2013 biochem Flashcards
Which of the following has a role in mRNA splicing?
A. SnoRNA
B. SnRNA
C. Ribozymes
B. SnRNA
What is true about collagen protein?
A. Highly carboxylated
B. Highly glycosylated
C. Highly hydroxylated
C. Highly hydroxylated
Which of the following activates PPP? A. NAD B. AMP C. NADP D. NADPH
C. NADP
What’s the change that occurs in prion disease?
A. Increased Beta sheets
B. Increased alpha Helices
A. Increased Beta sheets
Protein kinases add phosphates on which of the following amino acid residues?
A. Serine
B. Lysine
A. Serine
A High-affinity competitive inhibitor has a resemblance to which of the following structures? A. Allosteric effector B. Substrate C. Product D. Cofactor E. Transition state
E. Transition state
What is the structural motif in the DNA binding domain of the intracellular glucocorticoid receptor?
A. Leucine zipper
B. Helix-turn-helix
C. Zinc finger
C. Zinc finger
What is the target sequence in lysosomal proteins?
A. Mannose 5-phosphate
B. Mannose 6-phosphate
B. Mannose 6-phosphate
A patient with hypertriglyceridemia has normal lipoprotein lipase. What should be checked next? A. ApoE B. ApoA-II C. ApoC-I D. ApoC-II
D. ApoC-II
A deficiency in which of the following causes hypocholesterolemia? A. ApoC-II B. ABC C. ApoE D. CETP E. LDL receptor
B. ABC
In order to measure free (unesterified) cholesterol in the plasma, what should be included?
A. Cholesterol oxidase
B. Cholesterol oxidase + cholesterol peroxidase
C. Cholesterol esterase + cholesterol oxidase
D. Cholesterol peroxidase
B. Cholesterol oxidase + cholesterol peroxidase
measure free cholesterol= cholesterol oxidase + cholesterol peroxidase
measure total cholesterol= cholesterol oxidase + cholesterol peroxidase + cholesterol esterase
What causes acidosis in prolonged starvation?
A. Ketone bodies
B. Fatty acid oxidation
C. Gluconeogenesis
A. Ketone bodies
Which lipid is abundant in skin?
A. Ceramide
B. Sphingolipid
A. Ceramide
Where are desaturases located inside the cell? A. Golgi apparatus B. nucleus C. Endoplasmic reticulum D. Mitochondria
C. Endoplasmic reticulum
Where are S-S disulfide bonds formed? A. Golgi apparatus B. Nucleus C. Mitochondria D. Endoplasmic reticulum
D. Endoplasmic reticulum
Where are ketone bodies synthesized?
A. Liver
B. Muscle
A. Liver
A person has hypoglycemia due to a defect in aldolase B. what should be cut from his diet?
A. Glucose
B. Galactose
C. Fructose
C. Fructose
What signals low energy level in the cell?
AMP
Which amino acid is involved in the urea cycle? A. Arginine B. Glutamate C. Methionine D. Proline
A. Arginine
Which process results in the formation of GTP in the TCA cycle?
A. Oxidative phosphorylation
B. Oxidative decarboxylation
C. Substrate level phosphorylation
C. Substrate level phosphorylation
What is the benefit of glucose phosphorylation in the preparatory phase of glycolysis?
A. To decrease its energy
B. Trapping glucose inside the cell
B. Trapping glucose inside the cell
Starting the synthesis of a new glycogen molecule requires a central molecule, which molecule is at the center of every glycogen?
Glycogenin
Initiation of translation in eukaryotes is different from that of prokaryotes in which of the following?
A. Lower energy required
B. Lower number of factors
C. Scanning for the initiation code
C. Scanning for the initiation code
How can nucleotide analogs slow down cancer growth rate? A. Inhibit helicase B. Inhibit DNA replication C. Inhibit telomerase D. DNA proof reading
B. Inhibit DNA replication
Which enzyme catalyzes the rate limiting step of fatty aid synthesis? A. Fatty acid synthase B. Acyl CoA synthase C. HMG-CoA reductase D. Acetyl CoA carboxylase
D. Acetyl CoA carboxylase
Which substrate activates acetyl CoA carboxylase when glucagon level is low?
A. Citrate
B. Fumerate
A. Citrate
A figure shows Complex V of the electron transport chain. What part of Complex V binds the ATP? and what triggers it’s phase changes?
A. F0, Flow of H+
B. F0, ATP hydrolysis
C. F1, Flow of H+
C. F1, Flow of H+
A patient suffers from glycogen storage disease I (Von Gierke’s) due to a deficiency in glucose phosphatase in the liver. Which of the following is a symptom of this condition?
A. low blood glucose
B. Intolerance to exercise
A. low blood glucose
Which of the following has been used in DNA finger printing? A. Alu family B. Telomeres C. Centromeres D. Hypervariable minisatellite DNA
D. Hypervariable minisatellite DNA
What is inhibited by malonyl CoA to inhibit Beta-oxidation of fatty acids?
Carnitine Acetyltransferase (rate-limiting transport of fatty acyl CoA into mitochondrial matrix is called as “carnitine shuttle”, stopping the enzyme stops it)
Which of the following is the main method to study lipidomics?
Mass spectrometry
The genetic mutation in chloride channels that causes cystic fibrosis affects which of the following?
ATP binding domain
What is the function of the BCR-ABL-encoded fusion protein?
Tyrosine kinase activity
Which of the following is a mechanism of epigenetic inhibition?
A. Acetylation
B. Methylation
B. Methylation
What is a characteristic of membrane rafts?
A. No cholesterol
B. Sphingolipid and protein
B. Sphingolipid and protein
Palmitic acid has 16 carbons although its precursors give a total of 23 carbons. Where do the extra 7 carbons go?
Decarboxylated giving 7 CO2
Boiling eggs result in solidification due to disruption of which bonds?
A. S-S disulfide bonds
B. Covalent bonds
C. H-bonds
C. H-bonds
