AAMC 1 Chem/Phys

Question 1

In chromatography, what would determine the relative rate of migration of the various components?

Answer 1

The relative rate of migration of the various components will depend on the amount of hydrogen bonding to the stationary phase.

Question 2

If both fumaric and maleic is acid are produced from the dehydration of malic acid it tells you that?

Answer 2

It tells me that the dehydration of malic acid is NOT stereospecific.

Question 3

What functional group is formed during the formation of a peptide bond?

Answer 3

The group that forms during a peptide bond formation is a an Amide group.

Question 4

If 1-pentanol is replaced by 2-pentanol the rate of a substitution reaction changes in what way and why?

Answer 4

The rate of substitution in protonated alcohols is subject to steric hindrance changing a primary OH to a secondary one will decrease the rate of the reaction (substitution)

Question 5

If a solution containing a variety of compounds, the first peak observed is the go trace will be attributable to?

Answer 5

In gas chromatography compounds with lower boiling point, smaller/lighter in molecular weight, will show first in the chromatogram.

The very first peaks are often the solvent, however

The compound with the lowest molecular weight and the weakest intermolecular forces of attraction. This will make the migration faster and make it the first peak in the gas chromatography.

2-methyl-2-butene will show first than 2-bromo-2-methylbutane

Gas chromatography compounds are often run with a reference that allows ball park estimation of the compound and it is coupled with other analytical tools such as mass spectrometry

Question 6

In gas chromatography the area underneath the peak is directly related to?

Answer 6

In gas chromatography the area underneath each peak is directly proportional to the amount of compound in the mixture.

Question 7

What formula do you use to calculate the strength of a persons eye’s lens?

Calculate it for a person with lens to retina distance of 2cm that can only see objects that are 1m away.

Answer 7

The thin lens formula is S= 1/O+1/I

The formula is the inverse of the foal length of the eye lens.

1D+50D= 51D

Question 8

In enzyme kinetics the stabilization of?

Answer 8

The transition state provides binding energy that is used to change (lower) the activation energy of a reaction.

Question 9

Adding what to an acid will decrease the percentage of ionization of a weak acid?

Answer 9

Adding a strong acid like HCl will decrease the percentage that ionizes from the other acid by increasing the amount of H+ in solution.

Question 10

If current in a circuit increases and the resistance of the circuit remains the same, the voltage of the circuit?

Answer 10

INCREASES.

According to Ohm’s law, current is equal to voltage divided by resistance, so (I= V\R) if the current increases and the resistance is constant then voltage increases as well.

Question 11

How do yo calculate the index of refraction of a medium?

If the speed of light in the medium is 2.1•10^8 m/s

Answer 11

The index of refraction of a medium is equal to the ration of the speed of light in a vacuum tot he speed of the light in the medium.

So 3•10^8/2.1•10^8= 1.4 no units

Question 12

How is the energy of electromagnetic radiation measured?

Answer 12

The energy of electromagnetic radiation is directly proportional to the number of photons, and the INTENSITY of electromagnetic radiation is defined as the energy emites per unit time. The intensity is directly proportional to the number of photons emitted.

Question 13

What fraction of compound X will decay in 12 minutes if it has a half life of 3 minutes?

Answer 13

The fraction that will decay in 12 minutes if the half life is 3 minutes is 12/3= 4 1/2^4 = 16\16-1/16 is equal to 15/16

Question 14

What are the units for Watts?

Answer 14

The units for Watts are joules/seconds

Question 15

Disulfide bond formation is made by the formation of what kind of bond?

Answer 15

It is made by covalent bond formation.

Question 16

What feature of a molecule is or are responsible for the pH dependence of aggregation?

Answer 16

Side chains whose net charge respond to pH such as acidic side chains that are neutral at low pH. This inhibit aggregation due to electrostatic principles.

Question 17

Why is the velocity of blood flow slower in capillaries than in arteries?

Answer 17

Because the total (net) cross-sectional area of capillaries exceeds that of arteries.

Question 18

In a graph showing the relationship between solution pH and applied potential. Lines that are horizontal or perpendicular means?

Answer 18

That the compound is at equilibrium at either pH (horizontal) or Voltage (perpendicular), for both (diagonal)

Question 19

Hybridization of 5 bonds? 6?

Answer 19

d^2sp^3 for six alpha bonds and dsp^3 for 5 bonds

Question 20

What are the assumptions made when referring to a gas as, “ideal gas”?

Answer 20

The properties of an “ideal” gas is that it is composed of particles that have negligible volume and do not exert intermolecular forces.

Question 21

The production of variety of opsins functions to?

Answer 21

The wavelength of light absorbed by a molecule depends on its structure, and so the production of a variety of structurally related opsins functions to enable the detection of different colors.

Question 22

A compound made of Carbon and hydrogen will make it largely?

Answer 22

Hydrophobic

Question 23

When thinking of kinases think of ?

When thinking of co-factors think of?

Answer 23

Kinases should bring phosphate to mind is the source of phosphates inorganic or from ATP?

Cofactors are enzyme helpers that contain a METAL.

Question 24

What reaction is catalizador by an enzyme like LipA?

Answer 24

LipA is a lipase, which means it hydrolyze fatty acids.

Question 25

The following mutations occurred R33G, K112D, M134D, Y139C, I157M what is the change in NET charge?

Answer 25

1-0, 1-(-1), 0-(-1), 0-0, 0-0

Initially 2 at the end -2 NET difference-4

Question 26

What kind of sugar is present in UDP?

Answer 26

Ribose. UDP contains Uridine which is a nucleic acid used in RNA, and RNA contains ribose.

Question 27

What is the action of the laforin?

Answer 27

Laforin is an enzyme that removes phosphate from glycogen.

Question 28

What happens during the radioactive decay known as b-1?

Carbon is converted into what? For example

Answer 28

During b-1 radioactive decay a neutron is converted into a proton.

A carbon would be converted into a nitrogen.

Question 29

The amount of what type of bond is decreased in Lafora bodies?

Answer 29

The lack of branching is a characteristic of Lafora bodies. Branching occurs through an alpha-1,6-glycosidic bond in glycogen

Question 30

A convex (converging) lens will give you what sign in your answer? What about a concave (diverging)?

Answer 30

A concave will give you a psotive sign and a diverging concave will give you a negative sign.

Question 31

Magnification formula is equal to?

Answer 31

Magnification formula is M= -distance of image/ distance of object or -height of image/ height of object

Question 32

See picture, and Object is at a distance of three focal lengths from the center of a convex lens. What is the ratio of the height of the image to the height of the object?

Write it on a piece of paper.

Answer 32

You will need the thin lens equation and the magnification equation

Thin lens equation: 1/O+1/i= 1\f

Magnification equation: -or +i/O

Object distance: 3f, focal length:f image distance: i

Answer should be 1/2

Question 33

Gamma decay occurs when a nucleous emits?

Answer 33

By definition gamma decay means the emission of photons by the nucleus, known as gamma rays

Question 34

Spontaneous reaction should have?

Answer 34

A negative change in G and a positive S for entropy, as the compound goes from liquid to gas.

Question 35

If a homogenous catalyst cannot be removed from the products then?

Answer 35

If a homogenous catalyst cannot be removed from the products at the end of a reaction then the products will be contaminated with the catalyst.

Question 36

How will the rate of a catalyze reaction be affected if the solid catalyst is finely ground before it is added to the reaction?

Answer 36

The rate will be faster because there will be an increase in the amount of catalyst by the increased surface area the catalyst will be exposed to, increasing the rate.

Question 37

What is an effective way of increasing a current by two?

Answer 37

According to ohms law the current is equal to the voltage divided by the resistance. I=V/R So if the resistance is halved the current should increase by two. The voltage could also be multiplied by two.

Question 38

If a compound that is a solid and a compound that is a liquid (cation) are mixed and a new compound is formed it is reasonable to say that?

If the liquid (when solid) evolves when placed in an acid, what is reasonable to say about the original solid compound when added to the acid.

Answer 38

That the solid is more susceptible to oxidation that the liquid. Since the liquid was reduced into a solid that cannot be ionized.

It is reasonable to say that it will evolve as well

Question 39

What volume of .120Moles solution would contain .078 moles of solute?

Do it in a piece of paper

Answer 39

Answer should be 650mL

Question 40

If deletions in a microsatellite on an intron cause an Exon to be omitted from the final mRNA what does it suggest about the microsatellite?

Answer 40

It would suggest that the microsatellite contains sequences that influence splicing such as an splice acceptor site.

Question 41

What is the function of a chaperone protein?

Answer 41

What is the function of a chaperone protein?

A protein that facilitates proper folding and inhibits the formation of nonfictional protein aggregates such as heat shocked proteins are an example of chaperone proteins.