Biochemistry Flashcards
What is the reverse of glycolysis?
A. Gluconeogenesis
B. Glycogenesis
C.Glycogenolysis
D. HMP shunt
E. Ketogenesis
A. Gluconeogenesis
What is the rate-limiting enzyme of glycolysis?
A. Fructose-1,6-bisphosphatase
B. Phosphofructokinase-1
C. Glucose-6-phosphate dehydrogenase
D. Pyruvate kinase
E. Enolase
B. Phosphofructokinase-1
What is the enzyme deficiency in Tay-Sachs disease?
A. Sphingomyelinase
B. B-galactosidase
C. Ceramidase
D. B-glucosidase
E. Hexosaminidase A
E. Hexosaminidase A
True about proteins:
A.Denaturation does not affect a protein’s secondary structure
B.Proline and glutamine can disrupt the alpha helix structure
C. Primary structure is determined by the amino acid sequence of a protein
D.Hemoglobin and myoglobin can form quaternary structures
E. All of the above
C. Primary structure is determined by the amino acid sequence of a protein
Ratio:
A.Denaturation does not affect a protein’s secondary structure - it should be primary
B.Proline and glutamine can disrupt the alpha helix structure - it should be glycine
D.Hemoglobin and myoglobin can form quaternary structures - hemoglobin only
This amino acid terminus contains retention signals for protein sorting
A. N-terminal
B. C-terminal
C. Both A and B
D. Neither A nor B
B. C-terminal
Zeroth law of thermodynamics states that…
A.If two systems are each in thermal equilibrium with a third system, then, they are in thermal equilibrium with each other
B.When energy passes into or out of a system, the system’s internal energy changes in accord with the law of conservation of energy
C.In a natural thermodynamic process, the sum of the entropies of the interacting thermodynamic systems never decreases
D. A system’s entropy approaches a constant value as the temperature approaches absolute zero
E.Energy can neither be created nor destroyed, but can only change in form
A.If two systems are each in thermal equilibrium with a third system, then, they are in thermal equilibrium with each other
Ratio:
FIRST LAW - When energy passes into or out of a system, the system’s internal energy changes in accord with the law of conservation of energy
SECOND LAW - In a natural thermodynamic process, the sum of the entropies of the interacting thermodynamic systems never decreases
THIRD LAW - A system’s entropy approaches a constant value as the temperature approaches absolute zero
LAW OF CONSERVATION OF ENERGY - Energy can neither be created nor destroyed, but can only change in form
Basis for current pharmacotherapy for
Alzheimer’s disease
A. Cholinergic theory
B. Amyloid theory
C. Tau hypothesis
D. Apolipoprotein E hypothesis
E. NMDA theory
A. Cholinergic theory
Menkes disease is a problem in what step of collagen sythesis?
A. Hydroxylation of proline and lysine
B. Glycosylation
C. Exocytosis of procollagen
D. Proteolytic processing
E.Cross-linking of tropocollagen fibers
E.Cross-linking of tropocollagen fibers
Ratio:
SCURVY - Hydroxylation of proline and lysine
Found in DNA except
A. Adenine
B.Guanine
C. Thymine
D. Uracil
E.Cytosine
D. Uracil
It is replaced by Thymine
Part of a vitamin deficiency except
A.Hallucinations
B. Peripheral neuropathy
C. Diarrhea
D. Hyperpigmentation of sun-exposed limbs
E.Dementia
B. Peripheral neuropathy
Pellagra
- neurological impairments (delusions or hallucinations)
- skin inflammation (dermatitis)
- naused
- decreased appetite
- watery diarrhea
Manganese serves as a cofactor in the following enzymes except
A. Arginase-1
B. Glycosyltransferases
C. Xanthine oxidase
D. Pyruvate carboxylase
E. Mitochondrial SOD
C. Xanthine oxidase
Which statement is true?
A.Noncompetitive inhibitors bind to the active site of the enzyme
B.Noncompetitive inhibitors can be reversed by increasing the substrate
c. There is an increase in Km but no change in max in noncompetitive inhibition
D.Malathion is a noncompetitive inhibitor of atetylcholinesterase.
E.Statin is a noncompetitive inhibitor of
HMG CoA reductase.
D.Malathion is a noncompetitive inhibitor of atetylcholinesterase.
True about organization of DNA:
A. H1 is seen in linker region
B. H2A and H2B are rich in lysine
C. H3 and H4 are rich in arginine
D. Phosphate groups give DNA a positive charge
E.Lysine and arginine give histones a negative charge
A. H1 is seen in linker region
Ratio:
A. H1 is seen in linker region l1nker
B. H2A and H2B are rich in argInIne
C. H3 and H4 are rich in lysine
D. Phosphate groups give DNA a negative charge PO,-3
E. Lysine and arginine give histones a positive charge
Amino acid that accumulates in phenylketonuria
A. Phenylalanine
B. Tyrosine
C. Valine
D. Leucine
E. Isoleucine
A. Phenylalanine
Ratio:
A. Phenylalanine - accumulation
B. Tyrosine - deficiency
True about uncouplers except
A.Uncoupling agents increase the permeability of membrane causing a decrease in proton gradient and increase oxygen consumption
B. ATP synthesis stops but electron transport continues
C.Produces heat
D. 2,4-Dinitrophenol and oligomycin are examples
E.None of the above
D. 2,4-Dinitrophenol and oligomycin are examples
