B MCAT, Misc Flashcards
Electrostatics
Electrostatics mediates interactions between macromolecules and polar and ionic components of their environment, including water, protons, and salts, and they play a fundamental role in the physiological regulation of many proteins.
Symport vs. antiport
A symport moves molecules in the same direction across a membrane. An antiport moves molecules in opposite directions across a membrane.
primary active transport vs. secondary active transport
Primary active transport uses energy molecules, such as ATP, to move molecules across a membrane.
Secondary active transport, or coupled transport, uses the energy generated from movement of one molecule down its concentration gradient to move another molecule against its concentration gradient.
Visual signal pathway
Light enters eye through cornea> aqueous humor (transparent substance) > iris (contracts or dilates to adjust to light > lens > vitreous humor > hits rod and cone cells of the retina > optic nerve > lateral geniculate nucleus (of thalamus) > occipital lobe
Perception
Integrated information.
What the brain is doing with sensory information.
Sensation
raw sensory information
sympathetic nervous system
fight or flight response.
Results in increased skin conductance, increased heart rate, dilation of the pupils, increased blood glucose.
Knee-jerk reflex arc
knee struck > impulse via sensory/afferent neuron > spinal cord interneuron > motor/efferent neuron > reflexive jerking motion of leg
(brain not involved)
afferent neurons
sensory neurons (senses stimuli)
efferent neurons
motor neuron (moves body as a result of stimuli)
PET scan
In a PET scan, radioactive sugar injected and absorbed into the brain. Uptake indicates the level of activation.
ex. to measure metabolism
CT scan
In a CT scan, multiple X-rays are taken from different directions to generate cross-sectional views of tissue. Measures density of tissue.
MRI vs. fMRI
Generally, MRI measures density of protons in tissue (i.e. water) via proton NMR.
In the brain, MRI scans show the structure of the brain.
fMRI scans (functional MRI scans) measure activity of the brain via changes in blood flow.
EEG
An EEG measures the electrical activity (impulses) of the brain as a whole. Does not measure specific regions.
Hindbrain
The hindbrain has several functions, including managing vital functions such as breathing and digestions.
Forebrain
The forebrain is associated with complex cognitive function.
Midbrain
The midbrain is associated with motor movement, involuntary reflexes, auditory and visual processing.
Cerebral Cortex
The cortex, or cerebral cortex, is part of the forebrain and affiliated with cognition.
Thalamus
sensory relay station of the brain.
Hypothalamus
Part of the brain that maintains homeostatic balance.
Frontal Lobe
Part of the brain responsible for cognition.
Hippocampus
Part of brain affiliated with creating memories.
Temporal Lobe
The part of the brain associated with sound processing and language comprehension. It includes the auditory cortex and Wernicke’s area.
Occipital Lobe
Part of brain affiliated with visual processing.
Parietal Lobe
Part of brain affiliated with somatosensory processing.
androgyny
high masculinity and high femininity
undifferentiated gender identity
low masculinity and low femininity
hierarchy of salience
the way in which we organize our identities to allow a situation to dictate which identity holds the most importance in any given moment.
self-discrepancy theory
Self-discrepancy theory says that we have three parts to our self–
ideal self–who we want to be
ought self–who we think others want us to be
actual self–how we are
The closer these three parts are to each other, the higher one’s self-esteem.
self-efficacy
self-efficacy is one’s belief in their ability to succeed
Freud in a nutshell
unconscious self rules.
5 stages to gain gratification:
oral (infant)
anal (1-3 years)
phallic (3-5)
latency (6-11)
genital (12-20)
internal conflicts, negative resolution results in fixation.
Erickson in a nutshell
Internal conflict phases throughout lifespan.
Can I trust the world?
Is it okay for me to be me?
Is it okay for me to do and feel?
Can I make it in the world?
Who am I; who can I be?
Can I love?
Can I make my life count?
Is it okay to have been me?
Kohlberg in a nutshell
Based on moral question of Heinz dilemma and what the reasoning was behind study participant’s answers.
Mr. Heinz’s wife is sick and he can afford the life saving drugs.
Continuum pyramid from “punishment and obedience” up to “universal ethics standards”.
Vygotsky in a nutshell
Based on zone of proximal development.
Progression from dependence to independence.
Reaction rate laws
Rate law for any particular reaction:
rate = rate constant (K) x [concentration of slow step reactant]^(stoichiometry, number of molecules of that reactant needed)
stoichiometry (power raised) of slow step(s), all added together) is what is used to label the “order” of the reaction.
2 molecules of slow reactant = ^2 = first order reaction = if we double the concentration of reactant in start, we expect quadruple the number of collisions.
equilibrium
the rate of the forward reaction = the rate of the reverse reaction.
Keq vs. Q
Both Keq and Q are the RATIO of [products]/[reactants].
Keq = [P]/[R] when equilibrium is reached.
Equilibrium expressions do NOT include pure liquids or pure solids.
Q=[P]/[R] at a moment in time.
Number of atoms indicate exponents.
Q>K indicates reactants will be favored.
Q<K indicates products will be favored.
sign conventions for energy change
delta U = energy change in a system.
Delta U = Heat (Q) - Work (W)
System transfers heat energy (to environment) = negative (-) energy change
Heat energy enters system (from environment) = positive (+) energy change
System expands, then energy change due to work = negative (-)
System is compressed, then energy change due to work = positive (+)
Ex. if a gas is compressed, then the system should be gaining energy from that work.
sign conventions for energy change (Khan table)
Components of Enthalpy (H)
Components of enthalpy (H) =
1) Internal energy; the sum of all potential and kinetic energy of a system.
2) Energy necessary for a system to take up space (since expanding system requires energy). =Vol (V) of system x pressure (P) of environment
So…
H=U+PV
Typically measure delta H, so you choose the starting point and calculation focuses on the change in enthalpy.
chemical bonds and energy
Breaking bonds converts kinetic energy into potential energy; (other than noble gases) it takes energy to move atoms apart.
Making bonds releases energy (converts potential energy into kinetic energy).
Question of spontaneity is, which energy value is greater, that to break the bonds or that released when the new bonds are formed?
Heat of reaction, formation of water
O2(g) + 2H2 —> 2H2O + energy
heat of formation, delta H = negative, since energy is released by the reaction/system.
Potential energy becomes kinetic energy.
Increases the thermal energy, the temperature of the system = exothermic.
This energy often leaves the system as heat–radiation (light), conduction, and convection.
change in enthalpy caused by a reaction =
heat of formation
entropy (S)
Entropy is a measure of order or randomness.
Delta S = positive (+) when a system moves toward disorder.
entropy (S)
Entropy is a measure of order or randomness.
Delta S = positive (+) when a system moves toward disorder.
More disorder = more degrees of freedom.
ex. Hydrogen gradient in the electron transport chain. H+ want to move through chain toward a less ordered state to gain entropy. The entropy gained by the movement of H+ is higher than the Storing ATP requires less order than storing the H+.
**Also look at number of Moles of P and R. Fewer moles, more bonds = decrease in entropy.
**Pay attn to states of matter. Gases have greatest entropy.
order of reactions, rate laws
A rate law is the rate constant (k) multiplied by the product of the concentration of the reactants of the slow step(s). The stoicheometry coefficients of the reactants are the exponents.
When given reaction and trying to determine order, consider how many fold increase is observed per reactant.
Ex. 2x reactant concentration with observed doubling of products = 2R^1, first order.
Increasing concentration of R with no effect on P = R^0 (zeroth order rxn).
If you have two reactants, add the order of each to get the total order of reaction.
Ex. R^1 + R^1 = total reaction order is (1+1) second order.
Rate laws are based on the sum of the orders of the rate-determining reactants.
Hess’s Law, calculating enthalpy of a reaction
Total delta H = (sum of delta H of formation of products) minus (sum of delta H of formation of reactants)