
Clarification: Hydrolysis of lactose yields D-galactose and D-glucose.
8. Hydrolysis of sucrose yields ___________
A. D-galactose and D-glucose
B. D-glucose and D-glucose
C. D-galactose and D-fructose
D. D-fructose and D-glucose
Answer: D
Clarification: Hydrolysis of sucrose yields D-fructose and D-glucose.
9. Maltose hydrolysis yields ___________
A. D-galactose and D-glucose
B. 2-D-glucose
C. n-D-glucose
D. 2-D-fructose
Answer: B
Clarification: Maltose hydrolysis yields 2-D-glucose.
10. Dextrin hydrolysis yields ___________
A. D-galactose and D-glucose
B. 2-D-glucose
C. n-D-glucose
D. 2-D-fructose
Answer: C
Clarification: Dextrin hydrolysis yields n-D-glucose.
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