AAMC FL 2

Question 1

Which amino acid’s side chain is frequently encountered at the active site of metalloenzymes?

Answer 1

Histidine. Active sites of metalloenzymes resemble the five-membered imidazole rings associated with histidine.

Question 2

Absorption of ultraviolet light by organic molecules always results in what process?

Answer 2

Excitation of bound electrons

Question 3

Increasing the polarity of the eluting molecule will increase its affinity for the stationary phase and (increase or decrease) the elution time?

Answer 3

Increase the elution time. Decreased retention factor.

Question 4

The half-life of a radioactive material is the time it takes for half of all the radioactive nuclei to decay into (daughter or radioactive) nuclei?

Answer 4

Daughter nuclei which may or not also be radioactive.

Question 5

Why must the person either lean forward or slide their feet under the chair in order to stand up?

Answer 5

To keep the body in equilibrium while rising

Question 6

Aromatic side chains absorb in the near UV region of the electromagnetic spectrum, which has longer wavelengths, and hence lower energy, than peptide bonds.

Answer 6

Aromatic side chain has more closely spaced energy levels.

Question 7

What type of curves indicate cooperative processes?

Answer 7

Sigmoidal curves (S-shaped)

Question 8

A decrease in oxidation number is a reduction or an oxidation?

Answer 8

Reduction

Question 9

G-C base pairs form (stronger or weaker) pi-stacking interactions than A-T base pairs.

Answer 9

Stronger. Most thermal stability. Increase in melting temperature in GC-rich DNA

Question 10

The lone pair of electrons in ammonia allows the molecule to act as a Lewis (acid or base) in water.

Answer 10

Lewis base that donates the electron pair in forming a covalent interaction.

Question 11

When K is greater than 1,

Answer 11

the reaction’s deltaG is negative and the reaction is spontaneous.

Question 12

The Lewis acid-base interaction between a metal cation and an electron pair done is known as a ___ bond?

Answer 12

Coordinate covalent bond

Question 13

In DNA, sugar-phosphate backbones form the (interior or exterior) of the double helix.

Answer 13

Exterior

Question 14

Bonds between identical atoms are likely to be the (least or most) polar ?

Answer 14

Least polar

Question 15

Negative focal length = diverging lens. What type of image do it form?

Answer 15

Virtual and reduced images of objects situated at distances larger than the focal length.

Question 16

Protein secondary structure is represented by repeated patterns of hydrogen bond between

Answer 16

the backbone amide protons and carbonyl oxygen atoms.

Question 17

Ubiquitination targets a protein for ____ by a proteasome.

Answer 17

Degradation

Question 18

Posttranslational modification of proteins such as histone acetylation is analyzed by what type of blotting?

Answer 18

Western blotting (SNOW DROP)

Question 19

The brain is derived from what germ layer?

Answer 19

Ectoderm (central nervous system)

Question 20

The tips of an antibody are the what type of regions?

Answer 20

The variable regions (specific for a particular antigen)

Question 21

Dependency ratio

Answer 21

The number of economically dependent members of the population (too young or too old) to the number of economically productive members (working-age 16-85)