MCAT Review Sheet Flashcards
what can cause denaturation
heat and solutes
myosin is a motor or structural protein?
motor
kinesin is a motor or structural protein?
motor
collagen is a motor or structural protein?
structural
actin is a motor or structural protein?
structural
dynein is a motor or structural protein?
motor
keratin is a motor or structural protein?
structural
elastin is a motor or structural protein?
structural
tubulin is a motor or structural protein?
structural
what do binding proteins do?
bind a specific substrate, either to sequester it in the body or hold its concentration at steady state
what do cell adhesion molecules (CAMs) do
bind cells to other cells or surfaces
what do antibodies target
antigens, which is a protein on the surface of a pathogen or toxin
ion channels
used for regulating ion flow into or out of a cell
ligases
responsible for joining two large biomolecules, often the same type
isomerases
catalyze the interconversion of isomers, including both constitutional and stereoisomers
lyases
catalyze cleavage without the addition of water and without transfer of electrons
the reverse reaction (synthesis) is usually more biologically important
hydrolases
catalyzes cleavage with the addition of water
oxidoreductases
catalyze oxidation-reduction reactions that involve the transfer of electrons
transferases
move a functional group from one molecule to another
do enzymes alter free energy or enthalpy
neither
what do enzymes do
lower activation energy
what are trioses
3 carbon sugars
what are tetroses
4 carbon sugars
what is the difference between paramagnetic and diamagnetic?
p: electrons are NOT paired; they react with magnetic field
d: electrons are paired; less likely to react with magnetic field
think: di=pair (like diastereomers)
what is nuclear binding energy
energy needed to disassemble or assemble a nucleus
in nuclear binding energy, what kind of charge is associated with disassemble and assemble?
D: +charge because it uses energy
A: -charge because it gives off energy
what happens in 1,4-B linkage?
H2O is always lost
if there is a lower energy transition state, does that mean it is less or more stable
more stable
what do catalyst at the end of the reaction do
they always go back to the original form
left brain vs right brain
left: logic, linguistic etc.
right: colorful and creative
what kind of bonds does cysteine have?
disulfide bond
what makes and breaks disulfide bonds
bonds are made by oxidation and broken by reduction
in ideal gas, what is the fixed molar volume
22.4L per mole
what is the specific heat capacity of water
4.2
what is the resting membrane potential?
-70
equation of power
power= force x velocity
when an impurity is introduced, what happens to the melting point?
decreases
in a graph, what does repolarization, hyperpolarization, and depolarization mean
depol: going up on the curve
repol: going down on the curve
hyperpol: the deep plunge beneath the dotted line
in D vs L amino acids, which goes right and left? think in terms of fischer projections
NH3+ goes left for L (L for left)
NH3+ goes right for D
in a fischer projection, where is the position of the R and what about the carboxylic acid?
carboxylic is on top and R on bottom
think:R on bottom(bottom=rear end)
what is the difference between nucleosides and nucleotides
sides: contain 5 carbon sugar bound to a nitrogenous base
tides: nucleosides with 1-3 phosphate groups
what is the watson-crick model
DNA is made up of alternating sugars and phosphate groups and is always read 5’-3’
two strands with antiparallel polarity
wound into a double helix
which nitrogenous bases are purines?
adenosine and guanine
which nitrogenous bases are pyrimidines?
cystine, thymine, uracil
chargaffs rules state?
a=t
g=c
no more no less
heterochromatin vs euchromatin
h: dense, transcriptionally silent DNA
e: less dense, transcriptionally active DNA
DNA leading strand vs lagging strand
leading: requires only 1 primer
lagging: requires many primers
what is recombinant DNA
DNA composed of nucleotides from 2 different sources
what is the central dogma
DNA->RNA->proteins
in genetic code, what is the initiation and termination codons
start: AUG
stop: UAA, UGA, UAG
what is the result of a silent mutation
no effect on protein synthesis
what is the result of a nonsense(truncation) mutation
produce a premature stop codon
what is the result of missense mutations
produce codon that codes for different amino acid
what is the result of frameshift mutations
result from nucleotide addition or deletion and change the reading frame of subsequent codons
what are the three things that are different in RNA from DNA
- substitute ribose sugar for deoxyribose
- substitute uracil for thymine
- single stranded instead of double
what are the three steps of transcription?
- helicase and topoisomerase unwind DNA double helix
- RNA polymerase 2 binds to TATA box within promoter
- hnRNA synthesized from DNA template
what does alternative splicing do
combines different exons to acquire different gene products
what are the three stages of translation
initiation
elongation
termination
where does translation occur at
ribosome
what is the difference between promoters and enhancers
p: within 25 base pairs of the transcription start site
e: more than 25 base pairs away from the transcription start site
what is osmotic pressure
pressure applied to a pure solvent to prevent osmosis
what is osmosis
diffusion of water across a selectively permeable membrane
what is facilitated diffusion
uses transport proteins to move impermeable solutes across the cell membrane
where does glycolysis occur? does it need O2?
occurs in the cytoplasm of all cells
does not require O2
what is the end result of glycolysis
2 ATP per glucose
list the steps of citric acid cycle
Can I Keep Selling Sex For Money Officer?
start with pyruvate and acetyl-coA
citrate
isocitrate
Ketoglutarate
Succinyl-CoA
Succinate
Fumarate
Malate
Oxaloacetate
what is the proton motive force
electrochemical gradient generated by the electron transport chain across the inner mitochondrial membrane
glycogenesis
glycogen synthesis: building of glycogen using 2 main enzymes - glycogen synthase and branching enzyme
glycogenolysis
breakdown of glycogen using 2 main enzymes - glycogen phosphorylase and debranching enzyme
gluconeogenesis occurs where?
occurs in both cytoplasm and mitochondria, predominantly in the liver
what is gluconeogenesis
reverse of glycolysis
what are the layers of the skin
Come Lets Get Sun Burnt
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basalis
what is ectoderm
nervous system, epidermine, lens of eye, inner ear
endoderm
lining of digestive tract, lungs, liver and pancreas