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Essential Biochemistry - Carbohydrate Metabolism (Section 5)

1
Which molecule acts as an allosteric activator of glycogenolysis?
Answer
(B)
AMP
2
What is the role of the debranching enzyme?
Answer
(C)
To remove branches and release free glucose.
3
What is the main effect of glucagon in glucose metabolism?
Answer
(B)
Increases glycogenolysis
4
Which of the following is a symptom commonly associated with diabetes mellitus?
Answer
(C)
Polyuria
5
What is the primary function of the Cori cycle?
Answer
(C)
To recycle lactate from muscle to glucose in the liver
6
Which molecule initiates the citric acid cycle?
Answer
(B)
Acetyl-CoA
7
Which of the following is/are characteristic of Von Gierke's disease?
Answer
A
B
C
D
8
Which of the following enzymes are regulated by phosphorylation?
Answer
(D)
All of the above
9
Which of the following enzymes is inhibited by ATP?
Answer
(C)
Phosphofructokinase-1
10
The enzyme primarily responsible for the formation of branches in glycogen is:
Answer
(C)
Branching enzyme
11
What would be the typical blood glucose level to diagnose diabetes?
Answer
(C)
Fasting blood glucose ≥126 mg/dL
12
Which of the following is the precursor for UDP-glucose?
Answer
(A)
Glucose-1-phosphate
13
Which enzyme is most directly involved in gluconeogenesis?
Answer
(C)
Glucose-6-phosphatase
14
Which of the following best describes the role of NADPH in the pentose phosphate pathway?
Answer
(C)
Reducing power for biosynthesis and protection against oxidative stress
15
What is the characteristic clinical finding in individuals with essential fructosuria?
Answer
(B)
Fructose in the urine
16
What is the name of the pathway that helps form UDP-glucose?
Answer
(D)
Galactogenesis
17
Which of the following best describes the role of glycogen synthase?
Answer
(C)
To add glucose residues to a growing glycogen chain
18
Which of the following enzymes catalyzes the conversion of oxaloacetate to phosphoenolpyruvate?
Answer
(B)
Phosphoenolpyruvate carboxykinase
19
Which of the following best describes the role of the branching enzyme in glycogen metabolism?
Answer
(B)
Forms α-1,6-glycosidic bonds
20
Which of the following statements are correct regarding the role of insulin?
Answer
A
B
C
21
Which enzyme is responsible for the activation of glycogen phosphorylase in muscle?
Answer
(B)
Phosphorylase kinase
22
How does insulin regulate blood glucose levels?
Answer
(C)
Increases glucose uptake
23
Which of the following is the primary function of the pentose phosphate pathway?
Answer
(B)
Production of NADPH and precursors for nucleotide biosynthesis
24
In diabetes, what is the primary cause of hyperglycemia?
Answer
(B)
Decreased insulin sensitivity
25
Which of the following is true about the regulation of glycogenolysis?
Answer
B
C
26
What is the primary product of the catabolism of fructose?
Answer
(B)
Glyceraldehyde 3-phosphate and dihydroxyacetone phosphate
27
What is the end product of the anaerobic glycolysis in muscle cells?
Answer
(C)
Lactate
28
Which of the following is an allosteric activator of glycogen phosphorylase in muscle?
Answer
(C)
AMP
29
Which enzyme is deficient in individuals with essential fructosuria?
Answer
(A)
Fructokinase
30
Where does fructose metabolism primarily occur?
Answer
(A)
Liver
31
In which cellular location does glycogen synthesis primarily occur?
Answer
(A)
Cytosol
32
Which of the following is/are involved in the regulation of glycolysis?
Answer
A
B
C
33
What is the primary function of glycogenolysis?
Answer
(B)
To break down glycogen into glucose.
34
Which enzyme is responsible for the conversion of glucose to glucose-6-phosphate?
Answer
(B)
Hexokinase
35
Which of the following enzymes are crucial in the regulation of blood glucose?
Answer
A
B
D
36
Which of the following is a characteristic of GLUT4?
Answer
(B)
It is insulin-dependent.
37
Which of the following is a sign of diabetes mellitus?
Answer
(B)
Polyuria
38
What is the role of fructose-2,6-bisphosphate (F-2,6-BP) in carbohydrate metabolism?
Answer
(A)
Activates phosphofructokinase-1
39
What is the primary site for fructose metabolism in the body?
Answer
(A)
Liver
40
What are the main functions of glycogen in the body?
Answer
A
B
41
In the pentose phosphate pathway, the primary purpose of generating NADPH is for:
Answer
(B)
Fatty acid synthesis and protection against oxidative stress
42
Which of the following molecules can be used as a substrate for gluconeogenesis?
Answer
A
B
C
43
Essential fructosuria is caused by a deficiency in:
Answer
(A)
Fructokinase
44
What is the fate of pyruvate in anaerobic conditions?
Answer
(C)
It is converted to lactate.
45
In which part of the cell does glycolysis take place?
Answer
(B)
Cytoplasm
46
In which organ does fructose metabolism primarily occur?
Answer
(A)
Liver
47
Which of the following is TRUE about the pentose phosphate pathway?
Answer
A
C
48
The pentose phosphate pathway occurs mainly in:
Answer
(B)
Liver and adipose tissue
49
Which condition is linked to a deficiency in glucose-6-phosphate dehydrogenase (G6PD)?
Answer
(B)
Hemolytic anemia
50
Which step of glycolysis is irreversible?
Answer
(D)
All of the above