AAMC FL #1

Question 1

Retardation factor

Answer 1

Rf

Rf = distance spot moved/ distance solvent front moved

Question 2

If a reaction yields 2 different products -the cis and trans isomers, then…

Answer 2

then this means the reaction is NOT stereospecific to a certain isomer

Question 3

On small scale, TLC used to __________

On large scale, TLC used to __________

Answer 3

On small scale, TLC used to identify unknown compounds.
On large scale, TLC used to purify sample into their individual compounds, which is then separated to yild pure compounds - called preparative TLC

Question 4

Gas chromatography/ vapor-phase chromatography separates ____.
Also mobile phase is _____ and stationary phase is _______

Answer 4

by boiling points (intermolecular forces) and molecular weights. So lower boiling points and lowest molecular weights and compounds with less intermolecular forces will elute first.
Mobile phase is INERT gas and stationary phase is some metal in the coiled column that is HEATED

Question 5

Sn2 stereospecificity

Answer 5

SN2 has stereospecificity - means the incoming nucleophile attacks only on the side that is opposite to the leaving group
So you observe inversion of configuration

Question 6

What is the mechanism behind Acetic acid + alcohol ==> ester

Answer 6

Reaction occurs under acidic conditions which protonates the carbonyl oxygen. Alcohol(nucleophile) then attacks electrophilic carbonyl carbon, electrons kick up– OH from carboxylic acid gains proton from newly attached ROH group — electrons then go down, to kick off newly formed water

Question 7

If you have a weak acid like CH3CO2OH, what will happen if you add HNO3

Answer 7

HNO3 or nitric acid is a strong acid similar to HCl so it will ionize well in the solution; And this will prevent a weak acid like CH3CO2OH from ionizing as much in the solution.
Adding a strong acid to a solution of weak acid will decrease the amount of ionization of the weak acid.

Question 8

How do you find index of refraction in a medium if given speed of light within the medium?

Answer 8

Index of refraction in medium = n
speed of light within medium = v
Speed of light in vacuum = c = 3 *10^8 m/s
Speed of light with medium is always lower than c (in vacuum) and index of refraction in vacuum is 1 so everything else has n> 1
n = c/v is the formula

Question 9

Intensity of the radiation emitted by the oxygen sensor (which absorbs photons from light and emits photons) is directly proportional to the_________

Answer 9

….the number of photons emitted
E = hf
Energy of electromagnetic radiation is directly proportional to the number of photons, and the intensity of electromagnetic radiation is defined as energy emitted per unit time. Thus, intensity is directly proportional to the number of photons emitted.

Question 10

1 THz = ? Hz

Answer 10

1 THz = 10^12 Hz

Question 11

1 Watt = ? what times what?

Answer 11

1 Watt = Joule * SECOND!!!

Question 12

Octahedral Compounds have how many bonds?

Answer 12

Octahedral compounds have 6 sigma bonds and no lone pairs; so need to hybridize 6 atomic orbitals - and you get d2sp3

Question 13

Assumptions of ideal gas

Answer 13

It is composed of particles that have negligible volume and do not exert intermolecular forces; add others***

Question 14

What should you remember when asked for hybridization state for a carbon atom in a particular compound?

Answer 14

remember to look and account for any lone pairs of electrons towards the hybridization state

Question 15

function of lipases

Answer 15

lipases hydrolyze fatty acids — or triacylglycerides

Question 16

At a pH of 7, R has a charge of?

Answer 16

R = arginine. -1 charge at pH 7

Question 17

K87Y Amino acid substitution

Answer 17

Lysine is substituted with TYrosine

K is substituted with Y

Question 18

What is the main linkage of glycogen? And what is released when this bond is formed? And what enzyme helps form this bond?

Answer 18

α-1,4-glycosidic bond
UDP is released
Glycogen Synthase

Question 19

Carbohydrate branching occurs with what bonds?

Answer 19

Branching occurs through an α-1,6-glycosidic bond in glycogen

Question 20

Why will HPO4 2- dissociate to the least extent??

Answer 20

HPO42− has a high negative charge and so dissociation of it will occur to the least extent

Question 21

What is the thin lens equation and how does it relate distances between real and object, and image vs. object height

Answer 21

the ratio of the image height to the object height is equal to the ratio of the lens-image distance to the object-lens distance
hi/ho = -di/do
this is actually equal to magnification m

Question 22

A reaction that creates gas products from solids and liquids must have a + or - ΔS°

Answer 22

A positive ΔS°

Question 23

A new solid forms when Al(s) is mixed with Zn2+ (aq), so it is reasonable to assume what?

Answer 23

Assume that Al(s) is more susceptible to oxidation than Zn(s)

Question 24

In electrochemistry, a spontaneous reaction occurs when E° is…

Answer 24

When E° is greater than 0 then a spontaneous reaction occurs

Question 25

A mutation can only be passed on to children if it is in…

Answer 25

the germ line; if mutation is in germ line it is passed on; if it is in a somatic cell, mutation will not be inherited

Question 26

Chaperone

Answer 26

facilitate proper protein folding and inhibit formation of nonfunctional protein aggregates

Question 27

Clathrin

Answer 27

plays a major role in the formation of coated vesicles

Question 28

chemiosmosis

Answer 28

movement of ions across a semipermeable membrane, down their electrochemical gradient. An example of this would be the generation of adenosine triphosphate (ATP) by the movement of hydrogen ions (H+) across a membrane during cellular respiration or photosynthesis.

Question 29

medullary portion of collecting duct is _____ concentrated than cortical portion of the collecting duct

Answer 29

more concentrated

Question 30

activity (especially for enzymes) is a _______ property

Answer 30

activity is a kinetic property while free energy is a thermodynamic quantity

Question 31

Transcription factors bind to…?

Answer 31

DNA!!!

Question 32

Kinase

Answer 32

An enzyme that catalyzes the transfer of a phosphate group from ATP to a specified molecule

Question 33

(ABC transporters)

Answer 33

ATP-binding cassette transporters

Question 34

enzymes can..

Answer 34

colocalize substrates, alter local pH, and alter substrate shape

Question 35

What is true about erythrocytes after they mature?

Answer 35

Mammalian erythrocytes lose their nuclei (and thus DNA) during maturation; so RBCs don’t contain DNA!!