3rd Biochemistry Lecture Exam (Batch 2026) Flashcards
1.The mechanism of action of toxicity of carbon monoxide is:
a.Binds to Cytochrome C Oxidase which results in impairment of NADPH synthesis
b.Reduced carrying capacity of hemoglobin for Oxygen through the formation of carboxyhemoglobin
c.Carbon monoxide alters the configuration of hemoqlobin lessening its affinity for oxygen
d.Carbon Plonoxide is a competitive inhibitor of oxygen
b.Reduced carrying capacity of hemoglobin for Oxygen through the formation of carboxyhemoglobin
4.A four allele deletion will result in ,
a.Fetal hydrops
b.Asymptomatic
c.Cooley‘s Anemia
d.jaundice
a.Fetal hydrops
5.First indicator of thalassemia
a.Low hemoglobin, Low hematocrit
b.Low Hemoglobin, Low WBC
c.Low NCV, Low hematocrit
d.Low MCV, Low hemoglobin
d.Low MCV, Low hemoglobin
6.Indicative of Thalassemia in peripheral blood smear
a.Nicrocytic cells
b.Normochromic cells
c.Anisocytosis
d.Decreased percentage of reticulocytes
c.Anisocytosis
7.Which of the following statements is true regarding the ABO blood system?
a.People who have the A antigen normally would not produce the anti-A antibody
b.People who have the AB antigen normally would produce both anti-A and B antibodies
c.The only ABO type blood that normally does not have either A or B antigens is AB
d.None of the above
a.People who have the A antigen normally would not produce the anti-A antibody
8.ABOi kidney transplantation is made possible because of
a.Desensitization protocols
b.Rituximab
c.Recombinant endo-B-gaIactosidase
d.Eculizimab
a.Desensitization protocols
9.The disadvantage of plasma exchange as an antibody depletion strategy is
a.Loss of albumin
b.Loss of coagulation factors
c.Loss of anti-viral immunoglobulin
d.All of the above
d.All of the above
10.The replacement of ABO antigens that are compatible to the donated client to make ABOi kidney transplant possible is
a.Due to the presence of CD55 and CD59
b.Humoral immunity
c.Tolerance in ABO specific B cell elimination in the young
d.Endothelial Chimerism
d.Endothelial Chimerism
11.Presence of carbon monoxide poisoning results to which of the following?
A.Shifting of the oxygen dissociation curve to the left
B.Shifting of the oxygen dissociation curve to the right
C.Causes an increased delivery of oxygen to tissues
D.Decreases the oxygen affinity of the remaining 3 oxygen-binding sites
A.Shifting of the oxygen dissociation curve to the left
12.Which can be omitted in managing patients with Thalassemia and other hemoglobinopathies?
A.Iron supplements
B.Folic Acid supplements
C.Blood transfusions
D.Chelation
A.Iron supplements
13.This accounts for the largest fraction of total hemoglobin (90%):
A.HbA
B.HbF
C.HbA2
D. HbAlc
A.HbA
14.What happens to the oxygen dissociation curve of an anemic patient?
A.There is a “shift to the left” with associated reduction of the affinity of hemoglobin to oxygen
B.There is a “shift to the left” with associated increase of the affinity of hemoglobin to oxygen
C.There is a “shift to the right” with associated reduction of the affinity of hemoglobin to oxygen
D.There is a “shift to the right” with associated increase of the affinity of hemoglobin to oxygen
C.There is a “shift to the right” with associated reduction of the affinity of hemoglobin to oxygen
15.Which of the following Red Cell Indices show the differences in the sizes of Red Blood Cells?
A.Nean Corpuscular Volume
B.Red Cell Distribution Width
C.Mean Corpuscular Hemoglobin
D.Mean Corpuscular Hemoglobin Concentration
B.Red Cell Distribution Width
16.Which statement is true regarding management of patients with carbon monoxide poisoning?
A.Oxygen is the most important treatment and is always indicated for at least 6 hours
B.Oxygen toxicity is likely with less than 24 hours of treatment.
C.Currently, the evidence for any treatment beyond 100% oxygen is very strong
D.All are correct
A.Oxygen is the most important treatment and is always indicated for at least 6 hours
17.Which beta thalassemia syndrome is characterized by frequent transfusions, marked
hepatosplenomegaly, craniofacial changes, and stunting of growth:
A.Thalassemia intermedia
B.Thalassemia major
C.Silent carrier
D.Thalassemia trait
B.Thalassemia major
18.This hemoglobin is markedly elevated in Beta thalassemia major:
A.Hb A1
B.Hb A2
C.Hb F
D.Hb H
C.Hb F
19.Currently, the only cure available to patients with sickle cell disease
A.Crizanlizumab
B.Stem Cell Transplantation
C.Hydroxyurea
D.Gene therapy
B.Stem Cell Transplantation
20.The mode of inheritance of Beta thalassemia major is:
A.Autosomal dominant
B.Autosomal recessive
C.X-linked recessive
D.De novo mutation
B.Autosomal recessive
21.Which amino acid is commonly formed in many transamination reactions?
A.Alanine
B.Aspartate
C.Glutamate
D.Lysine
C.Glutamate
22.The intermediates named are generated from Cysteine, EXCEPT?
A.taurine
B.mercaptoethanolamine
C.melanin
D.pyruvate
C.melanin
23.Which of the following amino acids is NOT a donor of one carbon compound?
A.Histidine
B.Tyrosine
C.Tryptophan
D.Serine
B.Tyrosine
24.In mammalian cells, Ser can be a biosynthetic substrate for the synthesis of what amino acid?
A.Nethionine
B.Lysine
C.Arginine
D.Glycine
D.Glycine
25.Which coenzyme is used by serine hydroxymethyltransferase acting on Serine?
A. N5N10 methylene tetrahydrofolate
B. Tetrahydrofolate
C. Formyl tetrahydrofolate
D. Methyl tetrahydrofolate
B.Tetrahydrofolate
26.Dioxyphenylakanine is synthesized from which of the amino acids named:
A.Tyrosine
B.Tryptophan
C.Histidine
D.Nethionine
A.Tyrosine
27.Which is the coenzyme and its precursor used in transamination reactions?
A.NAD+/vitamin B3
B.FAD/vitamin B2
C.pyridoxal PO4/vitamin B6
D.cobalamin/vitamin B12
C.pyridoxal PO4/vitamin B6
28.Why is Histidine classified as a glucogenic amino acid?
A.it‘s degraded to a-ketoglutarate
B.upon its breakdown it gives rise to acetyl CoA
C.a product of its oxidation is pyruvate
D.it produces alanine
A.it‘s degraded to a-ketoglutarate
29.What is the defect in a child with non-classic PKU?
A.deficiency of phenylalanine hydroxylase
B.a lack of dihydrobiopterin reductase
C.a defect on tyrosine transaminase
D.a mutated fumarylacetoacetate hydrolase
B.a lack of dihydrobiopterin reductase
30.Which is the most common pair used in transamination reaction?
A.a ketoglutarate/glutamate pair
B.pyruvate/alanine pair
C.oxaloacetate/aspartate pair
D.a ketobutyrate/malate pair
A.a ketoglutarate/glutamate pair
31.Food products containing which of the following are advised not to be consumed by persons with classic type of PKU?
A.Oleomarqarine
B.Crisco
C.Sprye
D.Aspartame
D.Aspartame
32.If an amino acid upon degradation of its carbons generates aceoacety CoA and fumarate, it is classified as:
A.glucogenic amino acid
B.ketogenic amino acid
C.both glucogenic/ketogenic amino acid
D.essential amino acid
C.both glucogenic/ketogenic amino acid
33.Which amino acid whose carbons upon degradation gives rise to acetoacetate:
A.Leucine
B.Serine
C.Asparagine
D.Methionine
A.Leucine
34.Which metabolic abnormality gives rise to the serious disease phenylketonuria?
A.Homocysteine cannot be converted into methionine
B.Phenylalanine cannot be converted into tyrosine
C.Phenylalanine cannot be converted into alanine
D.Tyrosine cannot be converted into phenylalanine
B.Phenylalanine cannot be converted into tyrosine
35.In Naple Syrup Urine Disease, the enzyme deficient is:
A.a-keto acid dehydrogenase
B.branched-chain amino acid transaminase
C.§-methyIcrotonyI CoA dehydrogenase
D.enoyl CoA hydratase
A.a-keto acid dehydrogenase
36.Which is the disease brought about by a mutation affecting the gene that codes for the enzyme homogentisic acid oxidase?
A.tyrosinemia type I
B.Richner-Hanhart syndrome
C.tyrosinemia type II
D.alkaptonuria
D.alkaptonuria
37.Which causes Tyrosinemia Type I?
A.fumarylacetoacetate hydrolase deficiency
B.lack of phenylalanine hydrolase
C.absence of cystathionine §-synthase
D.defect in homogentisate oxidase structure
A.fumarylacetoacetate hydrolase deficiency
38.Which amino acid is used to synthesize Adomet?
A.Cys
B.Met
C.Ser
D.Ala
B.Met
39.Which is the fate of the sulfate generated In the metabolism of cysteine?
A.incorporated into other substrates
B.liberated unchanged
C.used in the synthesis of PAPS
D.incorporated into glucose to form cerebrosides
C.used in the synthesis of PAPS
40.Which is substrate of nitric oxide synthase (NOS) generating NO, an endothelial relaxing factor?
A.Asn
B.Lys
C.Asp
D.Arg
D.Arg
41.Which reaction converts Histidine to Histamine during an allergic reaction?
A.decarboxylation
B.reduction
C.oxidation
D.hydroxylation
A.decarboxylation