MCAT error review Qs

What happens to AA charge upon pH drop?

its charge becomes more positive

do breaking bonds release or absorb energy?

absorb

ideal gas law and variable meanings

PV=nRT

P= pressure

V= volume

n=moles

R=gas constant

T=temp

how to solve for partial pressure?

partial pressure of A = total pressure x mole fraction of gas A

what causes deviations from ideal gas behaviors?

large volumes & more significant IMFs

is enthalpy a state or path function?

state

does an exothermic reaction require more or less energy to break bonds of reactants than to form them as products?

less

equivalencies from kPa to torr to mmHg to atm

1 atm = 760 mmHg

1 atm = 101 kPa

1 mmHg = 1 torr

what do all the T lymphocytes do?

Helper T : release cytokines to activate other immune cells

Cytotoxic T: destroy infected cells

Regulatory T: suppress immune activity after infection to prevent healthy tissue from being attacked

Memory T: remember past infections

explain clonal selection

B or T cell clones responsive to an antigen are stimulated to replicate

MCH binding

holds antigens in place to let T cells inspect them

what do B lymphocytes do?

produce antibodies

what difference exists between innate and adaptive immune responses?

adaptive immune system only binds one type of antigen

Does a positive or negative peptide elute faster?

negative

what type of AA do proteases act on and why?

L-AA, not D, because L-AA are more commonly found in nature

What happens to binding affinity as Kd increases?

it decreases

accuracy vs precision

accuracy is closeness to target & precision is replicability

how to calculate kDa from AA number?

AA#/10=kDa

what is removed in a peptide bond?

OH from COOH end and H from NH3+ end

list the traits of 1-4 protein structure:

1: linear

2: folding of backbone; H bond interactions

3: H bonding, LDFs, disulfide bridges

4: subunit formation

what happens to Km and Max in competitive inhibition?

Km increases and Vmax remains constant

what happens to Km and Vmax in non-competitive inhibition?

Km remains constant and Vmax decreases

How does Ks relate to binding affinity?

increased Ks decreases binding affinity

what happens to disulfide bonds in reducing gels?

they are broken

where do histones bind to?

DNA backbones

what is another word for luminous?

aqueous

when is ionization energy highest?

when removing an electron from the first valence shell

are molecules with low ionization energy reactive or unreactive and why?

reactive because if the electron requires little energy to remove, it must be loosely held. if the e- are loosely held they, they can interact more with other molecules.

do smaller atoms have stronger or weaker bonds and why?

stronger, because their nuclei are closer together

do strong acids bind weakly or strongly?

weakly

do metals get more or less reactive as their size increases?

more reactive

do non-metals get more or less reactive as their size increases?

less reactive

in what direction of the periodic table does EN and EA increase?

EA & EN : increase across a period & decrease down a group

what phenotype does X silencing lead to?

mosaic

describe X silencing?

only 1 chromosome is active, the other is turned off, and the active one differs from cell to cell

formula for allele frequency

p+q=1

formula for genotype frequency

p²+2pq+q²=1

is inbreeding random or non random mating?

non-random

what does calcitonin regulate?

calcium

where is calcitonin produced and what does it do?

produced in thyroid gland; brings Ca into bone from blood (ossification)

what does PTH do?

bring Ca into blood from bone (reabsorption) & stimulates vitamin D production in kidney

what enters the cell during depolarization and depolarization?

depolarization : Na+

repolarization : Cl-

is blood/cell glucose high/low during fasting state?

blood: high

cell: low

are EPI/NOR stimulated in sympathetic or parasympathetic NS?

sympathetics

what do NOR/EPI do for glycogen, lipolysis, and gluconeogenesis?

glycogen: stimulate synthesis

lipolysis: stimulate

gluconeogensis: stimulate

where does cortisol synthesis occur?

smooth ER

what types of tissue are autonomic and somatic neurons found in?

autonomic: cardiac/smooth/neural tissue

somatic: skeletal tissue

what causes DNA degeneracy?

wobble rules

telomeres contain…?

short, repetitive, non-coding sequences

where do restriction enzymes cut?

palindrome sequences

introns vs exons?

introns are removed during splicing and exons remain to form mRNA

conjugation is?

bacterial sex

gene duplication is?

duplicated genes mutating freely and developing new functions over time

gene transformation is?

DNA being taken in from surrounding environment

alternative splicing?

exons are selectively included/excluded to create unique mRNA patterns from the same gene

western vs northern blot analyses

western: protein

northern: RNA

explain the steps of the sliding filament model

1. Ca binds to remove tropomyosin off of active site

2. ADP+P are present and cross bridge formation occurs

3. P leaves causing the power stroke

4. ADP leaves

5. ATP binds and detaches myosin & actin from one another

6. ATP is hydrolyzed to ADP+P again

when is a zone of inhibition formed?

when bacteria are susceptible to an antibiotic

what is the order of egg to embryo development?

1. Egg

   1. fertilization

2. zygote

   1. morula formation

3. morula

   1. blastulation

4. blastocysts

   1. gastrolation

5. gastrula

   1. neuralation

6. embryo

does sperm require high or low cytoplasm levels?

low

sperm formation steps?

1. spermatogonium

2. spermatocyte

3. spermatid

4. spermatozoon

molecular geometry of compound w/ steric #2?

linear (180)

molecular geometry of compound w/ steric #3?

trigonal planar (120)

molecular geometry of compound w/ steric #4?

tetrahedral (109.5)

molecular geometry of compound w/ steric #5?

trigonal bipyramidal (90,120)

molecular geometry of compound w/ steric #6?

octahedral (90)

electron geometry of compound w/ steric #3 & 1LP?

bent (<120)

electron geometry of compound w/ steric #4 & 1LP?

trigonal pyramidal (<109)

electron geometry of compound w/ steric #4 & 2LP?

bent (< <109)

electron geometry of compound w/ steric #5 & 1LP?

seesaw (<90, <120)

electron geometry of compound w/ steric #5 & 2LP?

T-shape (<90)

electron geometry of compound w/ steric #5 & 3LP?

linear (180)

electron geometry of compound w/ steric #6 & 1LP?

square pyramidal (<90)

electron geometry of compound w/ steric #6 & 2LP?

square planar (90)

electron geometry of compound w/ steric #6 & 3LP?

T-shape (< 90)

electron geometry of compound w/ steric #6 & 4LP?

linear (180)

what kind of bonds do salt bridges have?

ionic bonds

are hydrophobic LDFs or H bonds weaker?

hydrophobic LDFs

when writing redox reactions, what should you make the same amount in both equations?

the e- #

does a higher electrode potential want to be reduced or oxidized?

reduced

something that is reduced is a(n) __ agent?

oxidizing

what is true at the half equivalence point in a titration?

HA=A-

what is true at the equivalence point in a titration?

all solution has been reduced/oxidized

what makes a good buffer?

a weak acid & its conj. base or a wear base & its conj. acid

a strong base and strong acid form?

a neutral salt

a strong base and weak acid form?

a basic salt

a weak base and strong acid form?

an acidic salt

does back flow occur in veins or arteries?

veins

list the order of blood flow through the heart

1. deoxygenated blood enters through vena cava into right atrium

2. blood flows from right atrium to ventricle through tricuspid SL valve

3. blood flows from right ventricle into pulmonary trunk through pulmonic AV valve

4. blood flows out through pulmonary artery to be oxygenated in lung capillaries

5. blood flows back in through the pulmonary vein, now oxygenated, to the left atrium

6. blood flows from left atrium to left ventricle through bicuspid SL valve

7. blood flows from left ventricle to aorta through aortic AV valve

8. oxygenated blood flows out into body through aorta

cardiac formulas

CO = SV x HR

deltaP = CO x VR

VR = MAP/ CO

pulmonary gas exchange

water enters blood stream and co2 leaves it

what is deoxygenated blood rich/poor in?

rich in co2; poor in o2

what makes up plasma?

protein (fibrinogen, globulin, albumin) & water