Random MCQs

Question 1

What is the major attractive force between
DNA & proteins in DNA-protein complexes in
cell cycle?

Answer 1

Hydrophobic interactions

Question 2

Most important AA needed for stability of

collagen triple helix?

Answer 2

Glycine.

Repeating motif in collagen: Gly-Pro-X

Question 3

AA that is is indispensable for normal collagen function

Answer 3

Glycine

Question 4

If α-helix is converted to β-sheets as in CJD
prion proteins, which bond is disrupted &
reformed?

Answer 4

Hydrogen bond

Question 5

unit of measure for sedimentation rate

Answer 5

Svedberg coefficient

Question 6

Shift to a more T state conformation

Answer 6

Increased Proton (H+) = acidic

Question 7

Most serious complication of blood transfusion therapy

Answer 7

Iron overload.

Question 8

Amount of iron in 1u pRBC (500mL)

Answer 8

250mg Fe (Iron).

Question 9

Hb & myoglobin are composed of which 20

structure?

Answer 9

α-helix

Question 10

How does mutation lead to aggregation of HbS?

Answer 10

hydrophobic area on surface of b-chains

missense mutation occurs: GAG -> GTG leading to Glu -> Val. Val is nonpolar

Question 11

Aquaporins belong to which transporter family?

Answer 11

alpha-channels

Question 12

Deficient transport protein in Leukocyte adhesion deficiency syndrome II (LAD II)

Answer 12

GDP-fucose transporter (FUCT1, SLC35C1).

Question 13

Pt w/ (+)neuropsychiatric symptoms, CLD,
parkinsonian tremors, ¯facial expression,
(+)choreoathetosis. What is deficient?

Answer 13

ATP7B.

He has Copper (Cu) transport defect: Wilson disease

Question 14

Menkes disease

Answer 14

Defective ATP7A

Question 15

Ouabain is poisonous since it is a potent

inhibitor of

Answer 15

Na+/K+ ATPases

Question 16

Main difference between GLUT2 & SGLT1

Answer 16

SGLT1 uses 20 active transport (active = up the concentration gradient).

GLUT2 uses facilitated transport (down the conc. Gradient)

Question 17

Which cell junction renders impermeability,

requiring transcellular movement of substances?

Answer 17

Tight junction (zona occludens)

Question 18

Which is associated w/ glucose uptake since it prevents phosphorylation of downstream effectors of insulin signaling cascade?

Answer 18

a-lipoic acid (LA).

Question 19

Which vitamin is water soluble, & can be synthesized in the
body but not sufficient to provide all coenzymes needed?

Answer 19

Niacin.

Question 20

Why will decreased Vit.B12 cause anemia?

Answer 20

B12 is involved in conversion of N5-methyl-THF to THF

Question 21

For rod cells to respond to light & transmit to optic nerve,
11-cis form of Vit. A should be attached to:____

Answer 21

Scotopsin.

Question 22

COBALAMIN is a coenzyme needed for

Answer 22

o Methionine synthase

o Methylmalonyl CoA mutase

Question 23

Which amino acid (AA) modifications need vit. K activity?

Answer 23

Glutamate (Glu) to γ-carboxyglutamate

Question 24

If decreased thiamin, which enzyme in RBC will have decreased activity?

Answer 24

Transketolase

Question 25

Pt w/ pernicious anemia will be unable to metabolize which compound?

Answer 25

Methylmalonyl-CoA

Question 26

ETOH alters activity of which

enzyme leading to lipid deposition in liver?

Answer 26

Glycerol-3-phosphate dehydrogenase (G3Pd).

Question 27

most common enzyme

deficiency causing inherited nonspherocytic hemolytic anemia

Answer 27

Pyruvate kinase