AAMC FL2

Question 1

energy equation, in terms of h / f / wavelength

Answer 1

E = hf = hc/λ, where h = 6.62 × 10 −34J ∙ s and c = 3 × 10 8 m/s

Question 2

calculating Kcat in terms of enzyme concentration and Vmax

Answer 2

kcat = Vmax/[E]

Question 3

chromatography using silica

Answer 3

silica gel is polar, thus will interact with polar solvents … non polar will travel farther / elute first

Question 4

what functional groups are polar? order them (7)

Answer 4

• COOH: 2 oxygens, can’t get any more than this
• CONH2: Same as above, but nitrogen is less electron withdrawing
• OH: O grabs all the electrons
• C=O: less polar than -OH because there is a bit of sharing by the carbonyl with its carbon
• CNH2: N doesn’t withdraw electrons very strongly from carbon; it also has a lone pair that it’s willing to pass around
• COOR: R group diminishes polarity
• COR: ethers aren’t really polar

Question 5

define half life

Answer 5

half-life of a radioactive material is defined as the time it takes for half of all the radioactive nuclei to decay into their daughter nuclei, which may or may not also be radioactive

Question 6

what do cooperativity graphs look like

Answer 6

the curves will have a sigmoidal shape

Question 7

venturi effect

Answer 7

Venturi effect depends on the conventions of Bournouille’s law. In the area of the mask openings, Pair = P + ρv2/2, thus Pair > P. The pressure of the oxygen inside of the mask is less than the atmospheric pressure outside of the mask. As a result of simple pressure differential, the air will come into the mask.

Question 8

triacylglcerols

Answer 8

+ structure

triacylglycerols are neutral storage lipids. They consist of three fatty acids ester-linked to a single glycerol.

Question 9

where does oxidation and reduction occur

Answer 9

RED CAT, AN OX

Reduction at cathode
oxidation at anode

Question 10

do catalysts increase or decrease the rate of a chemical reaction

Answer 10

catalysts INCREASE the rate of chemical reaction, which is the amount of product formed per unit time.

Question 11

define the following:

• coordinate covalent bonding
• covalent bonding
• ionic bonding

Answer 11

Coordinate covalent bond: unequal donation of electrons (ie one element is donating the electrons in the bond)

Covalent: equal donation of electrons

Ionic: unequal sharing of electron densities

Question 12

coordination number

2 examples

Answer 12

coordination number as the number of electron pairs the central atom is getting

Eg. If an atom is receiving two electron pairs from one ligand and has a total of 2 ligands, then its coordination number would be 4. Similarly, if a central atom is receiving one electron pair from a ligand and has four ligands, then it’s coordination number is 4.

Question 13

Henderson-Hasselbach equation

Answer 13

pH = pKa + log([base]/[acid])

Question 14

power

Answer 14

P=PE/time = mgh/t

measured in watts, or joules over seconds

Question 15

Which of the following energy conversions best describes what takes place in a battery-powered resistive circuit when the current is flowing?

Answer 15

Chemical to electric to thermal

the chemical energy of the battery elements is used as electrical energy to set the charge carriers in motion through the resistor, where they experience drag from the crystal lattice of the resistive conductor and dissipate their energy as heat from the resistor.

Question 16

secondary structure of proteins

Answer 16

repeated patterns of hydrogen bonds between the backbone amide protons and carbonyl oxygen atoms

Question 17

phosphodiester bonds

Answer 17

phosphodiester bonds link the 3ʹ carbon atom of one deoxyribose and the 5ʹ carbon atom of another deoxyribose within the DNA molecules

Question 18

etc reactions influence each other how?

Answer 18

ETC reactions are catalytically coupled to one another. Thus, inhibition of complexes I and II affects the activity of Complex III, which affects the activity of Complex IV.

Question 19

PFK-1 regulation

Answer 19

ATP, the end product of glycolysis, downregulates through feedback inhibition the activity of phosphofructokinase-1 by binding to a regulatory site other than the active site of the enzyme (allosteric regulation)

Question 20

what residues make up transmembrane proteins / domains

Answer 20

transmembrane domains are (by definition) able to cross the phospholipid bilayer

As a result, these domains are most likely to have a high proportion of hydrophobic residues because hydrophobic residues are nonpolar, thus allowing interaction with the lipid bilayer

Question 21

disulfide bonds

Answer 21

connect subunits in proteins via bonds btwn the thiol groups of cysteine residues

Question 22

vant hoff factor

Answer 22

(i) used to describe how many ions are present in a salt

Eg. NaCl → Na+ and Cl-, thus has a i = 2

Question 23

what promotes the production of estrogen

Answer 23

LH and FSH

Question 24

what happens when you add one nucleotide to an open reading frame

Answer 24

an open reading frame (ORF) is the part of a reading frame that has the ability to be translated; usually begins with a start codon (AUG) and ends w a stop codon (UAA, UAG, or UGA)

the addition of one nucleotide to the open reading frame of EGP results in a frameshift mutation and an aberrant carboxy-terminal domain, because translation is done in the 5’ to 3’ direction (thus N terminus to C terminus)

Question 25

the N terminus corresponds to the #’ end

vs the C terminus

Answer 25

N = 5
C = 3

Question 26

In humans, eggs and sperm are most similar with respect to ______

Answer 26

GENOME SIZE because both eggs and sperm contain a haploid number of chromosomes

Question 27

CTL

Answer 27

cytotoxic T lymphocytes target virus-infected cells by recognizing the viral antigen presented on the cell surface

Question 28

where does the sperm mature?

how does it get there before maturation?

Answer 28

sperm, produced in the seminiferous tubules of the testes, completes maturation and becomes motile in the epididymis

it is transported there from the testes via the cilia of the vas deferens

Question 29

what would adding a reducing agent do to a polymer in an SDS-page?

Answer 29

adding a reducing agent would eliminate any disulfide bridges (thus, breaking the peptide bonds) and allow the monomers to run separately