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Essential Biochemistry - Hemoglobin Metabolism (Section 1)

1
Which of the following conditions is characterized by deficiency in the conjugation of bilirubin?
Answer
(B)
Gilbert's syndrome
2
What is the name of the enzyme responsible for adding iron to the protoporphyrin ring?
Answer
(B)
Ferrochelatase
3
Which enzyme catalyzes the formation of porphobilinogen?
Answer
(D)
Porphobilinogen deaminase
4
Name the types of jaundice?
Answer
A
B
C
5
What is the term for jaundice caused by an increased breakdown of red blood cells?
Answer
(C)
Hemolytic jaundice
6
What is the role of albumin in bilirubin metabolism?
Answer
(B)
Transports bilirubin in blood
7
In obstructive jaundice, what would you expect to find?
Answer
A
B
C
8
In the liver, bilirubin is conjugated with
Answer
(B)
Glucuronic acid
9
Unconjugated bilirubin is raised mostly in:
Answer
(A)
Hemolytic jaundice
10
What is the first step in heme synthesis?
Answer
(A)
Condensation of glycine and succinyl CoA
11
In which disease is the excretion of bilirubin into the bile impaired?
Answer
(C)
Dubin-Johnson syndrome
12
Where is bilirubin conjugated?
Answer
(A)
Liver
13
Which of the following are the symptoms of acute intermittent porphyria?
Answer
A
B
14
The normal concentration of serum bilirubin is?
Answer
(A)
0.1 to 0.4 mg/dL
15
What is the role of Uridine diphosphate glucuronosyltransferase (UGT) in bilirubin metabolism?
Answer
(A)
Bilirubin conjugation
16
Which of the following is a characteristic of Crigler-Najjar syndrome?
Answer
(B)
Deficiency in UDP-glucuronosyltransferase
17
Which of the following is NOT a step in bilirubin excretion?
Answer
(D)
Conversion to heme
18
What is the fate of urobilinogen?
Answer
(D)
All of the above
19
Which is a characteristic feature of Dubin-Johnson syndrome?
Answer
(B)
Darkly pigmented liver
20
What is the name of the enzyme that catalyzes the rate-limiting step in heme synthesis?
Answer
(A)
ALA synthase
21
Which type of jaundice is associated with an obstruction of the bile duct?
Answer
(C)
Obstructive
22
What is the most common inherited cause of unconjugated hyperbilirubinemia?
Answer
(B)
Gilbert's syndrome
23
What is the characteristic of bilirubin diglucuronide?
Answer
(A)
Water-soluble
24
What is the role of glucuronic acid in bilirubin metabolism?
Answer
(A)
To make bilirubin water-soluble
25
What is the main site of bilirubin conjugation?
Answer
(A)
Liver
26
Which step in heme synthesis requires the enzyme ferrochelatase?
Answer
(C)
Insertion of iron into protoporphyrin IX
27
Which of the following is NOT a cause of hyperbilirubinemia?
Answer
(D)
Increased red blood cell production
28
What is the main source of bilirubin?
Answer
(A)
Hemoglobin breakdown
29
Which of the following enzymes is deficient in the Crigler-Najjar syndrome?
Answer
(A)
UDP-glucuronosyl transferase
30
Which is the cause of Jaundice?
Answer
(A)
High amounts of bilirubin in blood
31
Which one is the end product of catabolism of heme?
Answer
(A)
Bilirubin
32
Which of the following is a feature of obstructive jaundice?
Answer
(A)
Increased direct bilirubin
33
The first step in the biosynthesis of porphyrins is the condensation of glycine and succinyl-CoA to form
Answer
(B)
δ-aminolevulinate
34
What is the significance of the indirect bilirubin test?
Answer
(B)
Measures unconjugated bilirubin
35
What is the most common cause of unconjugated hyperbilirubinemia?
Answer
(B)
Gilbert syndrome
36
What is the main biochemical features of the hepatic jaundice?
Answer
A
C
D
37
Which of the following is not involved in bilirubin metabolism?
Answer
(D)
Secretion of bilirubin into blood
38
Which type of jaundice would present with dark urine and pale stools?
Answer
(B)
Obstructive jaundice
39
Which of the following is a characteristic feature of obstructive jaundice?
Answer
(C)
Clay-colored stools
40
What is the cause of jaundice when bilirubin exceeds 1 mg/dL?
Answer
(A)
Hyperbilirubinemia
41
Where does heme synthesis occur?
Answer
(A)
Mitochondria and cytoplasm
42
What is the primary function of bilirubin in the body?
Answer
(B)
Waste product
43
What are the normal symptoms of Porphyria?
Answer
A
B
C
44
Which of the following conditions is associated with an increased amount of unconjugated bilirubin?
Answer
(D)
Gilbert's syndrome
45
What is the primary function of heme?
Answer
(A)
Oxygen transport
46
What is the cause of physiologic jaundice in newborns?
Answer
(B)
Immature liver function
47
What is the cause of Dubin-Johnson syndrome?
Answer
(C)
Defective bilirubin excretion into bile
48
What is the precursor to Urobilinogen in intestine?
Answer
(B)
Bilirubin diglucuronide
49
What causes the brown color of feces?
Answer
(C)
Stercobilin
50
What is the main component of gallstones?
Answer
(B)
Cholesterol