3rc bi exam Flashcards
- Which complex receives reducing equivalents
from the Citric Acid Cycle
A. Complex I
B. Complex II
C. Complex III
D. Complex IV
B
- Final common product of protein, carbohydrate
and fat metabolism
A. Citrate
B. Acetyl-CoA
C. Pyruvate
D. Glucose
B
- What is the final common pathway for the
metabolism of carbohydrates, proteins, and fats?
A. Citric Acid Cycle
B. Pentose Phosphate Pathway
C. Glycolysis
D. Glyconeogenesis
A
- This substrate is regenerated at the end of the
Citric Acid Cycle.
A. Oxaloacetate
B. Fumarate
C. Succinate
D. Citrate
A
- Which if the following enzymes link CAC to
gluconeogenesis?
A. Succinyl coA synthetase
B. Malate dehydrogenase
C. Pyruvate carboxykinase
D. Succinyl coA dehydrogenase
A
- Which of the following is the thermodynamically
favored structure presentation of glucose?
A. Haworth
B. Fischer
C. chair conformation
D. hemiacetal
D
- Total Number of ATPs produced in the Citric Acid
Cycle
a. 36
b. 10
c. 3
d. 38
B
- What is the vitamin that plays a key role as a
cofactor in CAC?
A. Vitamin A
B. Vitamin B
C. Vitamin C
D. Vitamin D
B
- GTP required in the decarboxylation of
Oxaloacetate to Phosphoenolpyruvate is provided in
this step
A. Oxaloacetate to Alpha-ketoglutarate
B. Succinate to Fumarate
C. Succinyl CoA to Succinate
D. Malate to Oxaloacetate
C
- ATP is produced in this step in Glycolysis
A. Glucose 6-Phosphate to
1,3-bisphosphoglyecerate
B. 1,3 bisphosphoglycerate to 3-phosphoglycerate
C. Glyceraldehyde 3-phosphate to
1,3-biphosphoglycerate
D. Glucose to Glucose 6-Phosphate
B
- NADH is formed in this step
A. Phosphoenolpyruvate to pyruvate
B. Glyceraldehyde 3-phosphate to
1,3-bisphosphoglycerate
C. Glucose to Glucose 6-phosphate
D. Glucose 6-phosphate to fructose 6-phosphate
B
- Which of the following is an irreversible step in
glycolysis?
A. Glucose to G6P
B. G6P to F6P
C. 1BPG to PEP
D. F1,6BP to G3
A
- Aldose-Ketose isomerization in glycolysis
A. Glucose to G6P
B. Phosphoenolpyruvate to pyruvate
C. Glucose-6-phosphate to
Fructose-6-phosphate
D. 2-phosphoglycerate to phosphoenolpyruvate
C
- Which is not a regulatory step in glycolysis?
A. Phosphofructokinase
B. Enolase
C. Hexokinase
D. Pyruvate kinase
B
NAD-dependent step in Glycolysis *
A. Glyceraldehyde 3-phosphate to
1,3-biphosphoglycerate
B. Glucose to Glucose 6-phosphate
C. Phosphoenolpyruvate to Pyruvate
D. Glucose 6-phosphate to Fructose
6-phosphate
A
- 2,3-DPG is an intermediate product in the
reaction catalyzed by?
A. Triose Phosphate isomerase
B. Enolase
C. Phosphoglycerate kinase
D. Phosphoglycerate mutase
D
- Alcohol inhibits absorption of this substance that
may cause potentially fatal pyruvic and lactic
acidosis:
A. Riboflavin
B. Thiamin
C. Pyruvate
D. Pantothenic Acid
B
- Glucose transporter in the liver
A. GLUT 2
B. GLUT 3
C. GLUT 1
D. GLUT 4
A
- What functions as a reserve to maintain the
blood glucose concentration in the fasting state?
A. Liver glycogen
B. Muscle glycogen
C. Both liver and muscle glycogen
D. Gluconeogenesis
A
- Inhibited by Phosphorylase Kinase A
A. Glycogen phosphorylase
B. Gluconeogenesis
C. Glycogenolysis
D. Glycogen synthase
D
- Which enzyme catalyzes the rate limiting step of
glycogenolysis?
A. Glucan transferase
B. Debranching enzyme
C. Glycogen synthase
D. Glycogen phosphorylase
D
- Inhibited by Phosphorylase Kinase A
A. Glycogen synthase
B. Glycogen phosphorylase
C. Glycogenolysis
D. Gluconeogenesis
A
- Activated by Phosphorylase Kinase A
A. Glycogen Phosphorylase
B. Glycogen Synthetase
C. Debranching Enzyme
D. Branching Enzyme
A
- What is the main source of NADPH in
lipogenesis?
A. Oxidative phosphorylation
B. Citric acid cycle
C. Pentose phosphate pathway
D. Glycolysis
C
- What is the enzyme for the deficiency of Von Gierke Disease?
A. Glucose-6-Phosphatase
B. Glucose-6-Phosphatase Dehydrogenase
C. Pyruvate Dehydrogenase
D. Aminotransferases
A
- Glucose transporter in the kidney?
A. GLUT 1
B. GLUT 2
C. GLUT 3
D. GLUT 4
D
27.Which of the following enzymes DOES NOT
prevent reversal of gluconeogenesis to glycolysis?
A. Pyruvate Kinase
B. Phosphofructokinase
C. Hexokinase
D. Enolase
D
- Oxaloacetate is converted to this substance for it
to be available for gluconeogenesis
A. Malate
B. Pyruvate
C. Citrate
D. Succinate
A
- What enzyme converts oxaloacetate to pyruvate?
A. Phosphoenolpyruvate carboxykinase
B. Pyruvate carboxylase
C. Succinate thiokinase
D. Pyruvate dehydrogenase
A
- Glucose-6-phosphate is transported to this
cellular organelle for removal of phosphate group
and release of free glucose?
A. Golgi apparatus
B. Mitochondria
C. Smooth ER
D. Rough ER
C
- Major precursor of glucose in ruminants
A. Glucose
B. Fructose
C. Propionate
D. Sucrose
C
- Which of the following is TRUE of the Pentose
Phosphate Pathway?
A. Lead to the formation of ATP
B. Synthesis of ribulose for nucleic acid
synthesis
C. Alternative route for the metabolism of
fructose
D. Formation of NADPH is one of its major
functions
D
- Gout occurs due to high levels of urate in the blood, also known as hyperuricemia. It is also related to the consumption of a certain disaccharide which can elevate urate levels.Which of the following is the disaccharide that can increase a person’s chances of developing gout?
A. Lactose
B. Sucrose
C. Glucose
D. Fructose
D
- Reducing sugar that can give false positive
results in Urinary Glucose measured through
Alkaline Copper reagents
A. Sorbitol
B. Xylulose
C. Xylose
D. Sucrose
B
- Most common genetic defect is secondary to a
mutation in this specific enzyme.
A. Pyruvate kinase
B. a-Ketoglutarate dehydrogenase
C. G6PD
D. Adenylyl cyclase
C
- Measurement of this erythrocyte enzyme is used
to assess the status of Vitamin B12 (The question
was B12 but it’s B2 jud)
A) Glutathione reductase
B) Glutathione synthase
C) Glucose-6-phosphate dehydrogenase
D) NADPH dehydrogenase
A
- Most severe form of galactosemia is manifested
secondary to the deficiency of this particular enzyme
A. Galactose dehydrogenase
B. Uridyl Transferase
C. Epimerase
D. Galactokinase
B
- The precursor of the sugar-phosphate moieties in
the de novo synthesis of both purine and pyrimidine
nucleotide
A. Ribose-1-phosphate
B. Glucose-1- phosphate
C. Ribose-5-phosphate
D. Glucose-6-phosphate
C
- Thermodynamically favored glucose structure
A. Hemiacetal
B. Fischer
C. Haworth projection
D. Chair configuration
A
- Which of the following is an essential amino
acid?
A. Methionine
B. Alanine
C. Proline
D. Tyrosine
A
- Which of the following is not a nutritionally
essential amino acid?
A. Valine
B. Phenylalanine
C. Glycine
D. Methionine
Some of the choices were modified
C
- Oxaloacetate undergoes transamination into
what amino acid?
A. Aspartate
B. Glutamate
C. Alanine
D. Glycine
A
- The formation of serine is from the oxidation of
the alpha hydroxyl group of this glycolytic
intermediate?
A. 3-phosphoglycerate
B. Oxaloacetate
C. Alpha ketoglutarate
D. L-homocysteine
A
- Which nutritionally essential amino acid donates
the sulfur group to the formation of cysteine?
A. Serine
B. Lysine
C. L-homocysteine
D. Methionine
D
- Which of the following is NOT a characteristic of
the amino acid tyrosine?
A. Tyrosine hydroxylase converts phenylalanine
to tyrosine
B. Nutritionally nonessential in the presence of
adequate phenylalanine
C. Reaction is irreversible
D. Tyrosine cannot replace phenylalanine
A
- Which is NOT TRUE to interorgan exchange?
A. Alanine is extracted primarily by the liver
B. The kidney provides a major source of Serine
C. Glutamine is extracted by both the gut and
the kidney
D. Branched Chain amino acids are released by
the muscles and taken by the gut.
D
- Which of the following is NOT a component of
the hydroxylation of peptidyl prolyl and peptidyl lysyl?
A. Ascorbate
B. Fe2+
C. Oxaloacetate
D. Molecule of O2
C
- Which is NOT true regarding transamination?
A. Reversible
B. Restricted to alpha amino acid
C. Occurs between pyruvate and alanine
D. Occurs mainly in the mitochondria
B
- The site of the urea cycle
A. Mitochondria
B. Cytosol
C. Mitochondria and Cytosol
D. None of the above
C
- The rate limiting step of urea cycle.
A. Carbamoyl phosphate synthetase I
B. Ornithine carbamoyltransferase
C. Argininosuccinate synthase
D. Argininosuccinate lyase
A
- The pacemaker enzyme of the urea cycle
E. Carbamoyl phosphate synthase I
F. Ornithine carbamoyl transferase
G. Argininosuccinate synthase
H. Argininosuccinate lyase
A
- Which of the following is an enzyme activator in
the urea cycle?
A. N-acetylglutamate
B. ADP
C. Mg-ATP
D. Ornithine
A
- Products formed in the cleavage of
argininosuccinate in the urea cycle
A. Arginase and Fumarate
B. Arginine and Succinate
C. Arginine and Fumarate
D. Arginine and Ornithine
C
- What is the enzyme defect that results in severe
ammonia intoxication?
A. Ornithine transcarbamoylase
B. Argininosuccinate synthetase
C. Argininosuccinate lyase
D. Arginase
A
- Incorrect statement with regards to the treatment
of all urea cycle disorders:
A. High protein diet
B. Lactulose
C. Antibiotics
D. Liver transplant
A
- Which of the following enters the citrate cycle via
the alpha-ketoglutarate intermediate?
A. Proline
B. Methionine
C. Phenylalanine
D. Serine
A
- The Amino acid that enters the Citric Acid Cycle
via succinyl coa.
A. Alanine
B. Methionine
C. Proline
D. Aspartate
B
- Which of the following statements is true about
proline?
A. Participates in transamination
B. Catabolism takes place in mitochondria
C. L-alpha nitrogen is immediately lost during
the first step of catabolism
D. Metabolic disorder is acquired
B
- Major role in allergic reactions
A. Alanine
B. Arginine
C. Histidine
D. Proline
C
- Which of the following is not a metabolic fate of
Arginine?
A. Spermine
B. Nitric oxide
C. Creatine
D. Fumarate
D
62.Which of the following participate in the
biosynthesis of coenzyme A?
A. Histidine
B. Cysteine
C. Glycine
D. Alanine
B
- Which of the following is the principal source of
all methyl groups in the body?
A. Methionine
B. S-adenosylmethionine
C. Cysteine
D. Glycine
B
- Participates in the biosynthesis of sphingosine,
purine, and pyrimidine
A. Serine
B. Glycine
C. Alanine
D. Methionine
A
- Participates in the biosynthesis of Serotonin
A. Serine
B. Glycine
C. Methionine
D. Tryptophan
D
- Which of the following is not a metabolic fate of
tyrosine?
A. DOPA
B. Nitric oxide
C. Epinephrine
D. Thyroid
B
- Which of the following provides the carbon
skeleton donor of selenocysteine?
A. Methionine
B. Arginine
C. Serine
D. Adenine
C
- Site of attachment of additional ubiquitin
A. C-terminus
B. N-terminus
C. Lys 48
D. Glycine 63
C
- The key gluconeogenic amino acid
A. Serine
B. Lysine
C. Arginine
D. Alanine
D
- Both a ketogenic and glucogenic amino acid
A. Methionine
B. Serine
C. Threonine
D. Phenylalanine
D
- Which of the following is not correct with the
statements regarding selenocysteine?
A. Biosynthesis requires serene, selenate, ATP,
and tRNA
B. Present in the active sites of several human
enzymes that catalyze redox reactions
C. Arises cotranslationally during its
incorporation into peptides
D. The AGA anticodon of the unusual tRNA
normally signals STOP
D
- What is the pacemaker enzyme of the urea
cycle?
A. Carbamoyl phosphate synthase I
B. Ornithine carbamoyl transferase
C. Argininosuccinate synthase
D. Argininosuccinate lyase
*choices are modified
A
- Biosynthesis of serine begins with what?
A. 3-phosphoglycerate
B. Dimethylglycine
C. Glutamate
D. Alpha-ketoglutarate
A
74.The interconversion from serine to glycine is
catalyzed by this enzyme.
A. Glycine hydroxymethyltransferase
B. Serine hydroxymethyltransferase
C. Glycine dehydrogenase
D. Serine dehydrogenase
B
- Which of the following is not a characteristic of
amino acid Tyrosine?
A. Tyrosine hydroxylase converts phenylalanine
to tyrosine
B. Nutritionally unessential in the presence of
adequate phenylalanine
C. Reaction is irreversible
D. Tyrosine cannot replace phenylalanine
A
- How do salvage reactions differ from other
synthesis pathways?
A. Salvage reactions convert purines and their
nucleosides to dinucleotides.
B. Phosphoryl transfer from PRPP requires
more energy expenditure.
C. These pathways synthesize nucleotides from
amino acids and glucose.
D. Salvage reactions require far less energy
than de novo synthesis.
D
- Formed by the reductive amidation of glutamate
to glutamine by the enzyme glutamine synthetase
A. β-glutamyl phosphate
B. γ-glutamyl phosphate
C. Glutamate dehydrogenase
D. Phosphoserine
B
- The clinical condition that is not a defect in purine
metabolism
A. Adenosine Deaminase deficiency
B. Lesch Nyhan syndrome
C. Gout
D. Chronic granulomatous disease
D
- A 55-year-old presents with an inflamed right big
toe and elevated uric acid levels. She was prescribed
allopurinol to manage her condition. What enzyme is
inhibited by this drug?
A. Xanthine oxidase
B. IMP dehydrogenase
C. PRPP synthase
D. HGPRTase
A
- The usual wavelength at which molecules that
contain purine or pyrimidine bases strongly absorb
Ultraviolet light:
A. 10 nm
B. 34 nm
C. 260 nm
D. 360 nm
C
- This property of DNA is the relationship between
bases in opposing strands in the double helix.
A. Anti-parallelism
B. Structural isomorphism
C. Complementarity
D. Degeneracy
C
- Most distinguishing feature of DNA from RNA
A. High purine content
B. The sugar backbone is ribose
C. Uses thymine instead of uracil
D. Consists of a single strand
C
- An 8 year old boy went to the hospital for
consultation. The doctor requested a laboratory
workup. The tests revealed deficiency in Adenine
deaminase enzyme and T-cells and B-cells. What
could be the possible diagnosis of this patient?
A. Lesch Nyhan Syndrome
B. von Gierke
C. Severe Combined Immunodeficiency Disease
D. Chronic Granulomatous Disease
C
- An antibiotic medication that can inhibit DNA
Gyrase
A. Cephalexin
B. Ceftriaxone
C. Ciprofloxacin
D. Sulfamethoxazole
C
- What enzyme converts Hypoxanthine to IMP?
A. Adenine phosphoribosyltransferase
B. Hypoxanthine-guanine
phosphoribosyltransferase
C. Xanthine Oxidase
D. Adenylosuccinate synthetase
B
- The type of DNA model by Watson and Crick
A. A-DNA
B. B-DNA
C. Z-DNA
D. C-DNA
B
- A left-handed zigzagging form of DNA with a helix pitch of 45.6
A. A-DNA
B. Z-DNA
C. B-BNA
D. C-DNA
B
- Which is not a STOP codon?
A. UAA
B. UAG
C. UCG
D. UGA
C
- What organ is the site of purine biosynthesis?
A. Kidney
B. Gut
C. Liver
D. Lungs
C
- What principle states that the concentration of
deoxyadenosine (A) nucleotide equals that of
thymidine (T) nucleotides (A=T), while the
concentration of deoxyguanosine (G) nucleotides
equals that of deoxycytidine (C) , nucleotides (C=G)
in DNA molecules?
A. Chargaff’s Rule
B. Anfinsen’s Dogma
C. Central Dogma
D. Genetic Code
A
- Which of the following processes does not
contribute to the purine nucleotide biosynthesis?
A. Synthesis from amphibolic intermediates
B. Phosphoribosylation of purines
C. Glutamine degradation
D. Phosphorylation of purine nucleosides
C
- Template for DNA synthesis
A. tRNA
B. rRNA
C. mRNA
D. Ribozymes
C
- This is the process where separated strands of
DNA will renature or reassociate when appropriate
physiologic temperature and salt conditions are
achieved.
A. DNA hybridization
B. Replication
C. Degeneracy
D. Okazaki fragmentation
*choices are modified
A
- This drug decreases the toxic effects of
methotrexate and pyrimethamine
A. Cyanocobalamin
B. Thiamine
C. Leucovorin (Folinic Acid)
D. Pyridoxine
C
- The enzyme that catalyzes the reaction that
controls the rate of purine de novo biosynthesis
A. PRPP synthase
B. Ribonucleotide Reductase
C. Thioredoxin Reductase
D. HGPRTase
A
- G6 phosphatase deficiency
A. Lesch Nyhan
B. Von Gierke disease
C. SCID
D. Orotic Aciduria
B
- Non-purine xanthine oxidase inhibitor
A. 5-FU
B. 6-mercaptopurine
C. Febuxostat
D. Allopurinol
C
- An organic solvent that destabilizes Hydrogen
bonding in nucleic acid structures and commonly
used in recombinant DNA experiments
A. 5-fluorouracil
B. Allopurinol
C. Formamide
D. 6-mercaptopurine
C
- Hypoxanthine is phosphorylated into Inosine
Monophosphate, by what enzyme?
A. PRPP synthetase
B. Hypoxanthine-guanine
phosphoribosyltransferase
C. Xanthine oxidase
D. Thymidylate synthase
B
Eighty percent (80%) of the brain’s energy is from glucose. The remaining 20% comes from which of the following sources?
a. ketone bodies
b. amino acids
c. fatty acids
d. other hexoses
A. Ketone Bodies
(Trans BIOCHEM3_35 -Glucoeneogenesis, p. 2)
Trytophan enters gluconeogenesis if it is converted into what substrate?
A Citrate
B. Succinyl-CoA
C. Alpha ketoglutarate
D. Pyruvate
Pyruvate
- Oxaloacetate will be converted to ______ for it to be available for Gluconeogenesis
A. Pyruvate
B. Malate
C. Citrate
D. Succinyl-CoA
B. Malate
Instead of becoming acetyl-coA, pyruvate becomes oxaloacetate (Mitochondria). It is catalyzed by pyruvate carboxylase
Oxaloacetate cannot get outside the mitochondria, thus Oxaloacetate becomes malate. Malate is then pushed out of the Mitochondria and is converted back to oxaloacetate.
(Trans 35 - Gluconeogenesis, p. 3)
Coenzyme of pyruvate carboxylase
Biotin
Glucose-6-Phosphate is transported to this cellular organelle in the liver for the removal of phosphate group and the release of free glucose.
A. Mitochondria
B. Smooth ER
C. Rough ER.
D. Golgi Apparatus
B. Smooth ER
Fatty acid enters gluconeogenesis via
A. DHAP
B. Lactate
C. Pyruvate
D. Fructose-1,6-bisphosphate
A. DHAP (?)
True of PPP
Lead to the formation of ATP
Alternative route for catabolism of carbohydrate
Formation of ribulose for nucleid acid synthesis
Formation of NADPH is one of its major functions
D (most likely)
Which of the following causes osmotic damage in diabetic cataract?
A. Fructose
B. Sucrose
C. Sorbitol
D. Glucose
C. Sorbitol
Which association is correct?
A. Glucagon inhibit gluconeogenesis in liver
B. Glucagon stimulate gluconeogenesis in liver
C. Epi and Norepi inhibit gluconeogenesis
D. Insulin stimulate gluconeogenesis
B. Glucagon stimulate gluconeogenesis in liver
This enzyme catalyzes the carboxylation and phosphorylation of Oxaloacetate to Phosphoenolpyruvate?
A. Phosphoenolpyruvate carboxykinase
B. Phosphoenolpyruvate kinase
C. Phosphoenolpyruvate oxidase
D. Phosphoenolpyruvate dehydrogenase
A. Phosphoenolpyruvate carboxykinase
Hyperuricemia leading to gout formation may be connected to the metabolism of of this specific sugar
A. Fructose
B. Sucrose
C. Glucose
D. Maltose
A. Fructose
Harper’s p.196
Most common genetic defect is secondary to amutation in this specific enzyme.
A. Pyruvate kinase
B. G6PD
C. a-Ketoglutarate dehydrogenase
D. Adenylyl cyclase
B. G6PD
The most severe form of galactosemia is secondary to the deficiency of what enzyme
A. Uridyl transferase
B. Epimerase
C. Galactose dehydrogenase
D. Galactokinase
C. Uridyl transferase
- Its presence determines whether glucose or glycogen can synthesize not only from pyruvate but also triose phosphates (glycerol)
a. Fructose-1,6-bisphosphatase
b. Fructose-6-phosphatase
c. Fructose-2,6-bisphosphatase
d. Fructose-1-phosphatase
A. Fructose-1,6-bisphosphatase
- Which enzyme is responsible for the phosphorylation of hexose sugars in extrahepatic tissues?
A. Hexokin-ase
B. Glucokinase
C. Fructokinase
D. Enolase
A. Hexokinase
Which of the following is a major component of seminal fluid?
A. Glucose
B. Fructose
C. Mannose
D. Galactose
B. Fructose
What enzyme is responsible for the carboxylation of pyruvate to oxaloacetate?
A. pyruvate carboxylase
B. pyruvate carboxykinase
C. pyruvate dehydrogenase
D. pyruvate oxidase
A. pyruvate carboxylase
what enzyme is responsible for the conversion of lactate to pyruvate?
a. LDH
b. MDH
c. pyruvate dehydrogenase
d. PEPCK
a. LDH - Lactate dehydrogenase converts lactate to pyruvate and vice versa.
Formation of Glucose from Glycogen is NOT PERMITTED in the muscle due to the absence of which enzyme?
A. Glycogen phosphorylase
B. Glucose-6-phosphatase
C. Glycogen synthase
D. Phosphoglucomutase
Glucose-6-phosphatase
What is the product of the transamination of pyruvate?
A. Proline
B. Alanine
C. Tyrosine
D. Alpha ketoglutarate
B. Alanine
Serine, alanine, cysteine, threonine, tryptophan, and glycine are all glucogenic amino acids that are substrates of what?
A. Acetyl-CoA
B. Succinyl-CoA
C. Pyruvate
D. Oxaloacetate
C. Pyruvate
Glucagon stimulates glycogenolysis in the liver by activating this enzyme
a. Glycogen phosphorylase
b. Glycogen synthase
c. Lactate dehydrogenase
d. Phosphoglucomutase
a. Glycogen phosphorylase
- Formation of this intermediate automatically ensures provision of oxaloacetate by activating pyruvate carboxylase
a. Pyruvate
b. Lactic acid
c. Acetyl CoA
d. Oxaloacetate
c. Acetyl CoA
The strongest stimulator of PFK-1 that stimulates glycolysis and inhibits gluconeogenesis
a. Xylulose-5-phosphate
b. Fructose 2,6-bisphosphate
c. Pyruvate
d. Oxaloacetate
B. Fructose 2,6-Bisphosphate
Which of the following enzyme activity is induced by insulin?
A. Pyruvate carboxylase
B. Phosphoenolpyruvate carboxykinase
C. Glucose 6-Phosphate
D. Phosphofructokinase-1
D. Phosphofructokinase-1
Characterized by profound hypoglycemia and vomiting after consumption of fructose or sucrose
A. Essential fructosuria
B. Hereditary fructose intolerance
C. Fructose induced Hypoglycemia
D. Essential Pentosuria
B. Hereditary fructose intolerance
This enzyme is responsible for the conversion of sorbitol to fructose
a. Sorbitol dehydrogenase
b. Sorbitol oxidase
c. Fructose dehydrogenase
d. Fructose oxidase
sorbitol dehydrogenase
Increased metabolism of this sugar increases fatty acid synthesis which increases TAG and LDL levels
A. Galactose
B. Fructose
C. Sucrose
D. Sorbitol
B. Fructose
Which of the ff can be used as index for Vit B1?
A. Erythrocyte Transketolase
B. Glucose-3-Phosphate
C. Fructose-6-Phosphate
D. Transaldolase
A. Eryth Transketolase
Which of the following is a byproduct of the irreversible oxidative phase of Pentose Phosphate Pathway?
A. Glucose 6-phosphate
B. 6-phosphogluconate
C. Glyceraldehyde 6-phosphate
D. NADPH
D. NADPH
- Oxidation by dehydrogenation in the PPP is done through what hydropegen acceptor?
A. NADP+
B. NAD
C. NADPH
D. NADH
A. NADP+
Alternative route of glucose metabolism that does not yield atp:
A. hmp shunt
B. cori cycle
A
Ratio: BioChem Trans: Lecture #34: PPP pg 1
Glycoproteins are classified based on which of the ff:
A. Based on the nature of the linkage between the polypeptide and the oligosaccharide chain
B. # of chains
D. Predominant amine
A. Based on the nature of the linkage between the polypeptide and the oligosaccharide chain
Binding to which lectin prevents a glycoprotein from aggregating?
A. Calnexin
B. Mannose-binding lectin
A. Calnexin
This is the non-enzymatic attachement of sugar (mainly glucose) to amino group of a protein (also other molecules such as DNA and lipid)
a. Glycosylation
b. Deglycosylation
c. Glycation
d. Maillard Reaction
c. Glycation
Harper’s 32nd ed. Ch. 46 p. 554 ebook version
N-acetylgalactosamine (GalNAc-Ser[Thr]) is what part of glycoprotein?
A. GPI
B. Collagen
C. Mucin
D. Proteoglycan
C. Mucin
Harper’s 32nd ed. Ch. 46 pp. 557-558
Matching Type: AGEs
Type 2 DM
Matching Type: Selectin
B. Leukocyte adhesion deficiency
Matching Type: ZP3
sperm receptor
Matching Type: PH30
D. Sperm Binding to Oocyte
Harper, p. 561
Matching Type: Decay Accelerating Factor
PNH
Matching Type: GP120
HIV
Matching Type: CD59
PNH
Matching Type: GP41
HIV
Matching Type: GPI
Helicobacter pylori
Nos. 46-50 Match the following linkages to the appropriate (glycoprotein?)
Asparagine-N-Acetylglucosamine Linkaage
N-linked
GAL-GAL-Xylene Trisaccharide-Serine
Proteoglycans
(PPT GLYCOPROTEINS.pptx, slide 8)
Galactose-hydroxy-LYSINE linkage
Collagen
(PPT GLYCOPROTEINS.pptx, slide 8)
Single N-acetyIglucosamine + SERINE or THREONINE residue
Nuclear and Cytosolic protein sidechains (NCPS)
(PPT GLYCOPROTEINS.pptx, slide 8)
N-acetylglucosamine + mannose and glucosamine
GPI linkage
Which of the following is a nutritionally non-essential amino acid?
A. Methionine
B. Valine
C. Lysine (modified bec forgot)
D. Alanine
D. Alanine
All other choices are nutritionally essential.
(Trans BIOCHEM3_37 Biosynthesis of Nutritionally Nonessential Amino Acids)
Which is not a characteristic of AA Glutamate?
A. Precursor of glutamate family
B. Reductive amidation using glutamate dehydrogenase to oxaloacetate
C. Glutamine using glutamine synthetase
D. y-glutamyl phosphate intermediate
B. Reductive amidation using glutamate dehydrogenase to oxaloacetate
The phrase “Reductive amidation using glutamate dehydrogenase to oxaloacetate” is incorrect because glutamate dehydrogenase does not act on oxaloacetate—it converts glutamate into α-ketoglutarate, not oxaloacetate.
Also see Harper’s p. 284
- What role does aspartate play in the Urea Cycle?
A. It donates a carbon atom
B. unrecalled
C. It acts as a substrate in the urea cycle
D. It helps in transport of nitrogen
C. It acts as a substrate in the urea cycle
Process of converting aspartate to oxaloacetate?
A. Transamination
B. Deamination
C. Decarboxylation
D. Hydrolysis
Transamination
What is the final product of serine metabolism that can enter the glycolytic pathway?
A. Pyruvate
B. Acetoacetyl-CoA
C. Fumarate
D. Citrate
A. Pyruvate
Which of the following is not a precursor of glycine biosynthesis?
A. Glyoxylate
B. Glutamate
C. Alanine
D. Cysteine
D. Cysteine
Enzyme responsible for conversion of phenylalanine to tyrosine
phenylalanine hydroxylase
dihydropterine hydroxylase
tyrosine hydroxylase
tryptophan hydroxylase
PAH
What cofactor is essential for enzyme phenylalanine hydroxylase to function properly
A. Niacin
B. Tetrahydrobiopterin (BH4)
C. Folic acid
D. Pyridoxal phosphate
B. Tetrahydrobiopterin (BH4)
Serine is also a precursor for what AA
a. cysteine
b. alanine
c. valine
d. methionine
Cysteine
What cofactor is required for the conversion of serine to glycine by serine hydroxymethyltransferase? A. NAD+ B. Tetrahydroxyfolate C. B12 D. Biotin
Tetrahydrofolate
Which of the following is the sulfur donor of cysteine
A. Glutamate
B. Phenylalanine
C. Methionine
D. Proline
Methionine
Harper’s pp. 277
What AA donates carbon skeleton to selenocysteine?
a. Lysine
b. Proline
c. Glutamine
d. Serine
Serine
Which toxic metabolite accumulates in PKU?
A. Homogentisic acid
B. Uric acid
C. Urocanic acid
D. Phenylpyruvate
Phenylpyruvic acid
Which is the common clinical feature for untreated PKU?
A. Malnutrition
B. Intellectual disability
C. Hyperpigmentation
D. Decreased muscle mass
Intellectual disability
What is the role of sapropterin in PKU treatment?
A. Serves as a replacement for the deficient phenylalanine hydroxylase
B. Acts as a cofactor for phenylalanine hydroxylase, enhancing the conversion of phenylalanine to tyrosine
C. Enhances the transport of phenylalanine across the blood-brain barrier
D. Reduces blood phenylalanine levels by increasing enzymatic activity in responsive individuals (nonverbatim)
B. Acts as a cofactor for phenylalanine hydroxylase, enhancing the conversion of phenylalanine to tyrosine
In intergorgan exchange, what is the role of glutamine as a substrate?
A. skeletal muscle
B. brain
C. liver
D. gut and kidney
Gut and kidney
After prolonged fasting, what would happen to muscle amino acid release
A. decrease due to muscle loss
B. increase for energy and homeostasis
C. remains unchanged
D. completeley stops
B. increase for energy and homeostasis
The following amino acids undergo transamination except
a. Lysine
b. Tyrosine
c. Leucine
d. cystine
Lysine
- Which of the following DOES NOT describe transamination
A. Reversible
B. Occurs mainly in mitochondria
C. Restricted to a-amino acids
D. Occurs between pyruvate and alanine
C. Restricted to a-amino acids
Where do the steps in the urea cycle take place?
A. mitochondria and cytosol
B. endoplasmic reticulum and ribosome
C. cytosol and golgi apparatus
D. nucleus and mitochondria
A. mitochondria and cytosol
Which of the following is the rate limiting enzyme in the Urea cycle?
A. Carbamoyl phosphate synthetase I
B. N-acetyl-glutamate synthetase
C. Ornithine transcarbamoylase
D. Argininosuccinate lyase
A. Carbamoyl phosphate synthetase I
An intermediate metabolite of the Urea Cycle that can enter the Krebs Cycle
a. Citrulline
b. Ornithine
c. Aspartate
d. Fumarate
Fumarate
Products formed by the cleavage of argininosuccinate in the urea cycle
a. L-arginine; Succinate
b. Arginase; Urea
c. L-arginine; Fumarate
d. Arginine; Ornithine
c: L-arginine; Fumarate
Incorrect statement with regards to the treatment of all urea cycle disorders:
A. High protein diet
B. Lactulose
C. Antibiotics
D. Liver transplant
High protein diet
Which of the following enters the citric acid cycle via the alpha-ketoglutarate pathway?
A. Proline
B. Tyrosine
C. Phenylalanine
D. Aspartate
A. Proline
Which of the ff enter the citric acid cycle via Succinyl-CoA intermediate in the glycogenic pathway?
A. Methionine
B. Arginine
C. Histidine
D. Asparagine
Methionine
Which of the following statements is true about proline?
A. Participates in transamination
B. Catabolism takes place in mitochondria
C. L-alpha nitrogen is immediately lost during the first step of catabolism
D. Metabolic disorder is acquired
B. Catabolism takes place in mitochondria
An AA that plays a major role in allergic reactions
a. Arginine
b. Alanine
c. Histidine
c. Histidine
Which of the ff is not a metabolic fate of arginine?
a. Nitric Oxide
b. Creatinine
c. Ornithine
d. Fumarate
D. Fumarate
Which of the ff participates in the biosynthesis of Coenzyme A?
a. Histidine
b. Cysteine
c. Glycine
d. Alanine
B. Cysteine
Principal source of methyl groups in the body?
a. Methionine
b. S-adenosylmethionine
c. Cysteine
d. Glutamine
SAM
ratio from Trans
What Amino Acid participates in the biosynthesis of sphingosine and of purines and pyrimidines?
A. Serine
B. Cysteine
C. Glycine
D. Arginine
Serine
Which of the following is an amino acid precursor of serotonin?
A. Tryptophan
B. Tyrosine
C. Glycine
D. Serine
Tryptophan
Which of the following is not a metabolic fate of tyrosine?
A. DOPA
B. Nitric Oxide
C. Epinephrine
D. Thyroxine
Nitric Oxide
Source of carbon skeleton of selenocysteine
A. Methionine
B. Cysteine
C. Thyroxine
D. Serine
Serine
Which of the following sites of attachment of ubiquitin in polyubiquitination?
A. C-terminus
B. N-terminus
C. Lysine 48
D. Glycine 63
C. Lysine 48
(Harper’s 32nd. Ch 28. p. 280)
It is the gluconeogenic key amino acid
A. serine
B. glycine
C. arginine
D. alanine
D. Alanine
what amino acid residue retards ubiquitine dependent degradation?
a. Met
b. Val
c. asp
d. arg
Met
What provides the major source of serine uptake for peripheral tissues?
a. brain
b. muscle
c. kidney
d. gut
c. kidney
which of the following about enzymes are incorrect with regards to transamination?
A. Pyridoxal phosphate (PLP), a derivative of vitamin B, is
present at the catalytic site of all aminotransferases, and plays
a key role in catalysis.
B. is Freely Reversible
C. Occurs via Pingpong Mechanism
D. Alpha amino acid restricted
Alpha amino acid restricted
Which of the following is not required for the synthesis of urea?
a. 5 enzymes
b. 1 mol of Ammonium ion
c. Arginine
d. 3 mols of ATP
Arginine
What is incorrect about urea formation?
A. Ammonia is the major end product of nitrogen catabolism in humans
B. N-acetylglutamate solely works as an eznyme activator
C. Reactions 1 and 2 occur in the liver mitochondria
D. Reactions 3, 4, and 5 occur in the liver cytosol
Ammonia is major end product in humans
Which of the following is INCORRECT with regards to urea synthesis
A. carbamoyl phosphate plus ornithine forms citrulline
B. citrulline plus aspartate forms argininosuccinate by the enzyme argininosuccinate decarboxylase
C. argininosuccinate cleavage forms fumarate and arginine
D. arginine cleaves to form urea and ornithine
citrulline plus aspartate forms argininosuccinate by the enzyme argininosuccinate decarboxylase
What symptom is not common to all metabolic disorder in the urea cycle.
A, Hyperammonemia
B. Avoidance of Carbs
C. Ataxia
D. Lethargy
B. Avoidance of Carbohydrate
(BIOCHEM3_38 pg. 8)
Hyperammonemia type I is due to the deficiency or inactivity of which enzyme?
A. Carbamoyl phosphate synthetase I
B. N acetylglutamate synthetase
C. Ornithine permease
D. Ornithine transcarbamoylase
A. Carbamoyl phosphate synthetase I
Which of the following is purely ketogenic
A. Alanine
B. Threonine
C. Tyrosine
D, Leucine
Leucine
Amphibolic intermediate of both glycogen and fat
Phenylalanine
Not a component of the glycine cleavage complex
A. three enzymes
B. H protein
C. dihydrolipoyl
D. ascorbate
D. Ascorbate
Which of the following conditions is associated with impaired transport of tryptophan and neutral amino acids in the intestine and kidneys?
a. MSUD
b. PKU
c. hartnup disease
d. Alkaptonuria
C. Hartnup disease
Which of the following is not true about tyrosine
A. Tyrosine hydroxylase converts phenylalanine to tyrosine
B. Nutritionally non-essential in the presence of adequate phenylalanine
C. Reaction is Irreversible
D. Tyrosine cannot replace phenylalanine
A. Tyrosine hydroxylase converts phenylalanine to tyrosine
Which of the following contributes atoms to the purine ring in de novo synthesis
a. ribose 5 phosphate
b prpp
c uric acid
d orotic acid
e THF
PRPP
✅ Weesafied
The initial reaction of pyrimidine de novo synthesis
A. PRPP attachment to pyrimidine
B. IMP formation
C. Reaction of Glutamine and CO2
D. UMP phosphorylation
E. Urate formation
C. Reaction of Glutamine and CO2
- Which of the following is the key difference bet de novo purine and pyrimidine synthesis?
A. Purine starts with a free base while pyrimidine synthesis starts after the ring is assembled
B. Purine starts after the ring is assembled, whereas pyrimidine builds the ring on PRPP
C. Purine catabolism forms highly water-soluble products, while pyrimidine catabolism forms insoluble products
D. Purine bla bla ions, pyrimidine
E. Pyrimidine is highly regulated, purine is not regulated
Not sure (wrong ang A, B, C, E & unrecalled ang D. abt ions to siya)
BONUS QUESTION ACC. DOC WEESA:
it was supposed to be “ in purine biosynthesis, PRPP serves as a scaffold for assembly of the purine ring, whereas PRPP participates in pyrimidine biosynthesis only subsequent to assembly of the pyrimidine ring”
First product in pyrimidine de novo synthesis?
A. Unrecalled
B. Unrecalled
C. OMP
D. UMP
E. TMP
C. OMP (?)
How do AMP and GMP regulate hepatic purine nucleotide biosynthesis?
A. They activate PRPP synthetase
B. They inhibit PRPP synthetase
C. They activate IMP dehydrogenase
D. They inhibit Xanthine oxidase
E. They stimulate the conversion UMP to UTP
B. They inhibit PRPP synthetase
In purine de novo synthesis, which of the following supplies the atoms of the purine ring?
A. Orotic Acid
B . Uric Acid
C. Hypoxanthine
D. PRPP
E. Glutamate
D. PRPP
Which of the following is involved in multiple steps in the de novo purine synthesis?
A. Vitamin B12
B. Vitamin C
C. Folate/folic acid
Folate/folic acid
In the de novo synthesis of pyrimidines, what is required for the atoms of pyrimidine ring?
A. Aspartate, glutamate, THF
B. Glycine, glutamate, THF
C. Asparate, glutamate, CO2
D. PRPP, glycine, THF
E. PRPP, glutamate, THF
C. Asparate, glutamate, CO2
How does the regulation of pyrimidine de novo synthesis primarily occur?
a. feedback inhibition of PRPP synthesis by AMP and GMP
b. Activation of carbamoyl phosphate synthetase II by PRPP
c. Feedback inhibition of aspartate transcarbamoylase (ATCase) by UTP and CTP
d. Activation of ribonucleotide reductase by dATP
e. Feedforward activation of thymidylate synthase by dUMP
B.
Which of the following is the first fully formed purine nucleotide in the de novo synthesis?
A. AMP
B. GMP
C. IMP
D. UMP
E. CMP
Inosine monophosphate (IMP)
What role does PRPP have on purine and pyrimidine nucleotide de novo synthesis?
A. Provides the nitrogenous base
B. Inhibits rate limiting enzyme
C. Serves as an activated sugar intermediate
D. Directly forms phosphodiester bond
E. Cofactor for ribonucleotide reductase
C. Serves as an activated sugar intermediate
Idk asa ni sa book nakaindicate T_T pero check this link:
https://accesspharmacy.mhmedical.com/content.aspx?bookid=3231§ionid=269372172
Which of the ff is unique to pyrimidine synthesis as compared to purine?
A. Stepwise addition of base in ribose phosphate
B. Purine adds PRPP after the ring has been formed, while pyrimidine builds the ring on PRPP
C. Requires PRPP as an initiating committed step
D. More complex and uses more ATP
E. By-product is uric acid
A. Stepwise addition of base in ribose phosphate
Based on this image in ratio, B, C, D, E can be eliminated
13.Main differences between purine and pyrimidine catabolism
Purine catabolism produces water soluble compounds pyrimidine catabolism produces water insoluble
Pyrimidine catabolism produces water soluble compounds purine catabolism produces water insoluble /
Purines produce urates pyrimidines produce ammonia
Pyrimidines produces nucleotides purines produce nucleosides
Purines produce deoxyribonucleotides pyrimidines produce ribonucleotides
B. Pyrimidine catabolism produces water soluble compounds. purine catabolism produces water insoluble
What is the significance of the “salvage pathway” in nucleotide metabolism?
A. Essential for de novo nucleotide synthesis
B. Irrelevant in cells with active purine degradation
C. Used in the conversion (“recycling”) of purines, their ribonucleosides, and their deoxyribonucleosides into mononucleotides
D. Exclusively occurs in mitochondria
(modified choices)
C.
What enzyme converts xanthine into hypoxanthine in the salvage pathway of purine biosynthesis?
A. ADA – Adenosine Deaminase
B. HGPRT – Hypoxanthine-Guanine Phosphoribosyltransferase
C. XO – Xanthine Oxidase
D. RR – Ribonucleotide Reductase
B. HGPRT – Phosphoribosyltransferase
Importance of Purine Salvage Pathways
A. The brain has low levels of PRPP glutamyl amidotransferase therefore salvage pathway is important
B. Erythrocytes low levels of PRPP they don’t need salvage pathway
C. Important to synthesize Uridine
D. Important to synthesize Cytidine
A. The brain has low levels of PRPP glutamyl amidotransferase therefore salvage pathway is important
Aside from phosphoribosylation of prpp what is another salvage mechanism?
A. deamination then hydroxylation
B. phosphorylation of adenosine kinase
C. oxidation by xanthine oxidase
D. reduction by ribonucleotide reductase
E. methylation by methyltransferases
B. phosphorylation of adenosine kinase
A child is brought to the pediatrician with recurrent infections. Physical examination reveals absent tonsils. Laboratory tests show a profound decrease in both T and B lymphocyte counts. What is the condition?
A) Wiskott-Aldrich Syndrome
B) X-linked Agammaglobulinemia
C) Severe Combined Immunodeficiency (SCID)
D) DiGeorge Syndrome
some choices revised
Severe combined immunodeficiency
A 7 yr old exhibits self-mutilation, behavioral problem, and developmental delays. Which of the following is likely elevated in their urine?
A. Aspartate
B. Hypoxanthine
C. I forgot :((
D. Uric Acid
D. Uric Acid
Lesch-nyhan syndrome results from the deficiency of which enzyme?
a. thymidilate synthase
b. hypoxanthine-guanine phosphoribosyl transferase
c. xanthine oxidase
d. ribonucleotide reductase
e. thymine kinase
b. hypoxanthine-guanine phosphoribosyl transferase
Administration of allopurinol, but with normal HGPRT level. Which of the following will it lead to:
A. Decrease PRPP synthase
B. Decrease blood xanthine levels
C. Increase de novo synthesis of IMP
D. Increase hypoxanthine in the urine
E. Increase urate crystals
D. Increase hypoxanthine in the urine
✅ Weesafied
A 6 month old boy began to show signs of deteriorating motor skills and severe megaloblastic anemia. His urine contains fine needle crystals identified as orotic acid. Oral administration of which compound would likely result in significant clinical improvement?
a. Adenosine
b. Cytidine
c. Guanosine
d. Thymidine
e. Uridine
e. Uridine
✅ Weesafied
A patient presents with orotic aciduria, but without megaloblastic anemia, and UMP synthetase activity is normal. What enzyme is likely deficient in this condition?
a. aspartate transcarbamoylase
b. ornithine transcarbamoylase
c. thymidine synthase
d.orotidine 5’-phosphate carboxylase
b. ornithine transcarbamoylase
A 10yo boy is undergoing chemotheraphy for acute myelogenous leukemia. He experiences fever, flank pain, pain in ankles, and blood in urine. An increased catabolism of this compound explains his condition.
a. amino acid
b. fatty acid
c. purine
d. pyrimidine
e. vitamin C
C. Purine
Which of the following laboratory findings is most characteristic of a mutation in ornithine transcarbamylase (OTC)?
A. Increased argininosuccinate levels
B. Elevated serum orotic acid
C. Decreased urinary orotic acid
D. Hyperammonemia with normal orotic acid levels
B. Elevated serum orotic acid
Which best describes the underlying cause of gout?
A. Development of calcium pyrophosphate dihydrate crystals
B. Autoimmune attack on joint cartilage
C. Excessive production or reduced excretion of uric acid leading to the formation of urate crystals
D. Bacterial infection in the synovial fluid
C. Excessive production or reduced excretion of uric acid leading to the formation of urate crystals
Defining characteristic between gout and pseudogout
a. They are caused by the same crystal deposition
b. Gout is as as moth eaten in radiograph while pseudogout is as Martel Sign
c. Gout is caused by uric acid crystal deposition while pseudo gout is caused by calcium pyrophosphate deposition.
d. Gout is caused by deficiency in HGPRT enzyme while Pseudogout is caused overproduction of HGPRT enzyme
c. Gout is caused by uric acid crystal deposition while pseudo gout is caused by calcium pyrophosphate deposition.
Xanthine oxidase inhibitor that lowers uric acid.
A. Azothioprine
B.5-fluorouracil
C.Allopurinol
D. Mycophenolic acid
C. Allopurinol
Which of the following is used during organ transplantation tos suppress immunologic reaction?
A. 6-mercaptopurine
B. 5-fluorouracil
C. Azathioprine
D. Mycophenolic acid
C. Azathioprine
Which of the following statements about 5-fluorouracil is CORRECT?
A. It inhibits ribonucleotide reductase
B. It promotes normal cell growth and replication
C. It is a purine analog used to treat hyperuricemia and gout
D. It is a pyrimidine analog that acts as a suicide substrate to inhibit thymidylate synthase
D. It is a pyrimidine analog that acts as a suicide substrate to inhibit thymidylate synthase.
- A drug that inhibits the conversion of dihydrofolate to tetrahydrofolate would most directly affect the synthesis of?
A. Fatty Acid
B. Amino Acid
C. Purine nucleotides
D. Pyrimidine catabolism
Not sure: purine nucleotides?? Pyrimidine catabolism means breakdown
True of methotrexate:
A) Analog of glutamate
B) Inhibits thymidylate synthase
C) Directly increases purine synthesis
D) Inhibits dihydrofolate reductase (DHFR)
D. Inhibits DHFR
An 8-year-old patient with recurrent infections due to a deficient enzyme in the purine salvage pathway. Which of the following enzymes are affected?
A. Adenine deaminase
B. HGPRT
C. Xanthine oxidase
D. Ribonucleotide Reductase
Not sure: HGPRT
Which enzyme converts uric acid into the more water-soluble product allantoin?
A. Xanthine oxidase
B. HGPRT
C. Uricase
D. Adenine deaminase
C. Uricase
What is the primary mechanisms of action of the chemotherapeutic drug 6-mercaptopurine?
a. inhibits dihydrofolate reductase
b. interfers with purine nucleotide biosynthesis
c. directly damage DNA by alkylation
d. prevents formation of mitotic spindle
B. Interfers with purine nucleotide biosynthesis
What bond connects the nucleotides in the polynucleotide chain of the nucleic acids?
A. Peptide bond
B. Glycosidic bond
C. Phosphodiester bond
D. Hydrogen bond
C. Phosphodiester bond
Which of the following is responsible for the ability of a nucleotide to be detected in spectrophotometry?
A. Their ability to fluoresce under UV light
B. Their resonance energy transfer (not sure about this)
C. Their size and molecular weight
D. Their conjugated double bond system absorbs UV light
D. Their conjugated double bond system absorbs UV light
Correct base pairing in DNA?
a. A to G
b. A to C
c. A to T
d. A to U
C. A to T
What is the use of the enzyme reverse transcriptase?
a. degrade RNA molecule
b. Cut the DNA sequence
c. synthesize DNA from RNA template
d. ligate DNA synthesis
c. synthesize DNA from RNA template
What structural component defines a nucleoside
A. A pyrine or pyrimidine base, ribose sugar, and a phosphate group
B. A purine or pyrimidine base only
C. A ribose sugar and a phosphate group
D. A purine and pyrimidine base and a ribose sugar no phosphate group
D. A purine and pyrimidine base and a ribose sugar no phosphate group
What is the physiological form of DNA?
A. A-DNA
B. B-DNA
C. E-DNA
D. Z-DNA
B. B-DNA
Which of the following has a role in mRNA splicing?
A. mRNA
B. tRNA
C. rRNA
D. snRNA
D. snRNA
What structural feature is unique to eukaryotic mRNA?
A. 3’ cap
B. 5’ cap (7-methylguanosine)
C. unrecalled
D. Base uracil
5’ cap (7-methylguanosine)
Restriction endonuclease
A. Dna from RNA template
B. Ligate DNA fragments together
C. Cleave DNA at specific sequence
D. Million folds
E. Place phosphate at 5’ end of nucleic acid
C. Cleave DNA at specific sequence
The polymerase chain reaction (PCR) is a technique used to:
A. Analyze protein structure
B. Amplify specific DNA sequences
C. Detect RNA molecules
D. Cleave DNA at specific sites
E. Analyze lipid composition
B. Amplify specific DNA sequences
Which of the following is true about the Southern blot technique?
A. It allows the analysis of a specific DNA fragment
B. It allows the analysis of a specific RNA fragment
C. It allows the analysis of proteins
D. It is used for DNA amplification
E. It is used for separation by isoelectric points
A. It allows the analysis of specific DNA sequences
RNAi is primarily used in cells to:
A. Promote the degradation of specific mRNA molecules, regulating gene expression
B. Enhance translation of mRNA into proteins
C. Repair damaged DNA in the cell nucleus
D. Assist in the replication of viral RNA
A. Promote the degradation of specific mRNA molecules, regulating gene expression
RNA interference (RNAi) is a therapeutic approach that is useful for treating diseases where:
A. there is a deficiency in an essential protein
B. there is a mutation in tumor suppressor gene
C. there is chromosomal deletion
D. expression of the abberant or mutant protein is the cause of the symptoms
E. there is a need for emplication of a specific DNA sequence
D. expression of the abberant or mutant protein is the cause of the symptoms
DNA fingerprinting is (non-verbatim)
A. an amplification of DNA fragments
B. an analytical technique that uses repeat sequences to establish a unique pattern of fragments for individuals
C. altering the genetic material of an organism
D. a method to verify the identity of clones fragments
(other choices are just filled-in from the ppt coz I can’t remember sorry)
an analytical technique that uses repeat sequences to establish a unique pattern of fragments for individuals
Molecular cloning
A. Process of amplifying DNA from a complex mixture without prior isolation
B. Cleave DNA at nonspecific location
C. (Unrecalled)
D. allows for the production of a large number of identical DNA molecules, usually uses bacterial host
E. Something about RNA
D. allows for the production of a large number of identical DNA molecules, usually uses bacterial host
An information of the flow of genetic information characterized by replication of DNA, transcription of DNA to RNA, and the sequence of RNA being translated into a protein sequence at the ribosomes.
A. Chargaff’s Rule
B. Anfinsen’s dogma
C. Central Dogma of Molecular Biology
D. First Law of Thermodynamics
C. Central Dogma of Molecular Biology
What is the role of tRNA as an adaptor molecule?
A. Carry the nucleotides for amino acids to be synthesized
B. Hold the promoter region in place for polymerase recognition
C. Recognize the codons via the anticodon arm
D. Synthesize amino acids
C. Recognize the codons via the anticodon arm
Which of the following is the template in RNA-directed protein synthesis.
A. mRNA
B. tRNA
C. rRNA
D. snRNA
Question is modified, i think there was some mention of “DNA” in the question but it was confusing huhu. Doc just emphasized that the “template” is mRNA.
A. mRNA
The meaning of Degeneracy of the Genetic Code
A. An amino acid can only be decoded by a single codon
B. A single codon encodes only one amino acid
C. Multiple codons may encode the same amino acid
D. With time, codons degenerate into senseless code
C. Multiple codons may encode the same amino acid
This mineral is a cofactor of glutathione and a helps guard against DNA damage
A. Copper
B. Manganese
C. Selenium
D. Zinc
C. Selenium
To specifically identify the DNA mutation in a cancer patient, what blotting technique should be used
A. Northern
B. Southern
C. Southwestern
D. Western
B. Southern
Basis for using taq polymerase for pcr
facilitate annealing of proteins
is resistant to heat denaturation
promotes DNA polymerization
provide optimum condition for DNA synthesis
Resistant to heat denaturation
Inactive and always condense chromatin usually found near chromosomal centromere and chromosomal telomeres
A. Constructive heterochromatin
B. Constructive euchromatin
C. Transcriptional euchromatin
D. Histones
A. Constructive heterochromatin
DNA replication machinery serves to edit or proofread most recently added deoxynucleotide for base-pairing errors
a. DNA ligase
b. DNA topoisomerase 1
c. 3’-5’ exonuclease
d. Endonucleases
C.
Specific enzymes capable of cleaving internal phosphodiester bonds.
A. Endonucleases
B. Ribonucleoproteins
C. 3’ - 5’ Exonucleases
D. Restriction nucleases
A. Endonucleases
The type of RNA that has a cloverleaf appearance and an anticodon arm
A. mRNA
B. tRNA
C. rRNA
D. Ribonucleosome
B. tRNA
Harper’s Ch. 34 pp. 355
This structure is involved in the recognition of mRNA by the translation machinery and prevent mRNA from nucleolytic attack by 5-exoribonucleases.
A. Poly-A tail
B. 5-Methylguanosine cap
C. Anticodon arm
D. Acceptor arm
B. 5-Methylguanosine cap
Which of the following is not a stop sequence?
A. UAA
B. UAC
C. UGA
D. UAG
B. UAC
Which amino acid is encoded by the start codon?
A. Glutamic acid
B. Valine
C. Cysteine
D. Methionine
D. Methionine
In cancer, what type of mutation typically results in the premature termination of an amino acid squence?
A. Frame shift mutation
B. Silent mutation
C. Missense mutation
D. Nonsense mutation
D. Nonsense mutation
A patient has leukemia. She was given a drug that activate hsp 90. What drug is it?
A. Puromycin
B. Oligomycin
C. Geldanamycin
D. Rifampicin
C. Geldanamycin✅
Which of the following is NOT a disease of proteostasis
deficiency of a disease due to misfolding of proteins?
A. Huntington’s Disease
B. Myotonic Disorder
C. Alzheimer’s Disease
D. Parkinson’s Disease
B. Myotonic Disorder
The protein is used in vesicles destined for and in sp those carrying cargo to lysosomes?
A. Clathrin
B. SNARE protein
C. Synaptobrevin
D. Synaptophysin
A. clathrin
An ATP-dependent major pathway of protein degradation.
A. Lysosomal proteases
B. Brefeldin
C. Ubiquitin
D. Proteosome
C. Ubiquitin
A year old child presented with coarse facial features, poor muscle tone, and skeletal abnormalities. What enzyme is deficient is this child with I-cell or inclusion disease?
a. beta glucosidase
b. alpha 1 anti-trypsin
c. beta hexosaminidase
d. 1-phosphotransperase
d. 1-phosphotransperase
A 44-year-old African American man presents with splenomegaly and anemia. A laboratory workup reveals a substitution of valine for glutamic acid at the sixth position of the β-globin chain. What is the most likely diagnosis?
A. Beta-thalassemia
B. Sickle Cell Disease
C. Hereditary Spherocytosis
D. Autoimmune Hemolytic Anemia
B. Sickle Cell Disease
A small piece of DNA that inserts itself into another place within genome
a. Indel
b. Exon
c. Intron
d. Transposons
d. Transposon
The structural analog that actively inhibits protein synthesis in both prokaryotes and eukaryotes.
a. Tetracycline
b. Puromycin
c. Cycloheximide
d. Ricin
b. puromycin
The field of gene regulation that states that regulatory mechanisms do not change the underlying regulated DNA sequence, but
rather simply the expression patterns, or function, of this DNA.
a. molecular biology
b. biotechnology
c. genetic testing
d. epigenetics
d. epigenetics
This is considered to be the smallest unit of genetic expression:
A. Intron
B. Exon
C. Chaperone
D. Cistron
D. Cistron
A single mRNA that encodes more than one separated protein:
A. Polycistronic mRNA
B. Messenger RNA
C. Topoisomerase II
D. Template RNA
A. Polycistronic mRNA
What feature characterizes the DNA damage due to radiation?
A. Formation of apurinic and apyrimidic sites due to elimination of corresponding bases
B. Formation of pyrimidinic dimer
C. Double and single strand breakage and crosslinkage
D. AOTA
D. AOTA
A cluster of genes working under one promoter and one operator
A. cistron
B. operon
C. TATA Box
D. exon
B. operon
Protein that helps other proteins avoid misfolding and
production of reactive or aggregated species. Also called heat
shock proteins.
A. BEG gene
B. Mutagen
C. Chaperone
D. Cistron
C. Chaperone
The mushroom poison amanitin is an inhibitor of the synthesis of:
A. DNA
B. Messenger RNA
C. Glycoxalyx
D. Protein
B. Messenger RNA
MOST ABUNDANT EUKARYOTIC RNA.
A. Ribosomal RNA
B. Small non-coding tRNA
C. Small nuclear RNA
D. MicroRNA (miRNA) and short interfering RNA (siRNA)
A. Ribosomal RNA
Main enzyme involved in mainly involved in transcription
a. ligase
b. helicase
c. rna polymerase
d. topoisomerase II
C. RNA polymerase
The strand that is transcribed or copied into an RNA molecule? A. Lagging strand B. Template strand C. Leading strand D. Okazaki fragments
B. Template Strand
The form of RNA polymerase that is highly sensitive to alpha-amanitin.
A. RNA polymerase I
B. RNA polymerase II
C. RNA polymerase III
D. RNA polymerase IV
B. RNA polymerase II
Sequence that interupts the coding region of protein-encoding gene
a. Intron
b. Extron
c. Cistron
d. Polycistron
a. Intron
The trinucleotide repeat characteristic of Huntington’s Disease
A. CTG
B. CAG
C. CGG
D. GAA
B. CAG
The property of a genetic code that says for any specific codon, a single amino acid is specified
A. Unambiguous
B. Universal
C. Degenerate
D. Non overlapping, without punctuations
A. Unambiguous
Which does not play a role in protein folding?
a. PDI
b. chaperone
c. opsonin
d. PPI
c. opsonin
a structural analog of tyrosinyl-tRNA effectively inhibits protein synthesis in both prokaryotes snd eukaryotes
a. tetracycline
b. puromycin
c. cycloheximide
d. ricin
b. puromycin
What disease is characterized by the accumulation of very long chain fatty acids and accumulation of phytanic acids
A. Neonatal Adrenoleukodystrophy
B. Von Willebrand’s Disease (idt this was the one sa choices but nakalimut na ko guys sorryy)
C. Refsum’s Disease
D. Zellweger’s Syndrome
C. Refsum’s Disease
Catalase and urate oxidase are marker enzymes for this organelle:
A. Peroxisome
B. Mitochondria
C. Lysosome
D. Golgi apparatus
A. Peroxisome
As telomerase activity declines with age, telomeres shorten and are associated with cell senesence and premature aging is seen in which disease:
A. Refsum’s disease
B. Zellwegger’s
C. Adrenoleukodystrophy
D. Progeria
D. Progeria
This enzyme is responsible for the formation of swivels by DNA polymerase and unwinding of DNA.
A. DNA Topoisomerase I
B. DNA Topoisomerase II
C. Helicase
D. DNA Ligase
C. Helicase
Protien Toxin from this bacteria catalyze ADP Ribosylation and inactivation of Elongation Factor 2 (EF 2)
A. Clostridium botulinum
B. Clostridium perfringes
C. Corynebacterium Diptharea
D. Staphylococcus aerus
C. Corynebacterium Diptharea
A toxic inhibitor found in castor beans that catalyzes the cleavage of eukaryotic large subunit rRNA
A. Fusidic acid
B. Ricin
C. Cycloheximide
D. Puromycin
B. Ricin
Which enzyme joins the leading and lagging strands together (Okazaki fragments)?
A. Topoisomerase I
B. Topoisomerase II
C. Helicase
D. Ligase
D. Ligase
eukaryotic DNA polymerase that plays a role in DNA proofreading and repair?
A. DNA polymerase I
B. DNA polymerase II
C. DNA polymerase III
D. DNA primase
B. DNA polymerase II
A 25-year-old woman was diagnosed with a urinary tract infection and was given a drug that inhibits DNA gyrase. What was this drug?
A. Ceftriaxone
B. Ciprofloxacin
C. Piperacillin
D. Trimethoprim
B. Ciprofloxacin
Which of the following sources of DNA damage is not associated with chain breaks?
A. UV light induced thymine-thymine (pyrimidine) dimer
B. Ionizing radiation
C. Radioactive disintegration of backbone element
D. Oxidative free-radical formation
A. UV light induced thymine-thymine (pyrimidine) dimer
Defects in nucleotide excision repair (NER) are associated with which genetic disorder?
A. Colorectal cancer
B. SCID
C. Xeroderma pigmentosum
D. Lesch-Nyhan syndrome
C. Xeroderma pigmentosum
