B MCAT, Misc Flashcards
1
Q
Electrostatics
A
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.
2
Q
Symport vs. antiport
A
A symport moves molecules in the same direction across a membrane. An antiport moves molecules in opposite directions across a membrane.
3
Q
primary active transport vs. secondary active transport
A
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.
4
Q
Visual signal pathway
A
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
5
Q
Perception
A
Integrated information.
What the brain is doing with sensory information.
6
Q
Sensation
A
raw sensory information
7
Q
sympathetic nervous system
A
fight or flight response.
Results in increased skin conductance, increased heart rate, dilation of the pupils, increased blood glucose.
8
Q
Knee-jerk reflex arc
A
knee struck > impulse via sensory/afferent neuron > spinal cord interneuron > motor/efferent neuron > reflexive jerking motion of leg
(brain not involved)
9
Q
afferent neurons
A
sensory neurons (senses stimuli)
10
Q
efferent neurons
A
motor neuron (moves body as a result of stimuli)
11
Q
PET scan
A
In a PET scan, radioactive sugar injected and absorbed into the brain. Uptake indicates the level of activation.
ex. to measure metabolism
12
Q
CT scan
A
In a CT scan, multiple X-rays are taken from different directions to generate cross-sectional views of tissue. Measures density of tissue.
13
Q
MRI vs. fMRI
A
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.
14
Q
EEG
A
An EEG measures the electrical activity (impulses) of the brain as a whole. Does not measure specific regions.
15
Q
Hindbrain
A
The hindbrain has several functions, including managing vital functions such as breathing and digestions.
16
Q
Forebrain
A
The forebrain is associated with complex cognitive function.
17
Q
Midbrain
A
The midbrain is associated with motor movement, involuntary reflexes, auditory and visual processing.
18
Q
Cerebral Cortex
A
The cortex, or cerebral cortex, is part of the forebrain and affiliated with cognition.
19
Q
Thalamus
A
sensory relay station of the brain.
20
Q
Hypothalamus
A
Part of the brain that maintains homeostatic balance.
21
Q
Frontal Lobe
A
Part of the brain responsible for cognition.
22
Q
Hippocampus
A
Part of brain affiliated with creating memories.
23
Q
Temporal Lobe
A
The part of the brain associated with sound processing and language comprehension. It includes the auditory cortex and Wernicke’s area.
24
Q
Occipital Lobe
A
Part of brain affiliated with visual processing.
25
Parietal Lobe
Part of brain affiliated with somatosensory processing.
26
androgyny
high masculinity and high femininity
27
undifferentiated gender identity
low masculinity and low femininity
28
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.
29
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.
30
self-efficacy
self-efficacy is one's belief in their ability to succeed
31
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.
32
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?
33
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".
34
Vygotsky in a nutshell
Based on zone of proximal development.
Progression from dependence to independence.
35
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.
36
equilibrium
the rate of the forward reaction = the rate of the reverse reaction.
37
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
38
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.
39
sign conventions for energy change (Khan table)
40
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.
41
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?
42
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.
43
change in enthalpy caused by a reaction =
heat of formation
44
entropy (S)
Entropy is a measure of order or randomness.
Delta S = positive (+) when a system moves toward disorder.
45
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.
46
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.
47
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)
48
Methods of heat transfer
Radiation--heat energy transfer via electromagnetic radiation (photons). Travels in the absence of a medium. Ex. microwaves, gamma rays, UV light, Xrays.
Conduction--heat energy transfer through direct contact--collisions of molecules.
Convection--heat energy transfer through the bulk motion of liquids and gases.
49
Laws of Thermodynamics
Zeroth Law: Two bodies in thermal eqm are at the same temperature. (heat is the mechanism)
First Law: Energy cannot be created or destroyed.
Second Law: Total entropy of a system must increase to be spontaneous.
Third Law: The entropy of a pure crystal at 0 Kelvin is zero.
50
Endergonic vs. exergonic
In an endergonic reaction, products have a higher Gibbs free energy than the reactants. Delta G is positive.
In an exergonic reaction, products have a lower free energy than the reactants. Delta G is negative.
51
DNA denaturation, reannealing, and hybridization
DNA will completely denature around 95 degrees Celsius. This can break the triple Hydrogen bonds between C and G; double H bonds between A and T break at much lower temps.
Reannealing is when the two strands of DNA come back together to form the double helix again. It is a naturally occurring process, favored by the formation of the H bonds, and because it keeps the hydrophobic (N, aromatic) bases away from water.
Annealing to a complementary piece of DNA is called hybridization. Often used in the lab to identify sequences. Critical step in PCR (polymerase chain reaction).
52
Central Dogma of Biological Systems
(replication) < > DNA >>> (transcription) >>>RNA >>> (translation) >>> (protein)
53
Genetic Code
The genetic code is how cells translate mRNA into strings of amino acids in proteins.
It takes 3 nucleotide bases to specify each amino acid. The set of 3 is called a codon. The genetic code is redundant--64 codons for 20 amino acids.
54
Silent Mutation
Type of translation mutation of the genetic code; does not affect the proteins.
55
Missense Mutation
A mutation in translation of the genetic code that results in a codon coding for the wrong protein.
56
Nonsense Mutation
A mutation in translation of the genetic code that involves the substitution of a base. Could result in a premature stop codon or a nonfunctional protein.
57
Frameshift Mutation
A mutation in translation of the genetic code that involves the deletion or insertion of a base.
58
What s the principle the gel electrophoresis is based on for the separation of DNA?
DNA carries a negative charge because of the phosphate groups on the sugar-phosphate backbone. So, DNA will migrate toward a positively-charged electrode--the anode in electrophoresis (types of electrollic cells).
59
What determines the order by which tRNAs bring Amino Acids to mRNA?
The order is determined by the attraction between the codon of the mRNA and the anticodon of the tRNA, which specifies the amino acid that the tRNA carries.
60
Selective Transcription
Selective transcription (selective expression) regulates cell differentiation and specialization by transcribing only the genes needed for the particular cell function.
Specific genes are turned on in certain types of cells, and others are turned off.
61
Autonomic Nervous System
Autonomic nervous system controls involuntary actions such as breathing, heart rate, and endocrine control.
62
Somatic Nervous System
The somatic nervous system is responsible for voluntary action.
63
Sympathetic Nervous System
The sympathetic nervous system is responsible for the involuntary stimulation of the "fight or flight" response; releases epinephrine and norepinephrine to increase heart rate.
64
Parasympathetic Nervous System
The parasympathetic nervous system is responsible for the involuntary stimulation of the "rest and digest" response; releases acetylcholine to decrease heart rate.
65
Process of Summation
Adding things together
66
What is a hormone?
A chemical messenger used by glands to communicate (act on) tissues and cells to facilitate various biological functions.
Can be a protein or a steroid. Protein hormones generally act on cell membranes. Steroid hormones generally act directly on the nucleus of the cell.
Direct hormones act on cells and tissues. Tropic hormones act on glands.
67
Stages of Cognitive Development, by Jean Piaget
Sensory Motor--Using very physical sensory and motor skills, ~1-2 years.
Pre-Operational Stage--Marked by onset of object permanence. Symbolic thinking. Gestures have meaning.
Concrete Operation Stage--Marked by understanding of "conservation" (short, wide glass of OJ holds the same amount as tall skinny glass). Less egocentric; understanding that others might have different views of the same object. Logic develops. ~age 7.
Formal Operational Stage--Understand hypothetical events and use them for problem-solving. Abstract events, emotions, success and failures, etc. ~11+
68
Vygotsky's View on Cognitive Development
Vygotsky believed that socio-cultural events and parenting styles will affect cognitive development. Thought the same benchmarks may be achieved, they may happen at different paces and in different ways. Will develop different skills that affect overall personality in the future.
69
Problem-Solving Methods of Cognition
and Heuristics
1. Trial and error
2. Algorithms (methodically sorting)
3. Deductive Reasoning (top-down)
4. Inductive Reasoning (bottom-up)
Heuristics is finding short cuts.
exs:
-horn and halo effect (ex. sports team judgements).
-"gut" feeling.
-bias.
70
Categories of consciousness-altering drugs
Depressants
Stimulants
Opiates
Hallucinogens
Important to address sleep disorders and addiction.
71
Components of Language
Phonology--sounds
Morphemes--structure, building blocks of words, ex. prefixes
Syntax--How words are arranged into sentences
Semantics--association and meaning of words
Pragmatics--The study of the intentions and use of words
72
Area of brain associated with speech production
Broca's Area is associated with speech production.
vs. Wernicke's area associated with language comprehension. Two diff areas of brain connected by the Arcuate Fasciculus.
73
Wernicke's Area
Wernicke's Area is associated with language comprehension.
vs. Broca's Area associated with speech production. Two diff areas of the brain connected by the Arcuate Fasciculus.
74
Aphasia
Aphasia is a deficit of language comprehension or production.
75
Standford Binet IQ Test Scale
Determines mental age and compares it to physical age. Base score of 100 if they align perfectly.
76
Gardner's Theory of Multiple Intelligences (7 types)
1. Linguistic
2. Logical-Mathematical
3. Musical
4. Visual-Spatial
5. Bodily-Kinesthetic
6. Interpersonal
7. Intrapersonal
77
Retrograde amnesia vs. anterograde amnesia vs. confabulation
Retrograde amnesia is loss of memory that occurred in the past.
Anterograde amnesia is inability to form new memories.
Confabulation is memory error in which gaps are filled in with fabricated information. Unique to Korsakoff's Syndrome.
78
Fundamental Attribution Theory
The bias tenancy, especially in groups, to attribute failure to individuals' negative personal characteristics rather than situational aspects.
79
only two ways to transfer energy
forces or light.
80
amphoteric
a molecule that can act as both an acid and a base. Ex. Water
81
pH
(power of hydrogen)
pOH
(power of hydroxide)
mathematically, pH = -log(H+)
To reverse back to standard (non-logarithmic) concentration, multiply the pH by -1, then take both to a base of 10. So...
-1(pH=-log(H+))
-pH=log(H+)
10^-pH=10^(log(H+))
Because pH is a logarithmic scale, a one-unit change in PH could represent a ten-fold change in acidity.
-pOH=log(OH-)
pH + pOH = 14
82
Equilibrium Constants, Mathematically
Water is neutral at pH of 7, so
Kw=[H+][OH-]=(10^-7)(10^-7)=10^-14
Ka x Kb = Kw = 10^-14
So,
-log((Ka)(Kb))=-log(10^-14)
So,
-log(Ka)+-log(Kb)=14
So,
pKa + pKb = 14
pH + pOH=14
83
EQM constants are at standard temperature and pressure (25 degrees Celsius, 1 ATM). What happens if you change conditions?
If you increase temp (add heat to reactants), then the EQM shifts toward products--Keq gets larger.
For water, a larger Kw = a smaller pH, meaning that the neutral pH point, where [H+] = [OH-] will be lower.
84
Significance of pH and pOH vs. pKa and pKb...
pH and pOH allow us to quantify the total concentration of hydrogen or hydroxide ions in solution.
pKa and pKb allow us to quantify the relative acidity or basicity of a specific molecule.
85
memorize strong acids and bases
86
A salt refers to...
A salt refers to any substance containing ionic interactions between cations and anions.
So, a reaction of an acid + base forms water and a salt.
87
To identify a strong acid, look for...
a stable, weak conjugate base.
88
To determine the number of stereoisomers of a molecule, use the _______ rule.
To determine the number of stereoisomers of a molecule, use the 2^n rule, in which n is the number of chiral carbons in the molecule.
89
Enzyme classifications
Oxidoreductase
Isomerase
Lyase
Transferase
Oxidoreductase enzymes catalyze REDOX reactions.
Isomerase enzymes catalyze the change between stereo- (configurational) isomers. (ex. maleate isomerase enzyme is responsible for cis-trans isomerization of maleate to fumarate, which is used as an intermediate in the citric acid cycle.
Lyase enzymes catalyze the breaking of bonds by means other than hydrolysis.
Transferase enzymes catalyze the transfer of a particular group from one molecule to another.
90
sound
Sound is compressions and rarefactions moving through a medium.
Sound most commonly measured in deci-bels.
decibels = 10(log(I/I naught))
I/I naught is the ratio of the intensity of a given sound / the reference of intensity of the quietest sound a human can hear, 10^-2.
Wave characteristics (e.g. intensity) do not change the speed of the wave. Only the medium that the wave is traveling through can affect its speed.
Two characteristics of mediums that affects sound.
1) Bulk modulus. How close the particles are in the medium. Wave can propagate faster in solids than liquids or gases because the sound is traveling based on the distance between particles.
2) Density. How much does the matter resist change in motion. More mass = more resistance to change in motion--the law of inertia. Less dense means faster traveling sound (i.e. inhaling helium gas making a high-pitched voice in comparison to air).
Frequency stays the same. Pitch is how we perceive a waves frequency. Human hearing ranges from about 20 Hertz to 20,000 Hz. Below 20 = Infrasonic waves
Above 20,000 Hz = Ultrasonic waves
Frequency = velocity / wavelength
91
Doppler effect equation for measuring the perceived frequency of sound of a moving sound source.
f'=(v of sound +/- v of detector) / (v of sound +/- v of source)
92
Index of refraction
Index of refraction = speed of light in a vacuum / speed of light in medium
This is a ratio, with a vacuum being fastest at value of 1.0. So, the slower light travels in a medium, the higher the index of refraction will be.
Dispersion = Index of refraction of a material is slightly different based on the color of the light going into it. Violet travels slower, bends more.
For light going between mediums, whichever medium (i.e. side) has a larger index of refraction will have a smaller angle, and visa versa.
93
real vs. virtual images
Real images occur when light comes together.
An inverted image can only be a real image.
94
Equation to calculate the energy of a photon
E = hf
h = Plank's constant
f = frequency in Hz
95
Mass Defect
The mass of an atom is slightly less than the combined mass of its protons and neutrons because a small amount of mass is used for binding energy to hold the nucleus together. This is known as the mass defect.
96
Alpha Decay
Alpha decay results in an atom with an atomic number 2 less than the starting element, and atomic mass 4 less than the starting element.
97
Gamma Decay
emission of high-energy gamma rays (photons), resulting in a lower energy of parent nucleus. NO change to atomic number and NO change to mass number.
98
To calculate half life...
To calculate the half life of a radioactive particle, divide to find the number of half lives; then, take (0.5)^n.
Ex. Given element has 30 yr half life, how much is left after 150 years?
150/30=5
0.5^5 = 1/32
.5^1=.5
.5*.5=1/4
1/4*1/2=1/8
1/8*1/2=1/16
1/6*1/2=1/32
99
How many atoms are in a 4 mol sample of a given element?
4mol *(6.02*10^23 atoms/1mol)
= 2.4*10^24 atoms
(Avogadro's Number)
100
What is the mass of a sample of iron containing 1.2*10^24 atoms?
(Iron's molar mass is 55.85g/mol.)
1.2*10^24atoms / 6.02*10^23 atoms/mol = 2 mol
2mol * 55.85 g/mol= 112 g
101
Beta minus decay
Beta minus decay results in an atom with the SAME atomic mass, and an atomic number ONE higher than the original.
102
Blood pressure control
Blood pressure is controlled by the kidney via the renin>angiotensin>aldosterone pathway.
Aldosterone is the primary hormone used to increase blood pressure. It causes the body to retain salt, and with it water, to maintain osmotic balance in the blood. More fluid within the same space increases pressure. Then, the posterior pituitary releases antidiuretic hormone (ADH) to maintain blood osmolality, which is usually a indication of dehydration. It causes water reabsorption from the collecting duct to correct this, resulting in increase in blood volume and more increase in blood pressure.
103
Paul Ekman's 7 universal facially expressed emotions
happiness, sadness, contempt, disgust, surprise, fear, anger
104
Electrostatic Force (N)
F = kQq / r^2
electrostatic force = k * source of electric field Q * charge experiencing field q
/ radius ^2 (distance apart--consider + or - , opposite or same charge)
105
Electrostatic Field (N/C)
E = F / q
Electrostatic field = Force / charge experiencing the field (q)
Newtons per Columb
106
Electric Potential Energy
and
Electric Potential
Electric Potential Energy
U = f*r
OR
U = kQq / r
Electric Potential (Voltage)
(standardized energy per unit charge. Voltage tells us what a energy a second charge will have.)
V=U/Q
OR
V=kQ/r
V = J/C
OR
V=E*r
V=Ed
107
Electric fields point from ______ potentials to ________.
Negative charge moves _______ electric field lines.
Positive charge moves _______electric field lines.
Electric fields point from higher potentials to lower potentials (+ to -).
Negative charge moves against electric field lines.
Positive charge moves with electric field lines.
108
Ohm's Law
V=iR
109
kinase
an enzyme that catalyzes phosphorylation
110
dehydrogenase
An enzyme that is involved in REDOX reactions. Dehydrogenase oxidizes, or adds a hydride molecule to something else (ex. to NAD+ or FAD in the citric acid cycle).
111
3 enzymes that catalyze the irreversible steps of glycolysis
1) hexokinase
2) phosphofructokinase
10) pyruvate kinase
A kinase enzyme catalyzes phosphorylation, though this is reversible in some reactions.
112
Metabolism, catabolism, and anabolism
Anabolism and catabolism are the two broad classes of biochemical reactions that make up metabolism.
Anabolism is the synthesis of complex molecules from simpler ones. These chemical reactions require energy.
Catabolism is the breakdown of complex molecules into simpler ones.
113
Catabolism under anaerobic conditions in humans
Under hypoxic conditions, the body may not have enough oxygen to meet energy demands, and anerobic metabolism kicks in in the form of lactic acid fermentation.
Reduces pyruvate to lactate, and oxidizes NADH to NAD+, so that glycolysis may continue. NAD+ replaces O as electron-acceptor.
While glycolysis and anerobic fermentation can continue in the cytosol, the Citric Acid Cycle and Oxidative Phosphorylation (in the mitochondria) cannot proceed.
114
energy inputs and outputs
115
Isomerase
An enzyme that catalyzes isomerization--same chemical formula, different arrangement of atoms.
116
How many molecules of CO2 are produced from one molecule of glucose going through glycolysis and the citric acid cycle?
=6
All 6 carbons from a single molecule of glucose are fully oxidized into CO2 during glycolysis and the citric acid cycle.
117
Rate law
1st order means that there is one reactant that's concentration is affecting products. 2nd order means 2 reactants, etc.
Rate=k[reactant]
(NOTE: Though they are closely related, don't confuse "k" referring to kinetics with eqm "K" referring to thermodynamics. For k, looking at reactants only; don't worry about products.)
At Keq, forward rxn (A) rate = reverse rxn (B) rate.
kf[A]=kr[B]
kf/kr = [B]/[A] = Keq
Keq=kf/kr
118
How to calculate oxidation state
Count bonds. All bonds to more electronegative elements add a + to the oxidation state.
