Random MCQs Flashcards
What is the major attractive force between
DNA & proteins in DNA-protein complexes in
cell cycle?
Hydrophobic interactions
Most important AA needed for stability of
collagen triple helix?
Glycine.
Repeating motif in collagen: Gly-Pro-X
AA that is is indispensable for normal collagen function
Glycine
If α-helix is converted to β-sheets as in CJD
prion proteins, which bond is disrupted &
reformed?
Hydrogen bond
unit of measure for sedimentation rate
Svedberg coefficient
Shift to a more T state conformation
Increased Proton (H+) = acidic
Most serious complication of blood transfusion therapy
Iron overload.
Amount of iron in 1u pRBC (500mL)
250mg Fe (Iron).
Hb & myoglobin are composed of which 20
structure?
α-helix
How does mutation lead to aggregation of HbS?
hydrophobic area on surface of b-chains
missense mutation occurs: GAG -> GTG leading to Glu -> Val. Val is nonpolar
Aquaporins belong to which transporter family?
alpha-channels
Deficient transport protein in Leukocyte adhesion deficiency syndrome II (LAD II)
GDP-fucose transporter (FUCT1, SLC35C1).
Pt w/ (+)neuropsychiatric symptoms, CLD,
parkinsonian tremors, ¯facial expression,
(+)choreoathetosis. What is deficient?
ATP7B.
He has Copper (Cu) transport defect: Wilson disease
Menkes disease
Defective ATP7A
Ouabain is poisonous since it is a potent
inhibitor of
Na+/K+ ATPases
Main difference between GLUT2 & SGLT1
SGLT1 uses 20 active transport (active = up the concentration gradient).
GLUT2 uses facilitated transport (down the conc. Gradient)
Which cell junction renders impermeability,
requiring transcellular movement of substances?
Tight junction (zona occludens)
Which is associated w/ glucose uptake since it prevents phosphorylation of downstream effectors of insulin signaling cascade?
a-lipoic acid (LA).
Which vitamin is water soluble, & can be synthesized in the
body but not sufficient to provide all coenzymes needed?
Niacin.
Why will decreased Vit.B12 cause anemia?
B12 is involved in conversion of N5-methyl-THF to THF
For rod cells to respond to light & transmit to optic nerve,
11-cis form of Vit. A should be attached to:____
Scotopsin.
COBALAMIN is a coenzyme needed for
o Methionine synthase
o Methylmalonyl CoA mutase
Which amino acid (AA) modifications need vit. K activity?
Glutamate (Glu) to γ-carboxyglutamate
If decreased thiamin, which enzyme in RBC will have decreased activity?
Transketolase
Pt w/ pernicious anemia will be unable to metabolize which compound?
Methylmalonyl-CoA
ETOH alters activity of which
enzyme leading to lipid deposition in liver?
Glycerol-3-phosphate dehydrogenase (G3Pd).
most common enzyme
deficiency causing inherited nonspherocytic hemolytic anemia
Pyruvate kinase
