AAMC 1

Question 1

what is the formula for the index of refraction?

Answer 1

Index refract= speed of light (3.0*10^ m/s) / speed of travel in the new medium (x m/s)

I= c/v

Question 2

the intensity of radiation depends on… frequency or number of photons?

Answer 2

photons. frequency gives you the energy for a single photon but radiation is many photons

Question 3

the prefix tera means what order of magnitude?

Answer 3

10^12

Question 4

1 atm =… torr… Pa

Answer 4

760 torr/mmHg … 101325 Pa

Question 5

what are some characteristics of ideal gases?

Answer 5

ideal gas particles do not have a mass and have negligible IMF. they take up 22.4 L at STP 0 celsius

Question 6

what type of bond is between the glucose in glycogen? branched?

Answer 6

alpha 1-4 glycosidic bonds in regular linear. alpha 1-6 links in branching (think of the spacial requirements of that. makes sense right?)

Question 7

what do phosphatases do? what would this do to the intensity of an SDS-PAGE band that looks for flagged phosphorus?

Answer 7

phosphatases cleave off phosphorus groups. if the SDS page were looking for proteins with phosphorus attached, then there would be fewer to see, so less intensity

Question 8

How do you find Ecell? how do you know the reaction will be spontaneous?

Answer 8

Ecell= E (red) - E (ox)

the E cell must be positive for the reaction to proceed (think “redox”)

Question 9

If a mutation is only fond in certain cells, will it be inherited?

Answer 9

No! bc it is not genetic in that case! if a mutation is inherited, it will be that way in every single cell

Question 10

How can a single gene code for multiple proteins?

Answer 10

this is due to alternative splicing of the mRNA

Question 11

what does NADH stand for?

Answer 11

Nicotinamide Adenine Dinucleotide +H (on the nicotinamide)

Question 12

please explain the four stages of the actin myosin cross bridge with relation to ATP

Answer 12

1. HIGH energy = starting with the attached myosin to the actin binding site (exposed by Ca2+ lift troponin from tropomysin)
   [ADP and Pi attached]
2. the power stroke is when the third phosphate detaches and myosin uses this this energy to move even further from cocked, BENT myosin
   [ADP attached, Pi released]
3. the detachment phase is when myosin lets go of actin
   [new ATP attaches here]
4. LOW energy = COCKED myosin loaded position all the way down far from actin

Question 13

which is the most concentrated part of the kidney nephron? which part of the collecting duct comes first? cortical or medullary?

Answer 13

The urine is most concentrated in the medullary collecting duct

the cortical (“core”) collecting duct flows into the medullary duct

Question 14

do action potentials change in their intensity?

Answer 14

NOPE its an all or nothing thing of whether or not the stimulus provides enough to trigger it. then its just the same after

Question 15

what is the difference between adherens junctions and desmosomes? which is stronger?

Answer 15

adherens junctions bind neighboring cells by their actin microfilaments, desmosomes bind neighboring cells with intermediate filaments instead. Therefore, desmosomes are much stronger.

“stronger bear desi”

Question 16

what on earth does a transcription factor do?

Answer 16

TF’s bind DNA and recruit RNA polymerase

Question 17

what 2 things specifically am i thinking of that help a larger molecule diffuse directly through a cell membrane?

Answer 17

if it is nonpolar (lots of benzenes) and planar (slicing through?)

Question 18

what is the function of cholesterol in the cellular membrane?

Answer 18

cholesterol helps with fluidity/strength and most importantly decrease permeability

Question 19

complete the sentence: enzymes are biological…

Answer 19

…catalysts. hudurrrr

Question 20

in the citric acid cycle, where do the two C’s from acetyl coA end up? what all is produced from this cycle?

Answer 20

the two C’s from acetyl coA end up as CO2. other things that are produced here are GTP, FADH2, and 3 NADH

“CO2? Girl Friend, No!!!”

Question 21

do red blood cells have DNA?

Answer 21

nope. they don’t even have a nucleus so that they can have that concave shape. they are sacks of hemoglobin

Question 22

can viruses reproduce on their own?

Answer 22

No! they need a host bro, viruses can have either DNA or RNA (not always just RNA)

Question 23

what do bacterial DNA strands look like?

Answer 23

all bacteria are eukaryotes and as such have DNA, but their DNA is circular. some are even smaller circles called plasmids

Question 24

give me the two formulas for thin lenses

Answer 24

(1/f) = (1/di) +(1/do)  where a negative di means same side
M= -(di/do)             where negative means upside down

Question 25

please explain what happens at a neuromuscular junction. what type of channels are opened?

Answer 25

the neuron (at synapse) to a muscle cell (at endplate)

1. the action potential at the axon terminal releases acetylcholine neurotransmitter
2. the acetylcholine then opens ligand-gated Na+ channels in the muscle endplate
3. the Na+ then triggers voltage gated and action potential occurs with the muscle!