Download classsssssss

• The genetic evaluation of a family with hereditary
anemia reveals a point mutartion in th e beta –globin
gene, which results in the replacement of guanine by
cytosine in the beta-globin mRNA molecule three bases
upstream from the AUG codon (postion 6)
• A. trnaslocation during traanslation
• B. peptide bond formation
• C. mRNA binding to ribosomes
• D. terminaition of polypeptide synthesis
• E. protein targeting
• An infant born to a22-year-old female
experiences lethargy, vomiting and jaundice
soon after birth. The infant is placed on a
galactose-free formula and shows gradual
improvement. Which of the following steps in
galactose metabolism is most likely impaired
in this patient?
• An RNA molecule isolated from a culture of grampositive bacteria consists of 90 nucleotides and
contains both dihydrouracil and acetylcytosine
residues. Which of the following is the most likely
composition of the 3’ end of this molecule?
• A. TATA
• B. CCA
• C. poly-A
• D. AUG
• E. methyguanosine triphosphate
• F. UAG
• During starvation, the
liver oxidizes fatty acids
produces glucose for
peripheral tissues. The
product of which of the
following reactions is
used as a phosphate
source for
phosphoenolpyruvate
in gluconeogenesis?
• A comatose laboratory technician is rushed into the
emergency room. She dies while you are examining her.
Her most dramatic symptom is that her body is literally hot
to your touch, indicating an extremely high fever. You learn
that her lab has been working on metabolic inhibitors and
that there is a high likelihood that she accidentally ingested
one. Which one of the following is the most likely culprit?
•
• Barbiturates
• Piericidin A
• Dimercaprol
• Dinitrophenol
• Cyanide
•
• The protein rich in basic amino acids, which
functions in the packaging of DNA in
chromosomes, is:
• Histone
• Collagen
• Hyaluronic acid binding protein
• Fibrinogen
• All of the above
• HMP shunt is of great importance in cellular
metabolism because it produces
• A. ATP
• B. Acetyl CoA
• C. ADP
• D. NADPH
• During gluconeogenesis reducing equivalents
from mitochondria to the cytosol are
transported by
• A. Malate
• B. Aspartate
• C. Glutamate
• D. Oxaloacetate
• E. None of the above
• Two weeks after an episode of the flu, an 8-year-old
boy with IDDM is brought to the emergency room in
coma. His breathing is rapid and deep, and his breath
has a fruity odor. His blood glucose is 36.5 mM
(normal: 4-6 mM; 70-110 mg/dL). The physician
administers IV fluids, insulin, potassium chloride. A
rapid effect of insulin in this situation is to stimulate
• Gluconeogenesis in the liver
• Fatty acid release from adipose
• Ketone utilization in the brain
• Glucose transport in muscle
• Glycogenolysis in the liver
• An infant suffering from lethargy and vomiting is
diagnosed with a deficiency of several mitochondrial
enzymes. A common subunit containing lipoic acid is
abnormal in these enzymes. The patient is most likely
to have which of the following findings?
• A. citrullinemia
• B. Methylmalonic aciduria
• C. homocystinuria
• D. orotic aciduria
• E. lactic acidosis
• Red blood cells from a 24-year-old African American
male who suffers from periodic hemolysis demonstrate
a low activity of glucose-6-phosphate dehydrogenase.
Deficiency of which of the following erythrocyte
enzymes has the same pathophysiology as this
patient’s condition?
• A. bisphosphoglycerate mutase
• B. pyruvate kinase
• C. hexokinase
• D. transketolase
• E . glutathione reductase
• Liver cells that demonstrate a high concentration
of fructose 2,6-bisphosphate have a low rate of
which of the following conversions?
• a. glucose → glycogen
• b. acetyl CoA → fatty acids
• c. pyruvate → oxaloacetate
• d. alanine → glucose
• e. none of the above
• At low blood glucose concentrations, brain, but
not liver will take up glucose. This is due to the:
•
• Low KM of Hexokinase
• Low KM of Glucokinase
• Presence of insulin
• Blood Brain Barrier
• Specificity of Glucokinase
• A patient that is diagnosed as having Von Gierke’s
Disease is likely to exhibit which one of the
following symptoms?
•
• Enlarged Liver
• Elevated Blood pH
• Hyperglycemia
• Hypolipidemia
• Hypouricemia
• A 24yr medical student becomes depressed after his
girlfriend for four years broke up with him. He drank a
cleaning agent that has arsenate as its active
ingredient. The effect that arsenate will have on the
body is?
•
• A. Inhibit electron flow in the electron transport chain
• B. Activate ATP synthase
• C. Prevent ATP and NADH Production by Glycolysis
• D. Prevent the catabolism of Brach chain Amino Acids
• E. All of the above
• Muscle phosphorylase is deficient in which of
the following glycogen storage disorder?
•
• Cori’s Disease
• Von Gierke Disease
• Mc Ardle’S Disease
• Pompe’s Disease
• Anderson’s Disease
• Chronic granulomatous disease characterized by
severe persistent infection and granulomas is a
result of a deficiency of which of the following?
•
• G-6-P Dehydrogenase
• NADPH Oxidase
• NO synthase
• Protein Kinase
• Superoxide dismutase
• What are the regions of mRNA called that
code for proteins?
•
• Codons
• Anticodon
• Exons
• Introns
• Splice site
• The glycosidic bond present at branching
points of glycogen molecule is:
•
• 1, 4 Glycosidic bond
• 1,6 Glycosidic Bond
• 2,4 Glycosidic Bond
• 2,6 Glycosidic bond:
• None of the above
• A substance that binds to a site other than the
active sites on an enzymes and decreases the
VMAX and has no effect on the KM is
•
• Product
• Competitive
• Non Competitive
• Substrate
• None of the above
• Which of the following binds to the A site of a
ribosome?
•
• T- Rna
• M-Rna
• SN- Rna
• R -Rna
• All of the above
•
• Which of the following metabolites is involved in
glycogenolysis, glycolysis, and gluconeogenesis?
•
• Galactose-1-phosphate
• Glucose-6-phosphate
• Uridine diphosphoglucose
• Fructose-6-phosphate
• Uridine diphosphogalactose
• All are intermediates of the Tricarboxylic Acid
cycle except:
•
• Acetyl CoA
• Fumarate
• Malate
• α Ketoglutarate
• Citrate
• Same amino acid is coded by multiple codons.
This property is known as:
•
• Degeneracy
• Frame-shift mutation
• Transcription
• Mutation
• Specificity
• The electron flow in Cytochrome C oxidase
can be blocked by:
•
• Rotenone
• Antimycin—A
• Cyanide
• Actinomycin
• Amytal