Missed Q's
Based on the structure of sphingomyelin, which of the following structures accurately represents choline? A. (CH3)3N+CH2CH2OH Correct Answer B. (CH3)3N+CH2CH2COO- C. (CH3)3NCH2CH2OPO3- D. (CH3)3N+CH2CH2OPO4CH2OH
A. The passage states that the phosphoric acid substituent is esterified with the amino alcohol, choline. The structure in choice A represents the amino alcohol that is esterified.
Microfilaments are composed of
Actin
STP
0C, 1 atm (101.3 kPa)
man runining 2 kilometers in 12 minutes does how much work
0J the man runs a net distance of 0m bc he ran on a treadmil
sources of genetic diversity
1. NS acts on genetic diversity to alter allele frequencies, however it does NOT indroduce genetic diversity 2. mutations 3. sexual reproduction: mendel's principles of segregation and law of independent assortment 4. sexual reproduction: recombination in meiosis!
all ideal gases at STP will ocupy
22.4 L per mole of gas molecules
exponential increase of DNA sequence (PCR)
2^n
glucose transporter subtypes
GLUT2 and GLUT4 GLUT2 -- liver and pancreatic cells GLUT4 ---- adipose tissue TO INCREASE GLUCOSE UPTAKE, INCREASE NUMBER OF GLUT4 RECEPTORS (iinsulin signalling causes this)
how many times does a GPCR pass through membrane
GPCR pass through plasma membrane seven times THEY HAVE SEVEN TRANSMEMBRANE DOMAINS
Gtpases, like Rac, are activated by
GTP
when pH = pKa
HA = A-
cDNA
In genetics, complementary DNA (cDNA) is double-stranded DNA synthesized from a single stranded RNA
cdna
In genetics, complementary DNA (cDNA) is double-stranded DNA synthesized from a single stranded RNA (e.g., messenger RNA (mRNA) or microRNA (microRNA)) template in a reaction catalysed by the enzyme reverse transcriptase. cDNA is often used to clone eukaryotic genes in prokaryotes.
What AAs can form disulfide bonds
Disulfide bonds in proteins are formed between the thiol groups of cysteine residues by the process of oxidative folding. The other sulfur-containing amino acid, methionine, cannot form disulfide bonds.
Voltage (V) is equivalent to
J/C
Which of the following peptides is most likely to form a covalently bonded dimer
Look for a peptide sequence with cysteine (C) as it is capable of forming disulfide bonds
Hyperbolic
Michaelis-Menten, Inverse relationships
neutralization equation
Molar A X Volume A = Molar B X Volume B
SA node vs AV node
SA node = where the impulse of contraction of the heart originates (situated in the RA close to the point of entry of the vena cava) AV node = receives impulse from SA node and transmits it to ventricles. receives action potentials from SA node and passes them along delating so that ventricles can fill before contracting
rate of diffusion in facilitative diffusion is limited by
NUMBER OF INTEGRAL PROTEINS
When given only Km and Vmax, how do you determine catalytic efficiency?
The efficiency of an enzyme is measured by kcat / Km ratio. Since Vmax = kcat [ E ], assuming a constant [E], kcat is directly related to the vmax.
in studies evaluating differences in treatment outcomes, the treatment and control groups must be
ON average, comparagble at the beginning baseline charactereistics (ex. blood pH, blood bicarbonate concentration) must be equal
Ovarian cells are which type of tissue, while Osteoclasts are which type 1. epithelial 2. connective 3. nervous
Ovarian cells are epithelial Osteoclasts are connective
bernoullis equation
P + 1/2pv^2 + pgh = constant
van der waals equation
P = (nRT/V-nb) - (n^2a/V^2) *b for bounce, a for attraction V-nb = repulsion term (The greater b is, the more repulsion, which leads to greater pressure) n^2a = attraction term (the greater a is, the more attraction, which leads to lower pressure)
what does PCR reqire
PCR amplifies specific sequences of DNA PCR requires DNA primers, nucleotides, dna polymerase, and a template strand required conditions 1. denature = 95 degrees 2. anneal = 60 degrees 3. 72 degrees for taq polymerase (heat resistant)
Electrochemical gradient responsible for ATP synthesis is formed when protons are pushed into...
The intermembrane space
urbanization
Urbanization is a population shift from rural to urban areas, "the gradual increase in the proportion of people living in urban areas", and the ways in which each society adapts to the change.
adult humans generally dont have enzymes for alpha or beta linkages of starch???
adult humans are generally unable to cleave BETA linkages
aldose vs ketose
aldose = sugar with an aldehyde group ketose = sugar with a ketone group
in eukaryotes, all amino acids (except cysteine) are
all amino acids are L (which means that the amino group is on the left in a fischer projection) all amino acids except cysteine are S absolute configuration
Glycogen linkage
alpha 1, 4 linear and alpha 1,6 branched
methanol is very easily made into
anhydrous methanol during the distillation process, all of the water can be removed. this is beneficial bc water hinders esterification rxns, by bonding to the carbonyl where the alcohol should
graham's laww
applies to both difusion and effusion rate1 / rate2 = sqrt (M2 / M1) **the lighter gas will travel faster, and the gases will meet at a point that is farther from the end of the lighter gas
charles' law
at constant pressure V1/T1 = V2/T2
boyle's law
at constant temperature: P1V1 = P2V2
when and why do real gases deviate from ideal behavior
at low temperature and high pressure real gases deviate from ideal behavior bc the size of the molecules and intermolecular forces become significant
autotrophs vs heterotrophs
autotrophs use CO2 as their sole carbon source heterotrophs use organic molecules from eating other organisms as their carbon source
saponification
base catalyzed hydrolysis of ester triglycerides to 3 fatty acids and glycerol
biological perspective
based on biological inheritance
non competitive inhibitors
bind non covalently to an enzyme at a spot other than the active site and change the conformation of the enzye -bind to enzyme if it is bound to substrate or not, with EQUAL affinity -substrate cannot outcompete the inhibitor (even if inc substrate concnetration super high) -
uncompetitive inhibitors
bind noncovalently to an enzyme at a spot other than the active site and change the conformation of the enzyme -ONLY bind to enzyme if it is bound to substrate (and keeps the substrate bound to the enzyme) -cannot outcompete the inhibitor with high concentrations
GPCR
binding to GPCR activates many G-proteins each g=protein activates many adenylyl cyclase enzymes each adenylyl cyclase makes lots of cAMP from ATP each cAMP activates many cAMP-dPK each cAMP-dPK phsohphorylates many enzymes GPROTEINS CAN BE INBITORY OR STIMULATORY (Gi or Gs)
rood blood cell production occurs in
bone marrow
thoracic cavity
chest cavity - chamber of the body that is protected by the rib cage
the liver synthesizes bile from
cholesterol
a suspected osmolyte is added in excess to a solution containing chromic acid, and the resulting product is identified as a terminal organic acid phenol ether aldehyde ester
chromic acid is a common ox agent, so the rxn described is a redox rxn. begin by identifying which types of molecules can be oxidized to organic acids: aldehydes and alcohols phenols is inccorect because even though it has a hydroxyl group, it is not considered an alcohol. furthermore, a phenol cannot be oxidized due to the disruption of aromaticity
what protease will preferentially cleave peptide bonds next to aromatic amino acids
chymotrypsin preferentially cleaves peptide bonds next to large hydrophobic amino acids (tyrosine, phenylalanine, tryptophan..)
cilia vs flagella (euk)
cilia = hairs on cell surface which move fluid apst the cell (ex. respiratory tract) flagella = large tail which moves cell by wiggling (made by microtubules in euk and flagellum in prok)
restriction enzymes
cleave DNA! - DNA is targeted by RESTRICTION ENZYMES with no methylation - cut at only certain sequences called RESTRICTION SITES -restriction sites are generally palindromic: read the same way forward and backwards
lac operon inducible system
codes for enzymes that allow for the import and catabolism of lactose operator: downstream (towards 3') to the promotor, binding site for repressor repressor protein is inactivated by lactose, transcription is ACTIVATED in the presence of lactose POSITIVE CONTROL SYSTEM
sound intensity formula
dB = 10log (I/Io) where Io = 1X10^-12
speed of sound depends on.... compare phases
depends on the MEDIUM sound> liquid> gas v = sqrt (bulk modulus / density)
osmotic pressure
determines whether and d in what direction osmosis will occur solvent will move from an area with low osmotic pressure value to an area with high osmotic pressure value
dna sequences use
dideoxyribonucleotides, which terminate the DNA chain because they lack a 3' - OH group the resulting fragments can be separated by gel electrophoresis, and the sequence can be read directly from the gel
observational error
difference between a measured value and its true value
anomers
different forms of the same carbohydrate epimer that differs at the anomeric carbon chiral center ex. alpha-glucose and beta-glucose
ex of catalytic receptors
enzymatic active site on the extracellular side of the membrane ex = receptro tyrosine kinase
restriction endonuclease
enzyme prodcued chiefly by certain bacteria that have the property of cleaving DNA molecules at or near a specific sequence of bases
fatty acids spontaneously form phosopholipids spnontaneluosly form
fa = miscelles phospholipids = lipid bilayers
glucose transport in relation to Na+
glucose transport in cells is independent of Na+ glucose transport in digestive tract is dependent on Na+
proteins that are completed on free ribosomes are destined to
go to mitochondria, nucleus or cytoplasm
a reducing sugar
has an anomeric carbon that is free to become OXIDIZED (it will have a hemiacetal!!!) **this allows Cu2+ or Ag+ to be reduced!! (cu2+ turns from blue to red, Ag forms silver mirror lining in benedicts and tollens, respectively)
what type of cell is infected by HIV
helper t cells
when are hemiketals formed? hemiacetals?
hemiketals = the result of a nucleophilic addition of a hydroxyl donated by an alcohol group to a ketone carbonyl group hemiacetals = when water addds to the carboxylic acid
the binding of oxygen to hemoglobin does not follow the rules of michaelis menten because
hemoglobin exhibits allosteric effects the key assumption on which michaelis-menten kinetics are based is that there is ONLY ONE active site capable of binding substratee hemoglobin however is an allosteric protein with four subunits, and exhibits cooperativity
high blood sugar causes low blood sugar causes
high blood sugar causes damage to retina, kidney, blood vessels and nerves low blood sugar can cause seizure or coma
post transcriptional processing of pre-mRNA
hnRNA= primary transcript 1. 5' 7-methylguanylate triphosphate cap is added ---- ribosome binds here and protects against nuclease 2. 3' poly A tail = protects from exonucleases 3. splicing by spliceosome (removal of introns and possiblly alternative splicing) (mnemonic: 5' to 3' ---- tail is lower)
Amides in alkaline conditions undergo
hydrolysis to form ammonia and the salt of the corresponding acid X-CNH2 + NaOH + H2O ---> X-COONa + NH3 **the amonia gas would then bubble out of the liquid solution. ammonia is a base and when the gas hits the moist litmus paper above the tet tube, it would dissolve in the water and turn the litmus paper blue
injection of insulin is accompanied by the risk of infection. what is the most likely explanation for not giving insulin orally
insulin is digested by proteases in the stomach and small intestines. insulin is a peptide hormone and the GI tract contains proteases like pepsin, trypsin and chymotrypsin that could digest insulin before the SI could absorb it insulin is not a fat and is not emulsified by bile insulin is not a carbohydrate and would not be digested by amylase insulin would be digested by proteases before the issue of apsorption comes up in the SI, ruling out choice D as well
transgenic mice
integrating a gene of interest into the germ line or embryonic stem cells of a developing mouse
the velocity of fluid flow for an ideal or incompressible fluid in a pipe is related to radius how
inversely proportional to the radius of the pipe squared continuity equation: A1V1 = A2V2 **The volume of lfuid which passes through a pipe in a given amt of time must be conserved at any point in the pipe, so as the cross sectional area of the pipe increases, the fluid must slow down
phosphatidylserine
is a phospholipid nutrient found in fish, green leafy vegetables, soybeans and rice, and is essential for the normal functioning of neuronal cell membranes and activates protein kinase C which has been shown to be involved in memory function.
terpene vs isoprene
isoprenes are important precursor for many famiilies of compounds such as terprenes and steroids isoprene = unsaturated hydrocarbon (C5H8) terpenes = an unsaturated hydrocarbon obtained from plants
if the body needs to increase the amount of oxygen that reaches a tissue
it can either increase how much oxygen the blood is carrying or it can increase how much blood is flowing to the tissue (inc cardiac output)
kinases transfer phoshpate group from ATP and are usually?? phosphorylases are usually??
kinases are usually inactivating phosphorylases removing phosphate groups are usually activating
solvent will move in what direction osmotic pressure
low osmotic pressure to high osmotic pressure
you can treat gases as ideal gases at
low pressures and high temperatures Ideal = vacation on the beach (high temperature, no pressure)
low self esteem relationship to locus of control for negative events
low self esteem is associated with internal locus of control for negative events **low self esteem is also associated with disparity between actual and ideal self (who i am and who i wish i were), and poor coping skills
lacteal flows to
lymph fluid to the thoracid duct
all muscles develop out of what germ layer
mesoderm
genetic testing for MCAD deficiency can be challenging because multiple, distant sites within the gene can be mutated to produce disease, while mutations at other sites within the gene are benign what does this suggest about the necessary enzyme structure
most inactive enzymes have modifications of the active site, whihc is part of the tertiary structure
muscarinic vs nicotinic
muscarinic = GPCR ----- nicotinic = ligand-gated ion channels ---
chromic acid is a common (ochem)
oxidizing agent
only the component of force acting in which direction can perform work
parallel to the displacement
tumor suppressor gene
protein that naturally suppresses proliferation when mutated can lead to excessive proliferation and cnacer
promotors and enhancers
sequences of DNA that regulate expression of genes
polystyrenes
several genes in a single transcription
rectum
site of solid waste storage gut bacteria are not found here
spliceosome
small nuclear RNA (snRNA) with PROTEINS (small nuclear ribonucleoproteins - snRNPs)
fatty acid salts are what we know as
soap - act as surfactants acting as a detergent or emulsifyer which allow oils to dissolve in aqueous solutions
penetrance
the likelihood that a person with a given genotype will express the expected phenotype ex. 100 people are homozygous for an allele that is implicated in cancer, but only 20 develop cancer
cardiac cells arise out of
the mesoderm!
equal volumes of H2 gas and O2 gas exist at the same temp. what MUST be true of these two samples
the molecules of H2 gas will have the same average kinetic energy as the molecules of O2 gas
the more stable something is, what is its gibbs free energy
the more stable it is the lower its gibbs free energy
valency
the number of chemical bonds formed ex. tetravalent - carbon, silicon divalent - ca, s
aminopeptidase and carboxypeptidase
these enzymes cleave a single amino acid from either side of the protein, and don't act in a preferential manner
IN linkage possible gametes are limited because
they cannot assort independnetly!!
PCC
will convert a primary alcohol into an aldehyde without further oxidation to carboxylic acid
does systemic circulation include brain
yes
prokaryotes generate 2 more atp per glucose through glycolysis, pdc, cac, and etc??
yes eukaryotes have to use 1 atp to shuttle NADH into the matrix from the cytosol whereas prokaryotes do not (2 NADH made from glycolysis)
start codon
aug = methionine
The average molecular weight of an amino acid is
110 Da
A tetramer of a 288-residue protein is expected to have a molecular weight of
288 aa * 110 Da/aa ~~ 29000 Da = 29 kDa per protein 29 kDa * 4 (because it is a tetramer) ~~ 120 kDa
Which of the following parameters affects the Tm of dsDNA 1. pH of solution 2. ionic strength of solution 3. length of DNA strands
1, 2, and 3. All parameters would effect the thermodynamic stability of the dsDNA.
types of oxygen utilization
1. aerobic metabolism - uses oxygen obligate aerobe = requires oxygen 2. anaerobes = do not require oxygen facultative anaerobe = will use oxygen if it is present but do not rely on it tolerant anaerobe = can grow in the presence of O2 but do not use O2 for metabolism obligate anaerobe = poisoned by oxygen
real fluid equations
1. change in pressure = flow X resistance 2. flow = (pir^4)/(8 X viscosity X length)
kinetic theory of gases holds 4 assumptions
1. random molecular motion 2. no intermolecular forces 3. neglibible molecular volume 4. perfectly elastic collisiosn
the ideal gas obeys the kinetic molecular theory of gases and has the following properties
1. random molecular motion 2. no intermolecular forces 3. no molecular volume 4. perfectly elastic collisions
What method separates proteins based on their charge 1. SDS-page 2. Isoelectric focusing 3. Ion-exchange chromatography 4. Affinity chromatography
2 and 3 only. SDS-page separates proteins based only on their mass. Affinity chromatography separates proteins based on their interactions with highly specific ligands. Isoelectric focusing separates proteins based on their isoelectric point (the pH at which the charge on the protein is neutral) and ion-exchange chromatography separates proteins based on their net charge.
voltmeter vs ammeter
An ammeter is a measuring device used to measure the electric current in a circuit. A voltmeter is connected in parallel with a device to measure its voltage, while an ammeter is connected in series with a device to measure its current.
61 - Nicke
Anytime you tag something and send it through = affinity
Sigmoidal
Cooperative processes
transport of glucose in some cells up its concentration gradient requires
Co transport of Na+ ions down a concentration gradient
based on the general theory of enzyme action, the overal rate of the reaction (at all substrate and enzyme concentrations) is proportional to the concentration of
ES complex
exonuclease
Exonuclease: this gives the enzyme a proofreading and repair activity i. DNA polymerase also has exonucleases activity which removes nucleotides
what affects acid strength....intramolecular factors or intermolecular factors
INTRAMOLECULRA FACTORS (such as number of resonance structures, atomic radius and polarity) Intermolecular factors (ex. hydrogen bonding) does not play a role in acid strength, as they do not influence the dissociation of the acidic hydrogen
Cytochrome c is found
In the membrane of the mitochondria. It is released into the cytosol when apoptosis is initiated.
Under normal physiological levels, increased activity of succinyl co a will result in
Increased ATP Increased succinate
threshold of hearing
Io = 1X10^-12 ==== 0 dB!!
nitrification
N2 is converted to NH3 which is then processed by nitrification to create NO3 which can be used done in soil
enzymes function over narror or wide pH range
NARROW pH RANGE!! significant changes would affect the structure, and therefore the function of the protein
does carbonic anhydrase favor the forward reaction or the reverse reaction
NEITHER!!! Carbonic anhydrase decreases the energy activation for BOTH H2CO3 synthesis and degradation EQUALLY!
cytosine guanine hydrogen bond
cytosine donates 1 H guanine donates 2 H
Lipoic acid is a cofactor for
Pyruvate dehydrogenase which catalyzes the conversion of pyruvate to acetyl co a
An enzyme is more effectively inhibited by uncompetitive inhibitors when
Substrate concentration AND inhibitor concentrations are increased Uncompetitive inhibitors can only bind to the E-S complex, so in order for inhibition to increase, substrate concentration must also increase. Increasing the amount of inhibitor will obviously be directly related to degree of inhibition
How does the mRNA strand correspond to the coding DNA strand
The nucleotide sequence of both the mRNA strand and the coding DNA strand are complementary to the template DNA strand. Meaning that the mRNA strand and the coding DNA strand are the same (with the replacement of uracil for thymine).
To control for the possibility of two enzymes autophosphorylating, the control lane in isoelectric gel should be...
The two kinase enzymes with ATP alone. There should be NO substrate. Autophosphorylation would not be possible without ATP. The substrate should not be included so that it is clear that any phosphorylation detected is due to autophosphorylation.
tidal volume
Tidal volume is the lung volume representing the normal volume of air displaced between normal inhalation and exhalation when extra effort is not applied
adenine thymine hydrogen bond
adenine donates 1 H thymine donates 1 H
cellulose
beta linked NO BRANCHING
what organs are insulin independent
brain red blood cells
terpenes
made from isoprene subunits - vitamin A : important for vision - precursors to steroids - produced mainly by plants and insects -monoterpenes have two isoprene subunit (10 carbons) -sesquitterpenes have three isoprene subunits (15 carbons) -diterpenes have four isoprene subunits (20 carbons) -triterpenes have six isoprene subunits (30 carbons)
osmolality
measure of the osmoles of solute per kilogram of solvent
mutarotation
mixture containing both anomers (epimers with different configurations around anomeric carbon) in their equilibrium concentrations
southern blot
molecular biology lab technique used to assess DNA expression
chitin
not produced by humans found in the cell walls of fungi and the exockeletons of arthropods
most of mitochondrial proteins are encoded by
nuclear genes
indicator dyes are best used when
only a rough knowledge of acid or base concentration is needed
insulin is what type of hormone
peptide hormone
enantiomers will share
physical properties such as density, boiling point and heat of combustion
hybridization
separated DNA strands which spontaneously associate with a complementary strand
dna pol always synthesizes from? reads from?
synthesizes from 5' to 3' reads DNA template strand from 3' to 5'
critical temperature
temperature above which you can no longer get a liquid no matter how much pressure you press on it
self-effacing bias
tendency to attribute success to external factors
an increase in acetylcholine uptake would decrease...
the effective amount of acetylcholine acting in the cell
the pI of an essential amino acid can be described by which of the following
the pH at which the amino acid has no net charge
reflexxes are controlled exclusively by
the spinal chord
bacteriophage
virus that infects and replicates within a bacterium
virus size compared to bacteria and eukaryotic proteins and cells
viruses are smallest and roughly the same size of some bacterial and eukaryotic PROTEINS bacteria CELLS are about 100 times LARGER than viruses eukaryotic CELLS are about 1000 times LARGER than a virus
primary function of colon (LI)
water absorption and electrolyte abosroption
(+) (d) (D) (L) (R) (S) designatiosn
(+) and (d) refer to dextrorotatory (-) and (l) refer to levorotatory (R) refers to onfiguration that rotates clockwise (S) refers to configuration that rotates counterclockwise (D or L assigned by imagining a resemblance between the ligands on chiral center and those in glyceraldehyde .... similar groups to glyceraldehyde becomes D.....if there is mroe than one chiral center the D or L distinguishment depends on the highest numbered chiral center.....for sugars D sugar is if OH is on the rihgt)
what will produce the greatest change in osmotic pressure
(osmotic pressure = iMRT) where i = van hoffs factor OSMOTIC PRESSURE IS A COLLIGATIVE PROPERTY that is dependent upon the number of particles present the answer that will affect osmotic pressure the most is the compound that will produce the greatest number of particles
deviation of real-gas behavior from ideal gas law (qualitative)
- when molecules are far apart (under conditions of low P, high T) they are ideal - when molecules are brought closer together (higher p, lower T) they experience intermolecular attraction -when molecules are brought so close together that they clash into one another, they experience steric repulsion
enzymes are regulated by four means
1. proteolytic cleavage (peptide bond cleavage activates the enzyme) -the enzymes are released as proenzymes or zymogens 2. reversible covalent modifications -kinase adds phosphate from atp to -OH (ser, thr, tyr) -phosphorylase adds a phosphate from Pi -phosphatase removes a phosphate 3. control proteins (protein subunits associate with enzymes to either activate or inhibit their activity ) - ex. calmodulin, G-proteins 4. allosteric interactions (binding of an activator or inhibitor at the allosteric site)
earthi si how old
4.5 billion years life itself is 3.5 billion years
Let a1 be the acceleration felt by a ball in trial 1. Let a2 be the acceleration felt by a ball in trial 3. How do a1 and a2 compare? A. a1 = a2 Correct Answer B. a1 = (1/2)a2 C. a1 = 2a2 Your Answer D. a1 = 0
A. The force felt by a charge is F = |q|E = ma, so a = |q|E / m. (The actual translational acceleration of the rolling balls is affected by their rotational inertia, but that affect is the same for each trial and so it does not affect the answer.) In this case, |q|, E, and m are the same for both a1 and a2, therefore a1 must equal a2 (making the correct choice A). Notice the magnitude and direction of the initial velocity does not matter in determining the acceleration; nor does the initial position. The direction of a when q is positive will be the opposite of the direction of a when q is negative, but if |q| is the same for both, then a will be the same for both.
When designing a variant for a residue that is phosphorylated, which amino acids should NOT be used
Anything that has a hydroxyl functional group in its side chain. Primarily, serine, threonine and tyrosine. Aspartate and glutamate also have the potential to be phosphorylated because of their -COOH functional groups
dynamic equilibrium vs static equilibrium
BOTH have no net force or torque, and therefore both have no acceleration Dynamic has constant velocity, while static equilibrium's velocity is a constant ZERO
which hydrogen halide has the highest BP
BP and MP primarily determedn by strength of intermolecular forces strong intermolecular forces result in high boiling and melting points only HF udnergoes h bonding, so it will have a hgiher BP than any of the other chioicses
how do blood flow rate (BFR) and blood pressure (BP) differ in pulmonary and systemic circulation
BP is greater in systemic and BFR is the same for both because pulmonary circulation is much shorter than systemic, resistance is also much less, analogous to the resistanc eformula (R= pL/A) . compound this with the fact that the right ventricle (which feeds the pulmonary circulation) generates less force than the left ventricle (which feeds the systemic circulation)) Since pressure = force/area, this means that pulmonary pressure is less than systemic Since pulmonary circulation and systemic circulation are connected in series, flow rate (analogous to current) must be equal
cerebroside
Cerebrosides is the common name for a group of glycosphingolipids called monoglycosylceramides which are important components in animal muscle and nerve cell membranes. They consist of a ceramide with a single sugar residue at the 1-hydroxyl moiety. The sugar residue can be either glucose or galactose; the two major types are therefore called glucocerebrosides and galactocerebrosides. Galactocerebrosides are typically found in neural tissue, while glucocerebrosides are found in other tissues.
commensalism
Commensalism is a relationship between two organisms where one receives a benefit or benefits from the other and the other is not affected by it. In other words, one is benefited and the other is neither benefited nor harmed.
ceramide
Composed of sphingosine and a fatty acid, _______ are a family of lipid molecules found in high concentrations within the cell membrane.
cell cycle
G1, S, G2, M interphase = Gap pahses plus s phase M phase = mitosis and cytokinesis Mitosis = PMAT
dna libraries vs genome libraries vs cDNA libraries
Genome libraries contain both coding and noncoding regions AND CANNOT BE USED TO MAKE RECOMBINANT PROTEINS OR USED FOR GENE THERAPY!! cDNA libraires contain smaller fragments of DNA and ONLY INCLUDE THE EXONS OF GENES EXPRESSED BY THE SAMPLE TISSUE! --- can be sued to make recombiant proteins for gene therapy
Which enzyme catalyzes the production of 6-phosphogluconolactone
Glucose 6 phoshpate dehydrogenase
What enzyme catalyzes the rate limiting step in the breakdown of glycogen
Glycogen phosphorylase
current equations
I = delta Q / delta t
Reverse transcription PCR
Reverse transcription polymerase chain reaction (RT-PCR), a variant of polymerase chain reaction (PCR), is a technique commonly used in molecular biology to detect RNA expression
Objects A and B are placed on the spring. A has mass 2X as large as oject B If the spring is depressed and released, propelling the objects into the air, object A will
Rise to the same height as object B "A simple technique for solving this and many other physics problems is to consider situations at their extremes. Here the examples are reasonably close in mass. WHat if object A were one million tims as massive as object B? Imagine that object A is a piano and object B is a dime. Now place them on a spring and propel the piano one inch into the air. Will the dime be propelled one million inches into the air at the same time? Of course not. Mass is not propotional to the height. Since all answers are given as such (proportional to height), only C can be the answer
gastrointestinal hormones secreted by what following meal?
SMALL INTESTINE!!! 1. secretin == stimulates sodium bicarbonate secretion by the pancreas -- released due to hydrocholirc acid in the duodenum 2. cholecystokinin (CKK) = causes gallbladder contraction and pancreatic enzyme secretion and decreases motility of the stomach allowing the duodenum to digest nutrients -food in the upper duodenum causes the release of this hormone 3. gastric inhibitory peptide = decreases the motor actiivty of the stomach - released in response to fat and protein digestates in the duodenum
vas deferens vs seminiferous tubules
Seminiferous tubules: produce sperm vas deferens = stores sperm, connects testes to urethra
Isoelectric focusing
Separates proteins based on isoelectric point To do this, a stable pH gradient must be established in the gel
sertoli vs leydig
Sertoli: stimulated by FSH, surround and nurture spermatocytes and spermatids · Leydig: release testosterone when stimulated by LH
A curve for the unfolding of a protein is
Sigmoidal It is a cooperative process
sphingosine
Sphingosine (2-amino-4-octadecene-1,3-diol) is an 18-carbon amino alcohol with an unsaturated hydrocarbon chain, which forms a primary part of sphingolipids, a class of cell membrane lipids that include sphingomyelin, an important phospholipid.
ionic and covalent bonds form between
TIRCK QUESTION! inTRAmolecular bonds FORM WITHIN A MOLECULE (*inTERmolecular bonds form BETWEEN molecules)
tight junction vs desmosomes vs gap junction
Tight junction: create tight seal between cells preventing fluids from passing through a membrane b. Desmosomes: strong point welds holding cells together but without a water tight seal c. Gap Junction: tunnels between cells that allow solutes to flow through between cells
totipotency
Totipotency is the ability of a single cell to divide and produce all of the differentiated cells in an organism. Spores and zygotes are examples of totipotent cells. In the spectrum of cell potency, totipotency represents the cell with the greatest differentiation potential.
What type of inhibitor does not alter the Km/Vmax ratio?
Uncompetitive inhibitors ---> because they decrease both Km and Vmax ***** Competitive --- increases Km, no effect on vmax Mixed ------ can either increase or decrease Km, decreases vmax Noncompetitive (subset of mixed) ---- no effect on Km, decreases vmax
hypochlorous acid is added to a swimming pool until the concentration reaches .1 M and the concentration of the hpyochlorite ion reaches .01 M. what is the pH of the pool
Use henderson hasselbalch ph = pka + log (A-/HA) pH = 7.5 + log (.01/.1) = 7.5 + (-1) = 6.5
kcat
Vmax / [E]
pluripotent
a cell capable of giving rise to several different cell types this lasts a few phases longer than totipotency
inhalation facilitates venous flow towards the right atrium by expanding the thoracic cavity and iducing
a decrease in cavity pressure "this question is really just asking how negative pressure breathing works - in the same way that air will rush into the lungs as a result of decreased pressure, so too will venous blood rush into the cavit with less pressure than the area that came before it
mitochondrial proteins encoded by own single circular DNA use what system of transcription and translation
a different system of transcritpino and translation thatn nuclear gnees
cecum
a pouch connected to the junction of the small and large intestines. Normal gut bacteria are found in the cecum!
why is MCAD deficiency more likely to appear earlier (as soon as a few days after birth) in bresatfed infants? initially, breastfed infants receive
a smaller number of carbohydrate calories than bottle fed infnants KAP RT2 Q25 A larger supply of medium chain fatty acids would not exacerbate symptoms bc MCAD has to do with beta oxidation, not storage of the fatty acids
pore / porins
a tube that is not selective for a particular molecule JUST SIZE
primary vs secondary active transport
active transport = movement against the gradient (requires energy input AND a protein) primary = coupled to ATP hydrolysis secondary = not coupled directly to ATP hydrolysis but to ion gradient
chromatography separtes based on
affinity for the stationary phase; the lower the affinity of the compound for the stationary phase, the faster it will be eluted through the column this means that the compound that has the lowest affinity for the stationary phase will be the first compound to reach the detector which is located at the end of the column
metaphase mitosis
all choromosomes line up at the center of the cell along the metaphase plate each sister chromatid is attached to spindle fibers from the opposite end of the cell, pulling them in opposite directions
secretory pathway
all proteins begin translation in the cytoplasm but those that complete translation on RER are directed to ORGANELLES, MEMBRANES, or OUTSIDE THE CELL!!
gpcr are made of what secondary structure
alpha helixes
starch
alpha linked -amylopectin has branching from carbon 6 -amylose has NO BRANCHING!!
replication of bacteriophage vs animal virus
bacteriophage: lytic cycle or lysogenic cycle animal virus: productive stage or lysogenic stage productive stage is similar to the lytic cycle except that the productive stage does not kill the cell. the virus exists the host by budding through the host membrane and coating themselves with the membrane Most animal viruses have an envelope
researchers constructed a lens with the same optical power as the change in power over 5 years in undercorrected hyperopia patients. what is the focal length and type of this lens? (EK physics 97)
based on figure 1, the change in power each year in undercorrected subjects is -0.43 dipopters. so, over 5 years, there is a total change of -2.15 dipopters. the focal length is the inverse of the power, so the focal length is 1/-2.15 = -0.47 m = -47 cm the negative indicates that this is a diverging lens
volumetric flow rate of blood in circulatory system
bc the circulatory system exists in a closed state, the volumetric flow rate of blood must be constant throughout
beta vs alpha
beta linkage is when the ch2oh and the anomeric oh are cis alpha is when they are trans BETA = ITS BETTER TO BE THE SAME (cis) ALPHA = ITS BETTER TO BE OPPOSITE (trans)
how do beta and gamma readiation differ in a magnetic or electric field
beta particles have a neg charge and will be deflected because they are charged. gamma rays are high energy photons lacking any charge. they will not be deflected because they are not charged
the pancreas secretes what to aid in digestion
bicarbonate!! acts to neutralize the acidity of the stomach
irreversible inhibitors
bind covalently
glucosidase
breaks apart glucoside
D vs L
carbohydrates - D/L = absolute configuration = assigned based on the chriality of the carbon atom furthest from the carbonyl group D is for R L is for S
at extremely high pressures and low temperatures, gases
cease to be gases at all - they condense into liquids
dglucose and d fructose are most precisely characterized as
constitutional isomers the first question to ask when comparing two structures is "do they have the same connectivity"
triterpenes
contain 6 isoprene subunits - can be converted into steroids and cholesterol
what is the delta H for a reaction
delta h = heat of formation (products) - heat of fomration (reactants)
denatured DNA relationship with UV light absorption
denatured DNA absorbs MORE UV light!
aldopentose
five carbon sugar with an aldehyde group ketopentose = five carbon sugar with a ketone group
the frequency of a wave traveling through a medium increasses with
increases with increasing tension and decreases with increasing linear msas or thickness (density) (**think of a guitar string --- thicker strings have lower tones than thinner strings &&&& tightening a string (increasing tension) increases the frequency or pitch)
microRNAs most likely
influence gene expression small, non-coding class of RNA that likely plays a role in gene regulation
as atmoshperic pressure increases, what happens to the vapor pressure
it remians the shame
bacteria energy source for growth
light or oxidation of organic or inorganic matter phototrophs: use light as their energy source chemotrophs: use oxidation of organic or inorganic matter
5 kingdoms
monera protist fungi plantae animalia
signal sequence
n terminus translated AA sequences that direct ribosomes to RER signal recognition particle = protein that binds signal sequences and brings ribosome to RER and protein is translated into the RER. signal sequence is THEN cleaved
telophase mitosis
nuclear membrane reforms around chromosomes chromosomes decondense cytokinesis is complete
obligate anaerobe vs facultative anaerobe
obligate = only anaerobic facultative = aerobic if oxygen is present, anaerobic if not
the atria are the first to contract and they do so because
of action potentials generated by the SA node
oncogene vs protooncogene
oncogene results from turning ON of protooncogene the protooncogene encourages transcripiton or translation. when the oncogene is activated from a mutation of some other mechanism, it can lead to excessive proliferation (cancerous)
operon
operator promoter gene
diastereomers
optical isomers that are identical at one or more chiral centers and different at one or more chiral centers
organic acid
organic compound with acidic properties most common orgainic acid is carboxylic acids
fibrin
protein involved in the clotting of blood it is activated from fibrinogen (zymogen) by thrombin
litmus paper color
red - acid blue - base
glucoside
something attached to glucose
which organ is most reliant on glucose as its source of energy
the brain because it uses large amounts of energy and relies primarily on glucose for energy
equilibrium expression vs rate law
the concentrations of chemicals are raised to the power of their coefficient when writing an equlibrium expression, but THIS IS NOT THE CASE WHEN WRITING A RATE LAW For a rate law: the exponents above the concentrations of the chemicals must either be 1. gjiven as coefficient from RDS!! or 2. experimentally determined
the half-egg with a nucleus has
the same number of chromosomes as the whole egg and half the number of of chromosomes as an autosomal cll
(EK 124 test 1) .. to produce the covalently modified taxol (addiition of monosaccharide), researchers took advantage of which of the following enzymatic properties of alpha-glucosidase??
this eznyme breaks down sugar by removing a monosaccharide. in this case in the experiment, the researchers are using this enzyme to add a sugar. in other words, they are running a "reverse" reaction. THEY ARE TAKING ADVANTAGE OF that enzymes catalyze both forward and reverse reactions
when placed in an electric field, which of the following compounds will migrate toward the cathode
this question deals with the amphoteric properties of amino acids in order for a molecule to migrate to the cathode, its overall charge must be positive
termination of translation
when a stop codon reaches the A site, release factor binds to A site allowing the polypeptide to be freed from the tRNA and the ribosome breaks apart
polygenic
when a trait is influenced by many different genes (ex. height)
transduction
when a virus activates itself and excises itself from the host genome, and takes a small part of host genome with it and brings the fragment of the host DNA to its new host
secretion of erythropoietin
will increase the number of erythrocytes in the blood and thus increase the oxygen carrying capacity of the blod
color blindness is a
x linked trait
can anaerobic bacterria have ETC
yes SOME can and can use S as final electron acceptor
do cardiac cells contain mitochondria
yes cardiomyocytes contain large amounts of mitochondria
do white blood cells contain organelles?
yes they contain the same organelles as eukaryotic cells
how does z eff change down a group
z effective increases going up and to the right in the PT
electrons in the 1s subshell of which of the following elements experience the greatest effective nuclear charge h na cl o
zeff increases from left to right across the periodic table because of the increase in positive charge in the nucleus. because the question asks about 1s electrons, shielding effects can be ignored making the number of protons the most important factor
important temperatures
-273 C = absolute zero 0C = freezing point of water 20 C = room temp 37C = body temp 100 c = boiling point of water
two mechanisms behind speciation
1. allopatric isolation = diverging of species due to geographic isolation 2. sympatric isolation = when one species gives rise to another species in the same geographical area
post translational modifications
1. amino acid sequence determines the folding conformation, folding is assisted by proteins called chaperones 2. sugars or phosphate groups may be added - phosphorylation: addition of phosphates by protein kinases to activate or deactivate proteins -carboxylation: addition of carboxylic acid groups(usually to serve as calcium binding sites) -glycosylation: addition of oligosaccharides as proteins pass through the ER and golgi apparatus to determine cellular destination -prenylation: addition of lipid groups to certain membrane-bound enzymes 3. polypeptide may be cleaved in one or multiple places 4. separate polypeptides may join to form quaternary structure
mitosis prophase
1. chromosomes (consisting of two sister chromatids) condense and become visible 2. Nuclear envelope breaks down 3. spindle and kinetochore fibers appear (kinetochore fibser are attached to centromere at this point)
genetic exchange between bacteria
1. conjugation = exchange of genetic material by bridge between cells (one cell copies DNA and this ccopy is tranferred through the bridge to the other cell) -requires one bacterium to have a plasmid with the gene that codes for the sex pilus (F plasmid) -F plasmid contains the fertility factor -> encodes several genes including formation of sex pilus -F factor plasmid is replicated and transfered to F- (female) cell which then becomes F+ (male) 2. Transformation = bacteria take up DNA from external environments 3. Transduction = lysogenic viruses take up DNA from host and spread it to other cells when infected 4. HFR cell ==> cell that incorporates F plasmid into genome
how many stereoisomers of X exist
1. count number of chiral centers (carbons that are sp3 hybridized and have 4 different groups attached) 2. each chiral center can have the R or S configuration, so 2^n = number of stereoisomers
modes of natural selection
1. directional = if NS removes one extreme 2. divergent = remove the mean 3. stabilizing = remove the extremes
ex of nondisjunctino
1. downsyndrome (trisomy 21) 2. turner syndrom (monosomy X = external female appearnace but ender developed ovaries and sterility)
Fungi important things to kknow
1. eukaryotes 2. heterotrohps 3. cell walls are made from chitin 4. yeast are single celled fungi
lipid transport
1. free fatty acids bind to albumin 2. triglycerides -chylomicrons transport dietary triglycerides and cholesterol from the small intestine to tissues -VLDL transports triacylglycerol from the liver to the tissues 3. cholesterol -LDL delivers cholesterol into the cells -HDL picks up cholesterol accumulating in blood vessels and delivers cholesterol to liver and steroidogenic tissues!
hardy weinberg formulas
1. p + q = 1 2. p^2 + 2pq + q^2 = 1
6 types of viral genomes
1. plus stranded RNA: +RNA is mRNA and can be translated directly. 2. minus stranded RNA: -RNA is complementary to mRNA and must be transcribed before being translated. So it must encode and carry RNA dependent RNA polymerase so that it can be transcribed first to +RNA 3. Retroviruses: must encodee reverse transcriptase enzyme in order to create DNA from its RNA. ssRNA strand must first be reverse transcribed to a double stranded DNA. and then can incorporate itself into host genome -HIV 4. dsDNA: encodes enzymes for dNTP synthesis and DNA replication. cannot use host dNTPs and enzymes!!! LARGE GENOMES 5. Viroid: small rings of naked RNA without capsids. VIROIDS ONLY INFECT PLANTS 6. Prions: protein viruses that can reproduce themselves without DNA or RNA
most important for meiosis
1. production of haploid cells form diploid 2. recombination occurs between homologous chromosomes during prophase 3. anaphase 1: homologous chromosomes separate and sister chromatids remain together. At this point the cells are considered diploids 4. anaphase 2: separates sister chromatids to form HAPLOIDS!!
four colligative properties
1. vapor pressure lowering (Raoult's law) Vapor pressure = (vapor pressure of pure solvent alone) X (mole fraction of solvent) X (van't hoff factor) * when calculating xsolute, make sure to take into account vant hoffs factor --- ex. 1 mole of NaCl is equal to 2 moles of pariticles so xsolute would equal 2 2. boiling point elevation --- increase in boiling point = kb X molality X van't hoff factor 3. freezing point depression decrease in freezing point = -kf X molality X van't hoff factor 4. osmotic pressure osmotic pressure = MRT X van't hoff factor
starting with the translaiton initiation codon, the following sequence encodes a polypeptide of how many AAs? 5'- CUGCCAAUGUGCUAAUCGCGGGGG-3'
2 start codon = AUG stop codons = UAA, UAG, UGA
prostaglandins
20 carbon unsaturated molecules derived from fatty acids and may contain five rings - have both paracrine and autocrine activity through cAMP signaling - effect smooth muscles, influence sleep and elevate body temp - production inhibited by NSAIDS which inhibit the enzyme COX 9cycloxygenease)
How much ATP for translation?
50 AA protein ---> 199 ATP (#AA X 4 - 1) 4 components: A. 2 ATP / AA to attach AA to tRNA (100 ATP) B. 1 ATP to form initiation complex (1 ATP) C. 1 ATP / tRNA binding (49 ATP) D. 1 ATP / translocation (49 ATP)
Planck's constant
6.6 × 10-34 m2 kg / s
ethanol boiling point
78 C
two forms of gas constant
8.314 J/Kmol .082 L atm / K mol
fat soluble vitamins
A = carotene - important in vision (retinal), growth, and immune function D = formed by a UV reaction in the skin. converted to calcitriol which increases calcium and phsophate uptake in the intestine and increases bone production E = aromatic ring with long isoprenoid chain. act as antioxidants by reacting with free radicals and preventing oxidative damage which cause cancer and aging K = important for prothrombin activity , an important clotting factor in the blood
if pH of blood were to increase to 7.6, what would be the likely outcome... an increase or decrease in the rate of CO2 exhalation
A DECREASE IN THE RATE OF CO2 EXHALATIOn *in order to bring ph of blood back to normal value of 7.4, it must become more acidic ---- it becomes more acidic by increasing the concentration of H+. (the H+ concentration will increase if the concentration of co2 increases)
Substituting residues in a peptide with which AAs will most likely result in a peptide with increased pI.
A basic residue such as lysine or arginine will increase the pI An acidic residue such as glutamate or aspartate will decrease the pI Neutral AAs will not contribute to the pI *** pI is the pH at which a molecule carries no net charge pI = (pKa + pKa) / 2
Concentration cell
A concentration cell is a limited form of a galvanic cell that has two equivalent half-cells of the same composition differing only in concentrations. One can calculate the potential developed by such a cell using the Nernst Equation.
The reaction catalyzed by a kinase can be reversed by what type of enzyme
A phosphatase
benedicts reagent vs tollens reagent
ALDOSES AND HEMIACETALS ARE REDUCING SUGARS AND THEREFORE CAN BE OXIDIZED benedicts reagent = tests for reducing sugars.all hemiacetals, aldehydes and ketones give a positive result in benedict's test. acetals give a negative result because they can't open into straight chain carbonyl form --Cu2+ oxidizes C-1 aldoses --solution goes from blue to red Tollens = Ag+ oxidizes C-1 of aldoses resulting in a silver mirror. Tollens tests for aldose, checks for hemiacetals
a mountain climber living at sea level ascends to a very high altitude during the course of a day long climb. by the end of the day, all of the following acclimatizations will occur EXCEPT decreased heart rate inhaling more air than normal increased tidal volume increased secretion of erythropoietin
Answer: decreased heart rate.....a decrease in heart rate would decrease the perfusion of tissues with blood, thereby decreasing oxygen delivery. this would not happen to acclimatize the climber's body to the increased altitude (and lower partial pressure of oxygen)
Benedicts Reagent
Benedict's reagent is a chemical reagent commonly used to detect the presence of reducing sugars Benedict's reagent reacts with reducing sugars like glucose that contain hemiacetals to form a red precipitate, but not with non-reducing sugars that contain acetals, such as glycogen.
Using Dalton's law, which of the following is the correct equation to determine the partial pressure of a component, Py, based on the concentration in parts per million, Cy? A. Py = (PtotalCy)(106) B. Py = (Ptotal / Cy)(106) Your Answer C. Py = 106 / (PtotalCy) D. Py = (PtotalCy) / 106 Correct Answer
D. Dalton's law states that the sum of the partial pressures in a mixture of gases is equal to the total pressure of the mixture. Conversely, the partial pressure of a gas in a mixture is equal to the mole fraction of that gas multiplied by the total pressure of the gas, or Py = XyPtotal. Since Ptotal is in the numerator, choice C can be eliminated. To convert parts per million to mole fraction: Therefore, Xy = Cy / 106, making choice D the correct answer.
recombinant dna (dna tech)
DNA from different sources that has been artificially combined -plasmid: circular self-replicating DNA that is often used as vectors - DNA cloning introduces a fragment of DNA into a vector plasmid ---A. === DNA libraries are large collections of known DNA sequences ----B ==== Genome libraries are large fragments of DNA, including both coding and noncoding regions
hybridization
DNA-DNA hybridization generally refers to a molecular biology technique that measures the degree of genetic similarity between pools of DNA sequences. It is usually used to determine the genetic distance between two organisms.
DONV is a competitive inhibitor with an extrememly high affinity for the active sites of its target enzymes. DONV is most likely which of the following types of molecules a. phospholipid b. allostericially inactivating immunoblobulin c. synthetic nucleoside d. non=standard amino acid
DONV is a competitive inhibitor of L-asparginase with a high affinity for its activie site. in order to bind tso tightly with thte active site of a n enzyme, the inhibitro must have an extremely similar structure to the natural ligand. based on its name, l-asparaginase is expected to act on L-asparagine, one of the twenty amino acids used by humans. based on this information, DONV is most likely also an AA, making choice D the most correct answer. t there is no reason to believe that a pohoshpolipid or a nucleoside would ahve higher binding affinity fro an enzyme that recognizes AA than an AA, meaning choices A and C can be eliminated. Although choice B describes a mechanism by which an enyzme like L-aspariginase could be inhibited, the passage describes DONV as a competitive inhibitor, not an allosteric activator
do acid anhydrides easily form an aqueous solution
DUE to theier HIGH REACTIVITY, upon ocming into contact with water, they reform the original carboxylic acid AND THEREFORE DOES NOT EASILY FORM AN AQUEOUS SOLUTION
Elimination of pi-stacking interactions (for instance the removal of an aromatic AA such as tryptophan)
Decreases stability of the E-S complex. This will likely raise the Km
ethnographic methods
Ethnography is an extremely broad area with a great variety of practitioners and methods. However, the most common ethnographic approach is participant observation as a part of field research. The ethnographer becomes immersed in the culture as an active participant and records extensive field notes.
(EK physics 78) how much work is doen to move a point charge (q) a distance of x, at an angle of 30 degrees to the lines of force of an electric field (E)
F= qEx cos(30) work is equal to the electric potential energy, qEd, where d, idsplacement, is parallel to the lines of force. any ;movement perpendicular to the lines of force (equipotential lines) represents NO WORK!!! therefore, only movement in the direction of the lines of force are contributory to work!
Which AA of a substrate is most likely to interact with a given residue of a given enzyme
First, determine the WT amino acid. The substrate AA will be complementary to the enzyme AA. For instance, if the given residue is aspartate, a likely substrate AA could be lysine or arginine. *** This question could also be getting at sterics. If for example, a variant's side chain is substantially different in size (and there is a resulting change in Km) it could be that the AA that will best interact with the residue is one of a complementary size.
(EK physics 110) which of the following is true when comparing ultraviolet rays and x-rays a. uvrays have a higher amp b. xrays have a higher amp c. uv rays bend more when passing from air to glass d. xrays bend more when passing from air to glass
HIGHER FFREQUENCY UNDERGOES GREATER DIFFRACTION!!!! amplitude of a ight wave is based on quantity, not quality. it is not entirely dependent on the type of light, as in UV versus x=ray, but rather on the quantity and energy carried by the light. simply knowing the type of light gives nothing away regarding amplitude, so choices A and B are unlikely. different types of light refract differently at the same interface, so choices c and d are both possible. higher frequencies of light are refracted more because objects are more likely to absorb higher frequency light. this causes those frequencies of light to travel more slowsly and be refracted more. to complete this question, it is important to know the electromagnetic spectrum and how different types of light bend at the same interface. uv rays have lower frequencies thatn x=rays, so they bend less at an air glass interface. choice c is can be eliminated. choice d is the best answer because x rays have higher frequency and undergo greater refraction
What AAs are likely present at the dimerization inteface?
Hydrophobic AAs. Polar and charged AAs are likely to interact with water and are unlikely to be involved in protein-protein stabilization.
BrdU is often used as a measure of cellular replication levels within a tissue. which of the following tissue types would not be appropriate for a BrdU analysis of replication
In order to accurately measure DNA replication ONLY, it is important to eleiminate other causes of nucleotide (and BrdU) incorporation into chromosomes. One such cause is DNA damage, which can activate cellular machinery to incorporate new nucleotides in the place of old, damaged ones. FOr this reason, using BrdU labeling on tissue that has recently been exposed to radiation could lead to an overestimation of the level of cellular replication, and choice B is thus correct Benighn tumor cells, epithelial tissue, and stem cells should all be undergoing replication without high levels of DNA damage between replicatative cycles, meaning BrdU should be accurate i nthese tissues
an immunodeficiency reduces the binding specificity of antibodies in the human body. which of the following would be a symptom of this disease
Increased risk of autoimmunity. If the antibodies and immune response become less specifiic, then the likelihood of a response to self, or autoimmunity, increases dramatically.
In many harbors, old automobile tires are hung along the sides of wooden docks to cushen them from the impact. The tires deform in accordance with Hooke's law. As a boat is brought to a stop by gently colliding with the tires, the rate of deceleration of the boat
Increases until the boat stops. F = -k(deltaX) As the impact time increases, the displacement of the tires increases. As the displacement increases, the Force increases. As force increases, acceleration increases. As the acceleration in the opposite direction (relative to compression) increases, the deceleration increases (same thing, jsut different terms)
The highest measured current at a given voltage during the experiment would most likely be produced by which mass ratio of these salts
Increasing the molarity of an ionic solution increases its ability to conduct electricity NaCl has a lower molecular weight than KCl. For any equal mass of each salt, NaCl will always produce more moles. So, the ratio that has more NaCl will be the best
how will an amphipathic species affect the intermolecular forces between water molecules
It will decrease the intermoelceulat forces between water molecules
celsius and kelvin relationship
K = c+ 273
Max KE of an electron
K(max) = hf - work function
do carboxylic acid derivatives undergo nucleophilic addition reactions like aldol condensation
NO they undergo something more similar to nucleophilic substitution
effect on blood pressure....if NO was inroduced in the arteries around the circulatory system
NO causes relaxation of smooth muscle, and hence would cause expansion of arteries as arteries expand, blood travels out to the extremities. this results in heat loss through areas such as the hands and feet. the increase in arterial volume results in lower blood pressure.
do electrochemical cells have salt bridges
NO!!! electrochemical cells current flows is maintained by the battery, NOT THE SALT BRIDGE
does current flow through a salt bridge
NO!!! in a galvanic cell, current flows through the electrodes and a metallic wire the salt bridge prevents charge buildup which allows current to keep flowing (counteracts the buildup of charge created by current flow)
Newton's third law states that for every action there exists an equal and opposite reaction. What is the force that acts in reaction to the force of Earth's gravity on an object on its surface
Newton's third law refers to the same TYPE OF FORCE acting BETWEEN TWO OBJECTS In this case the earth exerts a force of gravity on an object and the object exerts an equal and opposite force on the Earth. Answer: The force of gravity that the object exerts on the Earth
in the experiment in passage 3 of EK1 (diffusion of CO2 out of room) which of the following gasses would give a different results He Xe SF6 N2
Nitrogen would behave differently bc of the already high quantitites of nitrogen in the air nitrogen contributes the largest proportion of the gases in the aire, upwards of 75% releasing a small amt of N2 would not detectably inc the partial pressure of nitrogen and there would be less of a concentration gradient for nitrogen to diffuse down
two copper leads are placed in a beaker containing distilled water, and avoltage is apllied across them. what level of current travels through the water
No current flows because distilled water is a poor conductor of electricity **distilled water is pure H20 which is a poor conductor of electricity. the dissolved ions necessary for carrying current by moving along their voltage gradients are ABSENT in distilled water **for everyday normal water (non-distilled) the current is HIGH because water has very low resistance to electric current & because it contains significant amounts of dissolved ions
What happens to covalently linked subunits in SDS-page
Nothing! They are not broken apart Furthermore, disulfide bonds will only be broken apart under reducing conditions. Other covalent bonds will remain intact.
What mechanism can restrict the expression of a given gene to a particular cell type?
Nuclear factors for the expression of the given gene. The gene itself, its promotor and its enhancers will be present in all cells. Nuclear factors are the only variable that will differ between cells, and can therefore confer both temporal and spatial regulation of the cells' target genes.
Signal sequence domain
Protein domains required for proteins that are directed toward secretory pathways
Resistance
R = pL/A
if the voltage across a capacitor is doubled, the net force on the dipole will
REMAIN THE SAME the net force on the dipole is zero. capacitors create a constant electric field across their plates, so the force exerted on the positive end of the dipole will be equal and opposite to the force exerted on the negative end of the dipole therefore, the net force on the dipole is zero, and when doubled, remains zero
amino acid loading of tRNA
REQUIRES 2 ATP aminoacyl-tRNA synthase enzyme: attach the appropriate AA to each tRNA molecule -enzyme recognizes both the tRNA and the amino acid based upon 3d structure -aminoacyl-tRNA synthase specific to each tRNA, ensures specific amino acid delivery
what is a likely reason to use reverse transcribe RNA in cel samples?
RNA found in the cell represents genes that the cell is actively transcribing, providing a representation of which genes the cells are expressing and the quantity in which they were being expressed
Which enzyme was LEAST likely used in the synthesis of cDNA? DNA polymerase? RNA polymerase Reverse transcriptase DNA ligase
RNA polymerase is not used during cDNA cloning. DNA pol is used to amplify the DNA. Reverse transcriptase is used in reverse transcription of RNA to cDNA. DNA ligase is used ligation of the cDNA to DNA vector
What technique cannot be used to analyze gene expression? Western blotting Northern blotting Southern blotting Reverse Transcription PCR
Southern blotting. Southern blotting is used to detect a particular DNA sequence in a strand of DNA.
transduction vs conjugation vs transformation
TRANSFORMATION = occurs when a bacterium acquires a piece of genetic material from the environment and integrates that piece of genetic material into the host cell genome. this is a common method by which antibiotic resistance can be acquired CONJUGATION = bacterial form of mating (sexual reproduction) TRANSDUCTION = occurs when a bacteriophage acquires genetic information from a host cell.
all of the following must increase with temperature except a. rate of an exothermic rxn b. givvs free energy of a spontaneous reaction c. entropy of a substance d. avg speed of molecules in a gas
accd to arrhenius equation, the rate of the reaction must increase as temperatrue increases, regardless of whether the reaction is exothermic or endothermic, so choice A can be eliminated. Entropy also increases with temp, as molecules within th esubstance have greater KE and the system moves toward a greater state of disorder, so C can be eliminateed The avg speed of molecules in a gas is directly proportional to the temp of the gas, as stated in the kinetic theory of gases, so choice D can be eliinated B is not always true, because as temp increases, gibbs free energy can decreaase
effect of acetylation and methylation for transcription regulation
acetylation of lysine residues on histone proteins loosens the chromatin which ACTIVATES transcription methylation of adenosine and cytosine nucleotides DECREASES/SILENCES gene expression
NADPH does what
acts as electron donor in biochemical reactions for fatty acids and cholesterol specifically production of bleach for immune functions protects against free radicals by producing glutathione (NADH feeds the ETC)
peliotropic
alteration of a gene alters many different, unrelated aspects of the organisms total phenotype (ex. mutation of a gene alters development oft he heart, bone and inner ears)
amylopectin vs amylose
amylopectin ahs branching while amylose does not
feedback inhibition
an end product shuts off an enzyme early in the pathway USUALLY THE ENZME THAT CATALYZES THE IRREVERSIBLE STEP
bacterial production of MSG from sugar molasses is
anaerobic and occurs after glycolysis
autosome
any chromosome that is not a sex chromosome
terpene
any of a large group of volatile unsaturated hydrocarbons found in the essential oils of plants, especially conifers and citrus trees. They are based on a cyclic molecule having the formula C10H16.
basic enzyme kinetics - affect of inc substrate ? inc enzyme?
as the relative concentration of substrate increases, the rate of the reaction also increases, but to a lesser and lesser degree until a max rate (vmax) has been achieved the vmax is proportional to active enzyme concentration!!
northern blot
assesses RNA expression
e coli
bacteria that produces b12, k and thiamin and riboflavin LOCATED IN LARGE INTESTINE
why does ethanol precipitate DNA
bc the added sodium acetate introduces sodium cations that interact with DNA's negatively charged phosphate backbone, leaving the DNA too polar to remain soluble in the substantially less polar ethanol solution Ethanol is chosen bc it is miscible with water and will not form two phases. Its addition serves to reduce the polarity of the solution, thereby precipitating the extremely polar DNA **THE BEST CHOICE IS A MOLECULE THAT IS MISCIBLE WIth WAter BUt ALso non-POLAR ENOUGH TO PRECIPITATE DNA
proline role in secondary structure
because of its rigid cycle structure, proline produces kinks and is therefore rarely present within the alpha helixes or beta sheets but is often present in the beginning of where they turn
menkes disease is an x linked, recessive disorder that affects distribution of copper. in a certain family, the father is hemizygous for Menkes disease and the mother is heterozygous for the disease. what percentage of their male offspring would be expected to have the disease
because the disease is x linked recessive, we know that both the mother and the father have exaclty one affected x hromosomoe 50% of the male offspring will have it
compare benzen's boiling point to waters
benze has a boilng point of 80 C while water has 100C benzene is exteremly NON polar and will only be capable of making very weak intermolecular forces like London dispersoin forces. so it will more readily enter the gaseous phase (equivalent to saying it has a lower BP)
type 1 diabetes typically occurs as a result of autoimmune destruction of
beta cells in the islet of langerhans of the pancreas (destruction of the cells that produce insulin)
fMRI vs MRI vs PET
both fMRI and PET are used to study brain functioning - PET depends on how much metabolic activity is going on in that region (this is not necessarily correlated to activity in the brain) --- fMRI generally shows blood flow into a region and more specifically relates to activities of neuronal actions there. fMRI first requires MRI MRI = imaging technique often used to show brain structures (uses magnetic fields and radio waves to form IMAGES - doesn't show activity like fMRI or PET) CAT = computed axial tomography - detailed structural images of body/brain - basically sophisticated 3D x-ray machine Xray - basic 2D picture of the inside of the body Xray is more dangerous compared to MRI but you cannot get MRI if you have metal in your body (even some tattos are forbidden) ** MRI is recommended for children and individuals that require multiple scans ** CT scans are cheaper and more readily available than MRI ** MRI takes much longer than CT (around 45 min vs a few min) **X ray is most basic (broken bone) where MRI or CT is used when more detail is needed
acidosis due to accumulation of ketone bodies in blood. what compensatory chages would take place in the body
breaathing rate would increase and total blood CO2/HCO3- concentration would decrease
acetylcholinesterase
breaks down acetylcholine will decrease acetylcholine levels and decrease the activation of postsynaptic receptors
maltase
breaks down the disaccharide maltose
for every increase in 10db, the intensity of power increases by
by a FACTOR of 10 (10X)
assuming classical mendelian inheritance, how can one differentiate between a homozygous dominant individual and one who is heterozygous for the dominant trait
by crossing each individual with a known homozygous recessive or a known heterozygote and examining the offspring **to differentiate between a homozygous dominant and a heterozygous dominant for a trait that exhibits classic dominant/recessive Mendelian inheritance, one must perform a cross that results in offspring that reveal the unknown parental genotype; this is known as a test cross
carrier proteins
carrier proteins = do not form a tunnel through membranes ---> BIND the molecules that need to be transported and then undergo a CONFORMATIONAL CHANGE to move the molecule to the other side of the membrane TYPES = uniport, symport, antiport
re-colonizing bacteria are most likely harbored by the
cecum
polysaccharides
cellulose starch glycogen
humanistic perspective
centered on the use of free will and how to best apply it
GA synthesizes
certian macromolecules such as polysaccharides to be secreted
codominant vs incompletely dominant
codominance occurs when both alleles are simultaneously expressed, and the phenotype has both traits fully present. Ex. blood type incomplete domiannce is when each allele is expressed, but the phenotype is an average of the two possible phenotypes (ex. a red flower and a white flower ---> pink flower)
osmotic pressure
colligative property the pressure applied to a pure solvent to prevent osmosis. is related to the concentration of the solution somotic pressure = iMRT
combined gas law vs ideal gas law
combined: P1V1/T1 = P1V2/T2 ideal: PV = nRT *combined comes from ideal. nR is constant so can cancel out
fluidity of membrane depends on
composition of fatty acids and cholesterol FA: - the more saturated the fatty acid, the less fluid -----saturated lack double bonds and are straight with strong van der wall forces -------unsaturated have a kinked structure and pack more loosely Cholesterol: - buffers membrane fluidity, keeping membrane more fluid at high and low temperatures ***makes less fluid at high temps and more fluid at low temps
behavioral modeling
consciously or unconsciously imitating the behavior of someone else who is modeling the behavior being imitated
pefectly elastic collisions mean
conservation of total kinetic energy
(EK physics 105) the index of refraction of the lens is 1.35, while the index with a cataract changes to 1.5. which of the following statements is true when light passes from lens to air with a cataract, the critical angle is smaller and TIR is more OR less likely
consider the relationship between TIR and critical angle. the smaller the critical angle gets, the larger range there exists for TIR to occur. as the critical angle gets smaller, TIR becomes more likely
which of the following would be elast effective at forming hypochlorous acid when added to a hot tub with a pH of 3
consider what it means to be in an environment with a pH of 3. the hydrogen ion concentration is very high. the compound that is least effective will be the one that introduces more hydrogen ions into solution accd to Le CHatelier's principle. If hydrogen ions are a product of a certain reaction, then the reaction will be shifted toward the reactants ina n acidic environment. chlorine gas is the only one fo the options presented that creates hydrogen ions in its products, so that will be the least effective
peroxisomes
contain enzymes that produce hydrogen peroxide which is used in the breakdown of lipids and the detoxification of ddrugs CONVERTS DANGEROUS H202 to H20 and O2
oligosaccharide
contains 2-8 monosaccharides formed through glycosidic linjkages (which are dehydration reactiosn)
convert evolution vs divergent evolution
convert evolution = when two species come to psosess analogous structures due to similar selective pressures divergent evolution = selection causes a species to branch out to many species
knockout mice
created by deleting a gene of interest
blood flow rate is analogous to
current
primary adaptive immune response to intracellular pathogens (ex. intracellular parasites) comes from
cytotoxic T cells THIS IS NOT MEDIATED FROM ANTIBODY-GENERATING B CELLS!!!!
2 identical hand guns are fired simultaneously. what is the combined sound pressure level sound pressure level of shot gun discharge = 150 dB (EK physics 93)
decibels are not an additive unit, since they reflect a logarithmic scale of sound pressure 150 decibels means that the sound of a gun firing is 10^15 times more powerful than a sound at the trheshold of human hearing 2 identical hand guns firing would be twice as powerful as the sound of one hand gun firing because in-phase sound waves are additive. this new sound would be 2 X 10^15 times more powerful than a sound at the threshold of human hearing expressed in decibels, this new sound is (10)log10(2X10^15) = 10 X (15 + log10(2)) = 10 X (15 + .3) = 10(15.3) = 153 dB
lysosmes
degrade biologelcal macromolecules by HYDRATION also digests matter brough tin to the cell by phagocytosis ACIDIC INTERIOR!! lysosomic enzymes only funciton in acidic environments
water reactions
dehydration = builds up molecules hydrolysis = breaks down molecules
when a material is undergoing a change in phase, it will always be accompanied by a change in
density and entropy TEMPERATURE IS ALWAYS CONSTANT IN A PHASE CHANGE. BC ADDED HEAT IS USED TO BREAK IntermOLECULAR INTERACTIONS
epimers
diastereomer that differs at just one chiral carbon center
concept of belief perseverence
dictates that when presented with information of varying opinion, people are more likely to believe information that confirms their opinion and discount evidence which refutes it THEREFORE, even when presented iwth info supporting both sides, people tend to confirm and solidify their position
diffusion vs effusion
diffusion = random molecular motion, causing a substance to ove from an area of higher concentration to an area of lower concentration effusion = random molecular motion, causing a substance to escape a container through a very small opeing
one of the primary ways the body gets rid of excess heat
dilation of blood vessels . results in blood traveling out to the extremitites. results in heat loss through areas such as heands and feet NO will triger this
different types of phenotypes
dominate: the allele is expressed in the phenotype no matter what the second allele is recessive: an allele that is not expressed in the heterogenous state incomplete dominance: phenotype of a heterozygote is a blended mix of both alleles (ex. red + white --> pink) codominance: when both alleles are expressed, but NOT blended (ex. the alleles of the gene for blood group antigens that occur on the surface of red blood cells. the allele AB causes A or B antigens to be expressed, while i does not express antigen) pleiotropic = alteration of a gene alters many different, unrelated aspects of the organisms total phenotype polygenic = traits that are influenced by many different genes (ex. height is influenced by genes for growth factors, receptors, hormones, bone deposition, muscle....) epistasis = expression of alleles for one gene is dependent on a different gene (gene for curly hair cannot be expressed if a nother gene causes baldness) penetrance = the likelihood that a person with a given genotype will express the expected phenotype (100 people are homozygous for an allele that is implicated in cancer, but only 20 develop cancer)
why do proteins denature at high temps
due to the effects of entropy as the temperature increases since a folded protein is one particular ordered state out of many, it must be a very low entropy since (delta G = delta H - T delta S), the effect of the change in pKa (EK1 q 9) is likely due to a decrease in the enthalpy of the folded state at higher tempereature. however, as temperature is increased, the entropic contribution to the Gibbs free energy is also increased, which will overwhelm the enthalpy contribution, causing the protein to become less stable
during replication repair, enzymes can reverse an error that would lead to the formation of an oncogene from a proto-oncogene which enzyme is responsible for the last step in dna repair
during base repair a base is excised by a restriction enzyme, replaced by polymerase and finally linked to the bases around it by DNA ligase *primase is not involved in the repair process *topoisomerase relaxes and winds/unwinds DNA for synthesis. it is not directly involved in DNA repair
divalent element
element that forms 2 chemical bonds ex. ca, s
truncated protein
elimination of the N- or C-terminal portion of a protein by proteolysis or manipuation of the structural gene, or premature termination of protein elongation due to a nonsense mutation
endocrine vs exocrine
endocrine - releases HORMONES into bloodstream exocrine - releases CHEMICALS into ducts to outside the body or another surface w/in the body
stomach glands
endocrine: g cells exocrine: parietal, mucosal, cheif g cells = produces gastrin which stimulates parietal cells to secrete HCL parietal cells = secretes HCl following stimulation by g cells chief cells = secretes pepsinogen, which is cleaved to pepsin by HCl mucousal cells = secretes mucous layer that protects the stomach
epithelial vs endothelial
epithelial = surfaces that separate body cavities from the outside environment are lined by simple squamous, columnar, or pseudostratified epithelial cells. Other epithelial cells line the insides of the lungs, the gastrointestinal tract, the reproductive and urinary tracts, and make up the exocrine and endocrine glands. endothelial = type of epithelium that lines the interior surface of blood vessels and lymphatic vessels
mutarotation
equilibrium between alpha and beta fomrs of the sugar
flagella is made from
eukaryote flagella is made from microtubules prokaryote flagella are made from flagellum
probability rule of addition
ex. probability of A or B happening its equal to the probabilty of A added to the probability of B minus the probability of A and B occurirng together
anaerobe ETC?
ex. r. gnavusi is an anaerobe, meaning that it does not require oxygen in its living environment and may therefore utilize an oxidizing agent besides O2 in its electron transport chain
social cognitive perspective
explains the behavior of subjects in terms of their expectations of others BASED UPON EXPECTATIONS OF OTHERS
epistasis
expression of alleles for one gene is dependent on a different gene (ex. a gene for curly hair cannot be expressed if a different gene causes baldness)
which of the following provides the most reasonable evolutionary explanation for fainiting when circulation to the brain is insufficient
fainting is designed to reduce the effects of gravity on blood flow to the brain (***other option also made intuitive sense, but this answer answered the question and was DIReCTLY APPLICABLE OT THE FOCUS OF THE PASSAGE ---- HYDROSTATICS!!) "according to the eq for hydrostatic pressure, P = pgh, pressure is directlly proportional to depth, or in other words, inversely proportional to height. if circulation to the brain is insufficient, fainting makes the individual collapse to the floor. this positions the brain at the same height relative t o the rest of the body, and thus prevents blood pressure in the brain from dropping
terodotoxin found in marine puffer fish competitively inhibits fast voltage-gated sodium channels. which of the following most likely demonstrates the action potential of the SA node when exposed to tetrodotoxin
fast voltage-gated socidum channels have little effect on the SA node, so the action potential would be similar to that under normal conditions. in order for an action potential to be inititated, the membrane potential needs to exceed threshold then realize that the SA node has increased permeability to Na+ so the resting potential would be more depolarized than that of a normal muslce fiber
what does cardiac muscle use for main source of energy
fatty acids although, ketone bodies and lactate can serve as fuel for heart muscle as well
keratin
fibrous protein that makes up hair
EK 1 (116 ) .....genetic similarities...what should the researchers do in order to study the form and function of Hb1
first think about how a scientist studies protein form and function. in order to study this, the scientist needs a large amount of the protein to use in experiments. the question is really asking: how can scientists purify a large amount of Hb1? Best answer: use an expression system to produce a large quantity of Hb1 expression systems use another organism or synthetic biotechnology systems to create a large amt of a protein of interest. there is precedent for using animal systems to synthesize human proteins, such as the use of cows to make therapeutic insulin ****genetic analysis is not the best way to study protein form and function. it would be beter to directly compare the two proteins rather than the round-about genetic analysis
membrane is fluid mosaic
fluid = held toghether by WEAK forces and molecules move relative to eachother laterally but VERY DIFFICULT TO FLIPFLOP mosaic = asymmetrical layout of proteins in the membrane
humanist perspective on therapy
focus on self-actualization and helping patients become more complete and fulfilled individuals
freudiean perspective on therapy
focused on the unconscious
trait perspective
focuses on measuring aspects of personality that are able to be grouped into mpatterns of thought and behavior
FAE
fundamental attributional error overvalues disposition and undervalues environment when attributing explanations for behavior
researchers use gel electrophoresis to separate a sample composed of four proteins which protein moves the farthest down the gel
gel electrophoresis separates proteins based on size, and the smallest proteins travel the farthest
cDNA library
generated by reverse transcribing mature mRNA, resulting in a DNA copy of the gene that lacks any introns that may have been spliced out of the mRNA during post-transcriptional processing the cDNA plasmid contains a copy of the gene that is COMPLEMENTARY to the mature mRNA that has been post-transcriptionally processed the cDNA will not contain telomeres, as telomeres are repetitive sequences located at the ends of chromosomes, and would not get transcribed
mitochondria contains its own
genome of single circular DNA -encodes some rRNA, tRNA and several proteins
the increasing likelihood that a person calling a tech support center will speak to someone in a different continent is an example of
globalization
what type of protein class generally act as enzymes
globular proteins someimes ribonucleic acids (ex. rRNA in ribosomes, snRNA in spliceosome)
ligase
glue DNA backbone back together
glycogen is 1. polymer 2. disccharide 3. polysaccharide ??
glycogen is the storage form of glucose in animals. it is a glucose polymer, and more specifically is a polysaccharie, as it is composed of repeated units of sugars. it is not composed of only two glucose units, so it is not a disaccharide
heterochromatin vs euchromatin
heterochromatin = regions that are tightly packed and not transcribed EUchromatin = regions of chromosomes that are LOOSEly packed and activley transcribed
if the body has excess glucose stores, which electron transfer intermediates are likely to accumulate? how does this change if the body is energy depleted
high glucose - accumulation of NADH and FADH2 depleted - accumulation of NAD+ and FAD+2
deviation from ideal occurs at
high pressure and low temperature (real world is COLDer and high pressure) at these conditions the molecules are "squished" together. when the gas molecules are so close together, they experience intermolecular interactions. also the molecular volume becomes significant when the total volume is squicshed down so much. the intermolecular attractions will cause collisions to be sticky and inelastic.
homologues structures vs analogous structures
homologues = physical features shared by two species that are the result of a common ancestor analogous structures = serve the same function in two species but NOT A COMMON ANCESTOR!
cellular shortening is used as a measure of
how much a cardiac cell contracts the degree of cell contraction correlates with intracellular calcium. higher intracellular calcium leads to increased contraction adn thus increased cellular shortening eliminate a and b because although cardiac cells require extracellular calcium to contract, the actual degree of contraction is determined by the concentration of INTRACELLULAR calcum
post translational modification of proteins occur
in GA primarily in the Cis stack
which of the following lists a pari of physiological changes that would both be likely to increase the rate of...
in general an increase in substrates that preced pyruvate in glycolysis, or a decrease in substrates that follow it
all translation starts
in the cytosol the majority is then injected into RER, where it finishes translation
fehlings reaction
in this test the presence of aldehydes but not ketones is detected by reduction of the deep blue solution of copper 2+ to a red precipitate of insoluble copper oxide THIS TEST IS COMMONLY USED FOR REDUCING SUGARS BUT IS KNOWN TO BE NOT SPECIFIC FOR ALDEHYDES
golbalization
includes the increasing interdependence between people in different regions of the world
for every 10fold increase in intensity, what happens to dB
increase dB + 10 ex. if increase 20 decibels -0--> 10^2 times more intense!
if argon is used instead of helium for GC, retention times will
increase slightly bc a heavier gas travels with lower veloicty at a given temp than a ligheter gas
why is the blood flow velocity in the capillaries significantly lower than the blood flow velocity in the arteries
increasing the TOTAL (net) cross-sectional area decreases fluid velocity
hawthorne effect
individuals change their behavior because they are aware that they are being studied
induction signaling vs signal transduction
induction signaling = a signaling cascade in development which changes the structure or function of developing tissues through chemical mediators signal transduction = occurs when an extracellular signaling molecule activates a specific receptor located on the cell surfae or inside the cell. in turn, this receptor triggers a biochemical chain of events known as a signaling cascade ***induction must then just be a susbset of transduction
ethical research guidelines place great emphasis on
informed consent PRIOR to the commencement of a study if there is potential for emotional or physical harm to the participants in the study
inhaling more air than normal effects acclimatization....
inhaling more air than normal will compensate for the fact that the inhaled air has less oxygen than normal
squalene
is the triterpene which is the biochemical precursor to the whole family of steroids. An oily substance produced by the shark's liver. helps offset the shark's high density.
thoracic duct
it drains into the systemic (blood) circulation at the left subclavian vein. It also collects most of the lymph in the body other than from the right thorax, arm, head and neck which are drained by the right lymphatic duct.
adding a catalyst will affect speed and amount of products HOW?
it will inc both the forwward and backward reaction rates but it will NOT cause a net inc in the amt of products being formed
the partial pressure of a solute just above the solution's surface is directly proportional to
its concentration
catalytic efficiency vs kcat
kcat = Vmax / [E] catalytic efficiency = Kcat / Km
kcat vs catalytic efficiency
kcat = vmax / [E] catalytic efficiency = kcat/km
reproductive isolation
keeps species separate two types: pre-zygotic and post-zygotic
7 taxonomic categories
kingdom, phylum, classs, order, family, genus species
chomatography is preferred over electrophoresis when
large amounts of proteins are being separated
lipid mobilization
lipids are mobilized from adipocytes by HORMONE SENSITIVE LIPASE lipids are mobilized from lipoproteins by LIPOPROTEIN LIPASE
different funciton of SER
liver = detox and glycogen breakdown gonads = steroid synthesis
restriction site
locations on a DNA molecule containing specific (4-8 base pairs in length) sequences of nucleotides, which are recognized by restriction enzymes / restriciton endonuclease
enzyme specificity
lock and key = enzyme active site has aspecific shape that it's substrate fits into induced fit = the shape of both the enzyme and the substrate are altered upon binding
waxes
long chain fatty acids that form esters with alcohols solid at room temp used as protective layers and honeycomb
pili
long projections on bacterial surface involved in attaching to different structures
question 33 EK1
lower density will be displaced by higher frequencies lower tension will be displaced by lower frequencies **v = sqrt (bulk modulus/density)
catalysts change the kinetics of a rxn by
lowering the activation energy, but they do NOT change the equilibrium constant both forward and reverse rxns increase in speed as a rsult there is no net change in concentration of either products or reactants; the equilibrium constant K does not change
which germ layer of the gastrula gives rise to cardiomyocytes, the specialized precursor's cells of cardiac muscle
mesoderm
function of peroxisomes
metabolize lipids and toxins using hydrogen peroxide oxidation reducton reactions
the first amino acid in many proteins is
methionine this is because the start codon for translation codes methionine
gene therapy
method of curing genetic deficiencies by introducing a funcitonal gene with a viral vector
cytoskelton proteins
microtubuels =involved in mitosis, transport, cilia, flagella and motor proteins microfiliaments = made of actin and involved in gross movement of ENTIRE cell (muscle contraction, cytokinesis, amoeboid motion) intermediate filaments = structural suppoort
if non disjunction happens in meiosis 1, you ened up with... if in meiosis 2, yoou end up with what is trisonmy 21
miosis 1 = 2x(n+1) and 2x(n-1) meiosis 2 = n, n, n+ 1 and n-1 trisomy 21 (down syndrome, where individuals have 3 copies of the 21 chromosome) is caused by having an extra chromosome (n+1) which can be seen with non disjunction in both meiosis 1 and meiosis 2. the chance is higher if nondisjunction occurs in meisos 1 but it could also occur in meiosis 2
types of mutations
missense silent frameshift - deletion, insertion
how is mixed inhibitor different from noncompetitive
mixed binds to either the enzyme or enzyme-substrate complex BUT HAS DIFFERENT AFFINITIES FOR EACH (noncompetitive binds both equally) if the mixed inhibitor prefers the enzyme, it will increase Km if the mixed inhibitor prefers the enzyme-substrate complex, it will decrease Km ***non-competitive inhibitors are a form of mixed inhibitor!
sds separates proteins by
molecular weight
surface tension arises because
molecules at the surface of a cluster experience a net force inward due to intermolecular attractions
eukaryote transcription regulation
monocistronic more complicated regulation transcription factors: bind in region close to promoter - DNA-binding domain: binds to a specific nucleotide sequence in the promoter region - activation domain: recruits transcription factors or regulatory proteins (RNA pol, histone acetylases) enhancers and repressors = regulatory proteins used by eukaryotes BIND FAR FROM PROMOTER gene duplication = opening the gene with helicases and permitting DNA replication only of THAT gene regulation of chromatin structures ----histone acetylation: acetylation of lysine decreases the positive charge on lysine residues and the interaction of the histone with DNA (loosens chromatin) ---> INCREASES transcription ------DNA methylation = addition of methyl group to cytosine and adenine ---> decreases gene expression
behavioral therapists focus
more on action than cognition
components of small intestine
most of the digestion occurs in the DUODENUM most of the absorbtion occurs in the JEJUNUM and ILEUM
collagen
most prevalent proetin in the human body as a whole
mysoin is a
motor protien associated with muscle cells
what would you expect to increase in a tumorigenic cell
mrna synthesis ribosomal assembly cell division
in contrast to the ionotropic nicotinic acetylcholine receptors, muscarinic acetylcholine receptros are coupled to G-proteins to produce an inhibitory secondary messenger cascade when activated. these receptors are most likely to be found
muscarinic receptors use acetylcholine, and the subtypes in the passage are inhibitory. therefroe, they would be found in a location that is modulated by inhibition. the sympathetic nervous system and the neuromuscular junction both activate downstream tissues, so eliminatate choices B and D. in addition, although the parasympathetic system generally has an inhibitory effect, some effectors of the system, such as the intestines, are not inhibited, so the generalization in choice C cannot be made therefore, the muscarinic receptors must be between the postganglionic neuron of the parasympathetic nervous system and an effector which is normally inhibited by parasympathetic activity such as the heart
organic compound
must contain carbon bound to hydrogen (and can possibly have other elements) ex. Carbon dioxide is inorganic, glucose is organic
mutualism vs commensalism vs parasitism vs predation
mutualism = both species benefit comensalism = one species benefits, and the other is neither benefited or harmed parasitism = one species benefits, one is harmed predation = one species hunts (and presumably consumes) the other
when/why does DNA supercoiling occur
one reason is the strain caused by the unwinding of doublestranded DNA, so DNA supercoiling occurs in situations that require the DNA to be unwound and opened up like DNA replication and transcription. DNA supercoiling also occurs during DNA compaction. In order for an organism's genome to fit into the space of a nucleus, DNA must be heavily compacted around histones. Chromatin remodeling is a process that occurs as part of DNA organization in the nucleus, so this is also correct
which of the following would least likely occur as a result of inputting one acetyl-coa into citric acid cycle
one turn of the CA cycle produces 3 nadh, 1 fadh2, and 1 atp. both nadh and fadh2 are dinucleotide structures that result from the reduction, or transfer of electrons, to NAD+ and FADH+, respectively. ATP is produced by phosphorylation of ADP Each turn of the CA produces two CO2 molecules The high proton gradient in the intermembrane space of the mitochondria is formed as a result of the ETC, not during the CA cycle, making choice C the best answer. though it could occur, it is the most far removed form the action in the question
prokaryote transcription regulation
operon = operator, promoter, gene (operator = binding site for repressor) enzymes for anabolism are produced when the item they make/ the anabolite is SCARCE!! enzymes for catabolism are produced when the item they breakdown (substrate) is abundant
memory problems resulting form issues with signal transmission between neurosn could also have been caused by which of the following nervous system malfunctions 1. axon demyelination 2. decrease in resting K+ channel density 3. withdrawal of postsynaptic nicotinic acetylcholine receptors 4. decrease in voltage gated Ca2+ channel density
options 1 and 4 are both in three of the answer choices so it is very likely that they are correct. start by focusing on 2 and 3. looking at 2, the resting potential is established by ion concentrations and not by channel density so this should not affect action potential initiation. next, loss of postsynaptic receptors would increase the amount of neurotransmitter release necessary to initiate an action potential and would interfere with normal functioning, so option 3 must be in the answer option 1 is true because saltatory conduction can occur in the axon because the myelination prevents loss of charge between nodes of ranvier, and without myelination, conduction would occur much more slowly option 4 is true because voltage gated Ca2+ channels are required for neurotransmitter release and are necessary for action potential transmission
vitamin
organic molecule that cannot be synthesized by the body
chimeras
organisms that contain cells from two different lineages (such as mice formed by integration of transgenic embryonic stem cells into a nourmal mouse blastocyst)
dalton's law
partial pressure of A = (mole fraction of A) X (total pressure) - Ptotal = sum Pi = sum (mole fractions ) X total pressure -
absolute pressure of somethibng submerged in the ocean
pgh + atmospheric pressure ***pgh is the gauge pressure because it ignores the amtmospheric pressure above the fluid
phosphoric acid is titrated with a strong base, which of the following is the predominant compound present at the third EP
phosphate ion
Na+/ K+ atpase
plasma membrane protein in every cell pumps 3 Na+ out of the cell and 2 K+ into the cell WITH the hydrolysis of ATP potassium leak channels =- K is able to leak back out; the ion of positive charge causes the inside of the cell to have a negative charge RELATIVE to the outside (CREATES AN ELECTRIC RESTING POTENTIL of -70mV)
episomes
plasmids that can be integrated into the genome
one of the classic symptoms of type 2 diabetes is...? why?
polyuria = an increase in urine output higher than normal amounts of glucose in the urine means that the urine osmolarity will be higher than usual. this will results in less reabsorption of water from the filtrate in the nephrons. a possible explanation for this is that the presence of glucose in the renal tubule directly causes a decrease in movement of water through cells in the descending limb of the loop of henle
what will give positive benedicts or tollens test? what will give neg
positive = hemiacetal or hemiketal (acetal vs ketal depends on original sugar) negative = acetal or ketal..NO HEMIACETAL OR HEMIKETAL ON ANOMERIC CARBON
intensity of sound is measured as a function of
power per unit area
pre zygotic barriers (5 )
prevent the formation of the hybrid zygote 1. ecological barriers: the species are separated geographically 2. temporal barriers: the species mate at different times 3. mechanical : physically cannot mate 4. behavioral: they do not have matching mating rituals 5. gamete: the sperm and the egg don't fuse
post zygotic barriers (3)
prevents 1. development of hybrid individual 2. survival of hybrid individual 3. reproduction of hybrid individual
primary active transport vs secondary active transport
primary - requires energy in the form of ATP secondary - requires an existing favorable ion gradient. seconary active transport can be further classified as symport or antiport
alternative splicing
primary transcript of hnRNA may be spliced together in different ways to produce multiple variants of proteins encoded by the same original gene
bile is produce / stored where
produced by the liver stored in the gallblader BILE IS USED TO EMULSIFY FAT
confabulation
production of a distorted / false memory without the intention to deceive it is a common symptom of korsakovs syndrome
start codon prokaryotic vs eukaryotic
prokaryotic = fMet start codon eukaryotic = Met start codon = AUG!!
taxol inhibits the growth of cancer by stabilizing microtubules. which of the following cellular processes is likekly most affected
prophase of mitosis microtbule movement plays a large role in formation of the mitotic spindle during prophase.
protein denaturation disrupts..., ...., and ....but does not disrupt....
protein denaturation disrupts secondary, tertiary and quaternary structure while leaving primary structure, or amino acid sequence, intact
nuclear matrix
protein scaffold to support and provide structure
transversion mutation
purine -> pyrimidine or pyrimidine --> purine in DNA can only be reversed by a spontaneous reversion
pyranose vs furanose
pyranose = sugars in a 6 membered ring structure FFFFuranose = sugars in a FFFFIVE membered ring
mitochondria is the site of
pyruvate dehydrogenase krebs cycle oxidative phoshporylation
what units oof protein structure are lost during denaturation
quaternary, tertiary and secondary
a patient diagnosed with MCAD deficiency and no other health conditions is found to have a father that carries the same mutation, but a mother without evidence of mutation when a buccal swab is taken which of the following is the most likely reason
question 23 Kaplan review test 2 "a single event is almost always more likely than multiple events. therefore the consideration should be isolated to events that would occur before division of the zygote. in this case, any loss of the fully functioning gene is likely to cause the symptoms. however, this still leaves maternal MCAD loss and maternal MCAD mutation as possibilities. to distinguish between them, recognize that the child does not have any other medical conditions. monosomy in any chromosome, as would result from maternal nondisjunction resulting in gene loss, is a serious medical condition
types of RNA
rRNA - forms ribosomes by aggregating with ribosomal proteins mRNA - codes for the order of AAs within a peptide chain tRNA - physically links nucleic acids with amino acids microRNA - small, non-coding class of RNA that plays a role in gene regulations
which of the following has the most stable conjugate base
really asking what is the strongest acid the more stable the conj base, the stronger the acid acid strength is increased by the inductive effect of electron withdrawing groups on the neighboring carbon atoms
the inhibition of an action potential via muscarinic acetylcholine receptros is most likely the result of
recall that depolarization refers to making the interior of the neuron more positive, which brings the potential within the cell closer to the threshold and at a sufficient level will initiate an action potential. thus to inhibit an action potential, the neuron must be becoming hyperpolarized when positive charges move into the cell, the cell becomes depolarized regardless of what ion is influxing. It can be concluded that efflux of K+, the movement of K+ out of the cell, hyperpolarizes the cell and inhibits an action potential
strong stimulation of the vagus nerve can block transmission of the cardiac impulse through the A-V junction. however, in a phonomenon called ventricular escape, the ventricles usually begin beating with in 5 to 20 seconds. which of the following is the best explanation for ventricular escape
recall that heartbeats are initiated at the SA node, which creates an action potential that is transmitted ot the AV node. this is the only pathway for normal heartbeat generation and cannot be bypassed therefore, if the AV juncion were blocked, SA signaling would have no effect choice a is difficult to eliminate because it appeals to an intuitive way of reasoning. choice C is a better answer choice than A though because it utilizes information mentioned in the passage that the Purkinje fibers have autorhythmicity and could initiate a heartbeat in the absence of external stimulus
do red blood cells have a nucleus
red blood cells do not contain nuclei or organelles they do not contain DNA and cannot synthesize any RNA, consequently cannot divide and have limited repair capabilities. the inability to carry out protein synthesis means that no virus can evolve to target mammalian red blood cells
anticholinergic
reduces the effectiveness of the acetylcholine system something that is anticholinergic will be unlikely to increase the levels of an enzyme that produces acetylcholine
demand characteristics
refer to circumstances in which participants guess the hypothesis of the study and change their behavior to mathc that hypothesis ***REWUIRES A HYPOTHESIS
demographic transition
refers to a change in the birth rates and death rates of a population first death rate dec, then birth rate dec
innate behavior
refers to behavior that occurs based on "hard-wiring" of the nervous system and is independent of anybody else's behavior
systematic error
refers to error in measurement --- with systematic error, the error is consistent for each measurement
(EK physics 106) the scattering observed in the lenses of cataract patients is most analagous to refraction TIR diffraction diffuse refraction
refraction occurs when light bends as a result of changing medium. this does not generally scatter the light, so choice A is a weak answer. TIR is fairly similar to reflection off a plane surface, where light stays parallel. so b is unlikely. diffraction is the bending of light as a result of there being a boundary in the light's path that is close in size to the wavelength of the light diffuse reflection is reflection off a nonplanar surface, leading to scatering of light rays, so D is the best answer!!
nucleolus
region of nucleus where ribosomal rRNA are produced and ribosomes are assembled
behaviorist perspective
related to external stimuli experienced by the person
the enolate anion is stabilized by
resonance, which delocalizes the negative charge to the electronegative oxygen
right ventricle vs left ventricle
right ventricle generates less force and supply blood to pulmonary circulation left ventricle generate more force to supply blood to systemic circulation
deviations from roult's law (2)
roults law = x(a) X P(a) 1. if intermolecular attractions between a and b are weaker than intermolecular attractions between A and A or B an B, then the molecules will escape from the liquid solution into the gas phase MORE EASILY than they would from pure A or pure B ----****the partial vapor pressure will be HIGHER than predicted by roult's law 2. if intermolecular attractions between A and B are stronger than between A and A or B and B, ---> ***Vapor pressures will be LOWER than predicted
purpose of a salt bridge
salt bridges are a necessary component of GALVANIC CELLS they release anions and cations into the separate half cells to counteract the buildup of charge created by the current flow THEY PREVENT CHARGE BUILDUP IN GALVANIC CELLS
saturated vs unsaturated
saturated stack more closely - decrease fluidity - butter unsaturated = increased fluidity
proteins synthesized by ribosomes bound to RER
secreted into extracellular environment, integral proteins, in membrane interior of ER golgi and lysosomes
principle of segregation vs. law of independent assortment
segregation = the two alleles of a parent are separated and passed on to the next generation SINGLY independent assortment = the alleles of one gene will separate into gametes INDEPENDENTLY of another gene (THIS ONLY HOLDS IF ALLELES ARE ON DIFFERENT CHROMOSOMES!)
absoprtion of lipids from diet
short chained fatty acids are absorbed across the small intestine into the blood long chained fatty acids are absorbed as micelles and assembled into chylomicrons for release into LACTEALS of the lymphatic system and REENTER the bloodstream via the thoracic duct
primary protein of hair
since hair is a specialized form of the epidermis, it too consists of dead cells after the cell dies whats left is primarily keratin
colloid vs solution
solution = things are mixed at the moelculear level and will ALWAY stay mixed colloids = things are mixed at a "semi-molecular level" with solute aggregates that are really really tiny. colloids will stay mixed until you centrifuge it ex. sollution = dissolving solute into solvent ex. colloid = 1. milk, 2. shaking water and oil vigoursouly = emulsion = colloid ex
some g proteins activate.... which causes a cascade resulting in....
some g proteins activate phospholipase C which causes a cascade resulting in Ca 2+ influx
nondisjunction
sometimes homologous chromosomes fail to separate during meiosis 1 and sometimes during meiosis 2 sister chromatids fail to separate RESULT IS: miosis 1 = 2x(n+1) and 2x(n-1) meiosis 2 = n, n, n+ 1 and n-1
southern vs northern blot vs western blot
southern = used to identify known DNA sequences in a large population of DNA northern = same as souther blot but it identifies RNA (I R from the NORTH) western = can detect proteins in a mixture of proteins
anaphase mitosis
spindle fiber shortens and sister chromatids are pulled apart
copper 2+ is what color? when it is reduced what color is it
starts out as BLUE when it is reduced / when it oxidizes the carbonyl it turns RED
rate of reaction is dependent on
substrate concentration temperature --- kinetics increases as temperature increases until a certain point where the enzyme denature pH - enzyme functions within a certain pH range
disaccharides
sucrose lactose maltose
solubility product constants are determined to be greater than their solubility product constants at standard conditions. what is the most likely explanation for this
temperature is the only thing that can change Ksp (any equilibirum constant) *common ion effect will not affect the solubility product but COULD afffect molar solubility
when an infection occurs, adaptive immune cells....
that CAN respond to a SPECIFIC pathogen are activated, and undergo CLONAL EXPANSION **if for somereason, antibodies become less specific, more will be activated and clonal expansion will actually be increased (adaptive immune cell proliferation in response to a single pathogen would INCREASE)
Linkage is based on
that the law of indepeendt assortment does NOT HOLD for alleles on the SAME chromosome! ex. if you have two genes located on chromosmoe # 12, they MAY NOT display independent assortment LINKAGE IS THE EXCEPTION TO THE LAW OF IDNEPENDENT ASSORTMENT: WHEN GENES ARE LOCATED ON THE SAME CHROMOSOME, THEY MAY DISPLAY LINKAGE AND MAY NOT ASSORT INDEPENDENTLY!!
a greater heat of combusion impolies
that the structure is less stable
chargaffs rule
the amount of guanine is equal to the amount of cytosine and the amount of adenine is equal to the amount of thymine
gene knockdown
the artificial manipulation of gene expression - causing one or more of an organism's genes to be reduced
effect of NO in arteries around the circulatory system on venous blood volume
the blood is pulled out of venous circulation and now more voluminous arterial side so volume does decrease
using reverse transcriptase PCR (RT-PCR) a cDNA segment is generated. this segment is then amplified using traditional PCR, creating DNA strands complementary to the cDNA segment. if the RT-PCR experiment was performed with a RNA template reading 5'-GGAUUCG-3', what would the resulting amplified sequence be?
the cDNA complementary to the RNA template would be 3'-CCTAAGC-5' . From the cDNA, the amplified transcript would be 5'GGATTCG-3'. It is important to remember that the 5' end of the amplified segment matches the 5' end of the original RNA template
(EK physics 87) a +1 nC charge flows up the spine of a person towards the brain. which of the following is true if there is a HVT line directly above the person and the potential due to the line decreases as altitude decreases
the charge is slowed because positive charges are pushed from high to low potential
hardy-weinberg equilibrium assumption
the conditions for the HW equilibrium are that the frequency of alleles in the gene pool change over time. and include the following assumptions 1. no mutation 2. no natural selection 3. random mating 4. no migration 5. population is large to rpevent random drift in allele frequencies
"what oversight did the student make when concluding that the continuity equation was being violated in the experiment"
the continuity eq cannot be violated in hydrodynamics. the oversight in this experiment is assuming that one artery will continue in series with one arteriole and then one capillary, which is false. in fact, one artery branches into several arterioles which further branches out into millions of capillaries. the total cross sectional area of all these capillaries FAR EXCEEDS the cross sectional area of the one artery they all branch out from. since the capillaries have a NET greater cross-sectional area than arteries, blood flows slower through the capillaries!!! THIS IS CONSISTENT WITH THE CONTINUITY EQUATION
the solubility product represents
the dissociation of that compound in water the equilibirum constant for this rxn is calculated by writing out the concentration of the products raised to the power of their coefficients and dividing by the concentrations of the reactants raised to the power of their coefficients. REACTANTS AND PRODUCTS IN THEIR SOLID OR LIQUID STATE ARE LEFT OUT OF THE EQUILIBRIUM EXPRESION!!!
nondisjunction
the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei.
a device is grafted onto the basilar membrane of a gerbil, which decreases the elasticity along the length of the membrane. which of the following would occur
the gerbil would be able to detect lower frequency sound "think of the basilar membrane as a vibrating string, where elasticity, or the ability to bounce back, is similar to tension. the higher the tension in the string, the higher the frequency of vibration (think of tuning a guitar string; pulling it tighter makes the pitch higher). if the tension in the basilar membrane is decreased, the frequencies at which it vibrates will also decrease, shifting the gerbil's range of hearing to lower frequencies
when is the image larger than the object with a concave mirror
the image will be larger than the object when the object is within the radius of curvature
ideal gas laws are derived from
the kinetic theory of gases
the more specific a binding site is
the less likely it is that the binding site binds more than one type of molecule
effective nuclear charge (z eff)
the net positive charge experienced by the valence electrons increases up and to the right z effective = atomic number - s so basically in the same row the distance is about the same of electrons (principla quantum nuber) but the number of protons significantly changes. so a halogen will have the most protons pulling essentially the same electrons which means its effective nuclear charge will be greater
patients with advanced ovary cancer likely have abnormal production of
the ovaries are an important site of hormone synthesis, and since cancerous tissues often lose appropriate function, a patient with SEOC might have dysfunctional hormone production in her ovaries. rembmver that the three hormones made in the ovaries are estrogen, progesterone and testosterone up to 50% of the testosterone in a female system is synthesized in the ovaries, so choice d is the best answer
an aq solution of 1 M glutamate is titrated with concentrated HCl. There will be an equal concentration of glutamic acid and glutamate when the pH equals
the pKa of glutamic acid glutamate is the conj base of glutamic acid. from H-H and definition of pKa, it can be determined that the concentration of conj acid and base pairs are equal when the pKa equals the pH
what organ is involved in neutralizing gastric acidity
the pancreas....it releases negatively charged bicarbonate ion (hco3-.....base) into the duodenum
what is the direction of Na+ movement facilitated by Na+/Ca2+ exchangers present in the SA node
the passage notes that the SA node has a higher than normal permeability to Na+ which means that more extracellular Na+ is able to enter the cell than usual. Intracellular Na+ would be elevated, not extracellular Na+, so eliminate choices B and D CHoice c would go against the electrochemical gradient so this can be eliminated this leaves only A: Na+ out of the cell because of elevated intracellular Na+
frequency of recombination betwen two genes is proportional to
the physical distance between the two genes along the DNA molecule (the farther apart the more likley that recombination will occur) recombinaton frequency = number of recombinant phenotypes / total progeny (distance in chromosomes)
release of acetylcholine from neurons involves the simultaneous release of between 1000 and 10000 serotonin molecules werotonin release illustrates which of the following transport mechanisms? primary active, secondary active, facilitated diffusion, or exocytosis
the question stem notes that it involves the simultaneous release of a large number of serotonin molecules. this means the correct mechanism cannot involve transfer of one molecule at a tie. among the listed choices, only exocytosis - in which a vesiclue fuses with the cell membrane and expels its contents = transfers large numbers of molecules **** primary, secondary active transport & facilitated diffusion - would all move only a small number of serotonin (usually 1 to 3) across the cell
Acid anhydrides are formed via
the removal of water from the reaction of two carboxylic acids *acid anhydrides are highly reactive
scientist remove both tympanic membrane and ossicles from the auditory canal of a rodent, thus allowing sounds waves to directly influence depolarization of stereovilli how will the rodent's hearing pathway be affected
the rodent will be less sensitive to nearby sounds as well as those further away as sound waves travel from the wide tympanic membrane to the relatively narrow ossicles, there is an amplification in the intensity of the sound waves without these structures, the intensity of sound will be less than normal, limiting the rodents ability to hear all sounds, whether nearby or far away
the speed of sound is proportional to
the square root of a medium's bulk modulus so sound travels fastest in a solid
km
the substrate concentration at which the reaction rate is equal to 1/2 vmax --this does not change with the changing enzyme concentration ---indicator of enzyme affinity
boiling point
the temp at which the vapor presure of the soln is qual to the pressure over the solution
enzymes stabilize
the transition state ex. if the transition state had a negative charge, the enzyme active site would likely have a positive charge
as glucose, a reducing sugar, is oxidized during Fehling's reaction, how is the equilibrium between hemiacetal D-glucose and linear D-glucose shifted
there is a shift favoring the replacement of the linear form of glucose "the ring and linear fomrs of glucose are in equilibrium initially. however, only the linear form can undergo oxidation. hence, as the fehling's reaction progresses, more and more of the linear form of glucose gets consumed, causing the equilibium reaction between the linear and ring form of glucose to shift towards linear glucose
Look at picture in previous flashcard. how do the volume displacements per second at points a, b and c compare to eachother
they are the same at points a, b and c *the continuity equation dictates that while the velocity of fluid at point C is greater than at points A and B due to the smaller cross-sectional area at point C, the volume displaced per second must be the same flow = Av
(EK physics 107) light identical to that used in x-ray diffraction is projected through two slits that are 1 nm apart and then onto a screen. which of the following is true of the resulting band patter? 1. a max occurs on the screen directly across from the point between the two slits 2. the angle between the light rays going to the zeroth order and the second order maximum is 90 degrees 3. only maxima appear on the screen
this question sets up a double-slit diffraction scenario. the light used has a wavelength of .35 nm based on the information in the passage. next, the distance between the slits is 1nm. double slit- diffraction is governed by the equation: dsintheta = m(lambda) , where d is the distance between the two slits, theta is the angle between the 0th order and mth order maxima, m is the order and lambda is the wavelength of light used for all double slit diffraction, there is a maximum called the 0th order maximum directly across from the middle of the two slits. this makes option 1 likely to be included in the answer. the zeroth order maximum is directly across on the screen, so those light rays are basically traveling horizontally to the screen. for the angle to be perpendicular the second order maximum would have to be on the slide with the slits, which is not the case. all maxima form on the screen across form the light source and the slits. this means option 2 is unlikely. rule out opiton 3 since since double-slit diffraction results in a series of alternating bright bands, or maxima and dark bands, or minima. ONLY 1!!!
effect of high incidence of severe disease in the sample population on validity of study's conclusion
this sia slso a confounding factor that might have affected mortality rates, as no data was given suggesting comparable levels of disease in both groups ex. thus, the claim that sodium bicarbonate administration is associated with higher mortality rates is weaekned because severe disesase (THAT CAN OFTEN RESULT IN DEATH) may have influenced the outcome
mendellian genetic test cross
to deduce the genotype of an individual, corss it with a homozygous recessie F1 generation: progeny of test cross
what is the role of the Purkinje fibers in cardiac contraction
to synchronize the contraction of ventricular cardiac muscle
totipotency
totipotency is the ability of a cell to develop into any mature cell type. it is generally retained only in the very early embryo. once the cell has already differentiated into speciifci tissue types those cells are no longer totipotent.
proteins synthesized in RER
transported in vesicles to the GOlgi, then the plasma membrane or lysosome
glycerol is the byproduct of...
triglyceride metabolism, which yields one glycerol molecule and 3 fatty acid molecules
phospholipid
two fatty acid chains and a phosophate attached to glycerol through ester linkages
dimer receptros are characteristic of what type of receptor
tyrosine receptor kinases
types of carrier proteins
uniport = transport only one molecule symport = carry two substances across the membrane in the same direction antiport = carry two substances in opposite directions
denaturing agents and forces disrupted urea salt or change in pH mercaptoethanol organic solvents heat
urea = disrupts hydrogen bonds salt or change in pH = disrupts electrostatic bonds mercaptoethanol = disrupts disulfide bonds organic solvents = disrupt hydrophobic forces heat = disrupts all forces
specificity markers
used in an experiment to ensure that cancer treatment is only taken up by certain cancer cells (glial cells in the experiment)
defensive attribution
used to describe a set of beliefs that are held to alleviate concern over the chances of a callamity befalling on them
allosteric regulation
using a small molecule to regulate an enzyme by binding to an allosteric site --generally, this is noncompetitive and reversible -alters the conforation oft he enzyme
vapor pressure depression
vapor pressure = the pressure exerted by gaseous phase of a liquid that evaporated from the exposed surface of a liquid 1. as intermolecular forces, increase, vapor pressure decreases 2. as temperature increases, vapor pressure increases 3. as atmospheric pressure increases, vapor pressure REMAINS THE SAME!! 4. as solute concentration increases, vapor pressure decreases
proteins from RER go...
vesicles from RER fuse with cis stack, where they are modified then transferred through vesicles to the medial stack where further modification occurs and then passed to the trans stack where they leave the golgi complex (what faced into the vesicle now faces out of the plasma membrane!)
(EK physics 73) if the total electric current reaching earth's surface is nearly constant at 1800 A, approximately how much electrical energy is dissipated each second by the atmosphere
voltage is given as 400,000 V Power = IV = (1.8 x10^3)(4x10^5) = 7.2 x 10^8
water phase diagram vs other phase diagrams
waters phase diagram has a negative slope for the line separating solids and liquids. compare this pic to previous flashcards
Which of the following proteins would be inactivated or downregulated by active PI3K signaling? A. BAD and p21 Correct Answer B. IKK and p27 Your Answer C. mTOR and HGFR D. CREB and ATP-CL TPR R#2 P#6
A. Based on information in the passage, PI3K signaling (via Akt activation) stimulates cell growth and proliferation, and inhibits apoptosis. Therefore, proteins that inhibit cell growth and proliferation or that promote apoptosis would be downregulated. BAD is pro-apoptotic, and p21 inhibits the cell cycle, so PI3K signaling would inhibit both of these (choice A is correct). p27 would most likely be downregulated in order to promote cell cycle progression, but since IKK leads to the degradation of an anti-survival protein, it promotes survival and would be upregulated (choice B is wrong). Both mTOR and CREB, that lead to the activation of pro-survival or growth genes would be upregulated (choices C and D are wrong). *THIS INFO ALL COMES FROM THE PASSAGE
The ball in trial 1 does not register a final speed on the laser surface velocimeter because it doesn't reach the right side of the frame. Which of the following best approximates its velocity upon striking the bottom of the frame? A. 3.32 m/s Correct Answer B. 4 m/s C. 5.27 m/s Your Answer D. 5.99 m/s
A. Choice C and D can be immediately eliminated because a ball that starts at rest will always have less kinetic energy (and therefore speed) than a ball that starts in motion if both gain the same kinetic energy during their trip, as trials 1 and 3 do; put another way, the acceleration each ball undergoes is perpendicular to the initial velocity, so it only adds to the magnitude to the total speed. Choice B would be correct if the charged balls slid on a frictionless surface, so that all of their kinetic energy was translational: (1/2)mv2 = qEd → v2 = 2qEd / m = 2(2 × 10-2 C)(8 N/C)(0.5 m) / 10-2 kg = 16 (m/s)2 → v = 4 m/s. However, because as the passage states the balls are rolling and not sliding, some of their total kinetic energy must be rotational (the precise fraction isn't necessary). Thus their translational velocity upon striking the bottom edge of the frame must be less than this. Choice A is correct. Note that the final speeds given in the last column of Table 1 are consistent with this fact: they are less than one would expect if the only form of kinetic energy were translational.
Once radiolabeled for detection, which of the following amino acids would be LEAST likely to accurately measure the amount of non-procollagen secreted? A. Hydroxyproline Correct Answer B. Tyrosine C. Cysteine D. Tryptophan Your Answer
A. Hydroxyproline is considered a non-proteinogenic - or, "unnatural" - amino acid in the sense that it is not typically found in the proteins that comprise the body. In addition to its absence in the list of twenty-one proteinogenic amino acids (the usual 20 plus selenocysteine), it may be inferred from the passage that hydroxyproline is created specifically for the increased stability of collagen (choice A is correct). Tyrosine, cysteine, and tryptophan are all proteinogenic amino acids and would be likely to be found in proteins distributed throughout the body. Any of these could be radiolabeled to aid in the measurement of non-procollagen protein (choices B, C, and D are wrong).
Which of the following statements about phosphofructokinase is true? It is non-competitively inhibited by ATP. It is non-competitively inhibited by AMP. It is competitively inhibited by pyruvate. A. I only Correct Answer B. II only C. I and II D. I and III Your Answer
A. In glycolysis, phosphofructokinase (PFK) catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate. The final product of glycolysis is pyruvate, and the goal of cellular respiration is to produce ATP. Cells undergo glycolysis if they lack energy and inhibit glycolysis if energy is abundant. Item I is true: ATP non-competitively inhibits PFK by binding to an allosteric site (choice B can be eliminated). Item II is false: AMP indicates an energy deficiency (i.e., a lack of ATP) and would not inhibit an enzyme in the pathway to make ATP! AMP actually activates PFK by binding to an allosteric site (choice C can be eliminated). Item III is false: pyruvate does not competitively inhibit PFK. Competitive inhibitors bind to an enzyme's active site and must be similar in structure to the enzyme's substrate. Pyruvate, a 3-carbon sugar, does not resemble fructose-6-phosphate, a 6-carbon phosphorylated sugar (choice D can be eliminated).
Which of the following is true? Viral genomes are made of either DNA or RNA, but never both. Viruses are composed of a maximum of three components: a capsid, a genome and an optional envelope. Viral genomes evolve, but change slowly over time due to their reliance on host cell machinery. A. I only Correct Answer B. I and II only C. II and III only D. I, II, and III Your Answer
A. Item I is true: viral genomes are either only RNA or only DNA (choice C can be eliminated) Item II is false: some viruses carry enzymes with them, for example, (-)RNA viruses carry RNA dep RNA pol in their capsids (choices B and D can be eliminated and choice A is correct). Note that Item III is false: viruses evolve relatively quickly due to their short generation time, high mutation rate and strong selective pressure.
If lactic acid radiolabeled with carbon-11 were injected intramuscularly in a patient, where would radioactive carbon most likely be detected? A. Expired breath Correct Answer B. Sweat C. Feces D. Hydroxyapatite
A. Lactic acid, which dissociates to become lactate at physiological pH, is converted to acetyl-CoA in the liver before rejoining cellular respiration and ultimately being released as carbon dioxide (choice A is correct). Any quantity of organic molecules excreted into the sweat and feces will be much smaller (choice B and C are wrong) and hydroxyapatite, the principal component of bone, does not contain carbon (choice D is wrong).
DNA "melting" is the process by which double-stranded DNA (dsDNA) is separated into single-stranded DNA (ssDNA). Which of the following accounts for an increase in the UV absorption of a sample of DNA undergoing DNA melting? The decreased capacity of ssDNA for H-bonding Structural changes altering conjugation across the aromatic DNA bases Greater functional group vibration at high temperature A. II only Correct Answer B. III only Your Answer C. II and III only D. I, II, and III
A. Process of elimination is the most effective method of determining the correct answer choice in this Roman numeral question. Item I is false: since the two strands of dsDNA are held together by networks of hydrogen bonds, once separated, the ssDNA will have many new, available sites for H-bonding (eliminate choice D). Item II is true: UV-Vis spectroscopy is used to measure changes in light absorption in highly conjugated systems, such as in aromatic compounds. The aromatic bases in dsDNA are tightly held in a coiled arrangement by H-bonds. When these interactions are removed in DNA melting, the chains can structurally relax. This allows changes in the conjugation of the bases, altering how much light is absorbed by a sample (eliminate choice B). Item III is false: changes in the vibrations of functional groups are monitored by infrared radiation, as UV radiation is far too energetic to induce such transitions (eliminate choice C).
During a humoral immune response, all of the following may occur EXCEPT: A. recognition of an epitope by a T killer cell. Correct Answer B. immunoglobulin binds an antigen. C. complement activation. Your Answer D. direct inactivation of an antigen by an antibody.
A. The humoral immune response is characterized by the presence of specific molecules known as antibodies or immunoglobulins. An epitope is the particular region or area on an antigen that is recognized by the variable region of an antibody (not a T cell; choice A would not occur, is not part of the humoral immune response, and is the correct answer choice). An antigen is the molecule that an immunoglobulin binds (choice B will occur and can be eliminated). The complement system can be activated by the presence of bound antibodies on a foreign cell (choice C will occur and can be eliminated). Antibodies alone have the ability to inactivate antigens by binding to and covering active sites on the antigens (choice D will occur and can be eliminated).
Another way to monitor urea degradation is by using phenolphthalein (pKa = 9.3), an indicator (In) that dissociates and changes color according to the following equation: HIn (colorless) <---> H+ + In- (magenta) Which of the following best explains why the solution turns magenta as urea degradation proceeds in the presence of phenolphthalein? A. Kb of NH3 > Ka of H2CO3 Correct Answer B. Ka of H2CO3 > Kb of NH3 Your Answer C. Ka of NH4+ > Kb of HCO3- D. Ka of NH3 < Kb of H2CO3
A. This is basically a stand-alone question, since the information in the question and the options in the answer choices alone are sufficient to answer the question. B and C are equivalent answer choices and can both be eliminated. Choice D confuses the constants and the chemical species. The Ka of NH3 is very small, as is the Kb of H2CO3, but neither is relevant here. Since the solution turns magenta as the reaction progresses, the basic form of the phenolphthalein indicator, In-, must be favored, indicating that the pH is above the pKa of phenolphthalein, 9.3. The solution contains both an acidic and a basic species, and in order for the overall solution pH to be basic, the Kb of the basic species must be greater than the Ka of the acidic species. This makes A the best answer.
At what incident angle (θi) does a ray have to first hit the collection face to end up traveling directly up the fiber (up the page in Figure 1)? A. 0° Correct Answer B. 45° Your Answer C. 60° D. 90°
A. With a cleaved angle of 45°, the light must be incident on the cleaved face at 45° to reflect at the same angle directly up the fiber. This means coming in directly from the right in Figure 1. We then need the light to come through the collection face parallel to the normal. This is the case in which there is no refraction: incident light perpendicular to the surface is transmitted perpendicular as well. This is an incident angle of 0° to the normal. Do not refer to the angle with respect to the surface and be mistaken with choice D.
The general form of kinetics of oxygen dissociation from oxyhemoglobin can be expressed as follows:
B. Because rate laws are expressed with the appropriate rate constant followed by the reactants which exert an effect on the order of the reaction, the only acceptable answer is the rate law shown for dissociation of Hb(O2)3 (choice B is correct). Possible rate law expressions for the association of oxygen with HbO2 to form Hb(O2)2 would need to include the concentration of oxygen in the equation due to its rate-determining role (choice A is wrong). A rate law for association of oxygen with oxyhemoglobin would include rate constant k' (choice C is wrong). Again, question stem states that oxygen exerts the only order-determining effect on association/dissociation rate laws - and, thus, the heme-O2 complex exerts no effect on rate and should not be included in the rate law (choice D is wrong).
Which of the following can result from ischemic changes due to the lack of circulated oxygenated blood seen in heart failure? A. Cardiac muscle contraction will be affected more than cardiac muscle relaxation since ATP and oxygen are required for myocardial contraction. B. Ischemic changes will result in a decreased amount of acetyl-CoA used by the Krebs cycle. Correct Answer C. Global ischemia, secondary to decreased perfusion of oxygenated blood, will result in alkalosis of the blood. D. Respiratory rate will increase as a result of low oxygen and carbon dioxide levels. Your Answer
B. Decreased oxygen will result in decreased aerobic respiration and therefore decreased activity of Krebs cycle and ETC (choice B is correct). It is important to recall that muscle relaxation is the phase of excitation-contraction coupling where ATP is used (choice A is wrong). Ischemia will result in acidosis from the increased production of acidic compounds (such as lactic acid) due to the inability to utilize aerobic respiratory pathways (choice C is wrong) and increased carbon dioxide levels (choice D is wrong).
An individual action potential in a model neuron results in 100 sodium ions crossing the cell membrane. Given that the sodium-potassium pump requires a single molecule of ATP per cycle, how many acetyl-CoA would be required to generate enough energy to extrude the new sodium in the cell via the pump? A. 1 B. 4 Correct Answer C. 5 Your Answer D. 50
B. Each acetyl-CoA generates 10 ATP equivalents (3 NADH = 7.5 ATP, 1 FADH2 = 1.5 ATP, and 1 GTP = 1 ATP) and the sodium-potassium pump removes three sodium from the cell per cycle at the expense of one ATP. A total of 34 cycles of the pump would be required to remove the 100 sodium from the cell and this would require 34 ATP. To ensure we have sufficient ATP, four acetyl-CoA are needed (choice B is correct).
When equilibrium is reached in the water/ethanol system at 90°C, what is the approximate mole fraction of ethanol in the gaseous phase? A. 0.15 B. 0.50 Correct Answer C. 0.60 Your Answer D. 0.95
B. Figure 2 is required to answer this question. The passage states that the upper line indicates the gaseous phase. At 90°C, the gaseous phase is approximately 50% water and 50% ethanol, making choice B the best answer.
What is the sine of the critical angle (sinθC) for total internal reflection off the cleaved face? A. 0.5 B. 0.8 Correct Answer C. 1.0 D. 1.25
B. Finding the critical angle begins by looking for the state where the refracted angle goes to 90°, or sin θ2 = 1 (stopping at this step makes choice C tempting). This means that, according to Snell's law, sin θC = n2 / n1. In this case this ratio is 1.33 / 1.67 = 4/5 = 0.8. Inverting the values gives choice D.
Complement activation
The complement system is a biochemical cascade of the innate immune system that helps clear pathogens from an organism. It is derived from many small blood plasma proteins that work together to disrupt the target cell's plasma membrane leading to cytolysis of the cell.
The virus herpes simplex I (HSV-I) normally lies dormant in infected individuals. Once activated, the virus enters the productive cycle, leaves the host cell via budding, and causes an outbreak of cold sores in the infected individual. What is the most likely reason that cold sores result? A. After host cell lysis, the host can immediately recognize the virus via antibodies and subsequently removes HSV-I infection from the body; cold sores are just a side effect of this action. B. After budding, the virus envelopes itself in the cell membrane of the host; this decreases host recognition of HSV-I, increases the length of time the virus can spread, and leads to a breakout of cold sores. Correct Answer C. After host cell lysis, the host cannot immediately recognize the virus itself and HSV-I goes on to infect other cells, causing a breakout of herpes cold sores around the mouth. D. After the virus is activated, it causes the host cell to release large amounts of hormones; this sudden regional hormone imbalance causes cold sores. Your Answer
B. HSV-I is able to lie dormant in host cells, so it must undergo the lysogenic cycle. The question stem also says that the virus enters the productive cycle when it is activated, meaning the new viral particles bud out of the host cell instead of lysing the host cell (choice A and C discuss host cell lysis and can be eliminated). When the virus buds out of the host cell, it acquires an envelope that is derived from the host cell plasma membrane. As a consequence, the host immune system can recognize the virus as "self" instead of "foreign," and therefore may not immediately attack it (choice B is correct). While a sudden hormone imbalance might trigger activation of HSV-I, cold sores are not caused by sudden regional hormone imbalance as a direct result of virus activation (choice D is wrong).
It has been shown that hydroxylation of proline in the presence of ascorbic acid dramatically increases the stability of the procollagen superstructure that comprises collagen. Which of the following likely contributes most to the added stability that results from hydroxylation? A. Increased hydrogen bonding Your Answer B. Stereoelectronic effects Correct Answer C. Van der Waals forces D. Steric effects
B. Hydroxylation of the proline functional group effectively produces an induced dipole in which the electronegative oxygen of the hydroxyl group makes the charge of the adjacent hydrogen and carbon atoms δ+; stereoelectronic effects in the form of "stacked" δ- and δ+ charges from the three inter-woven alpha helices in close proximity to one another creates a highly stable triple helix quaternary structure (answer choice B is correct). While it is possible that the hydroxyl groups may also form hydrogen bonds amongst each other, these forces would likely be less potent than stereoelectronic effects; in fact, evidence demonstrates that hydration has little effect on the structural stability of collagen (choice A is wrong). Van der Waals forces typically include both the attractive and repulsive forces between uncharged, non-bonded atoms; while in sum they can be quite strong, they are less likely to result in a stronger net stabilizing force than the stereoelectronic effect caused by the hydroxyl group (choice C is wrong). Steric effects typically entail the repulsive force caused by positioning atoms close together; such forces would be unlikely to stabilize the triple helix (choice D is wrong).
A. Overexpression of NALP1 leads to lower levels of IL-1β, which increase movement of T lymphocytes into tissues, leading to increased levels of T cell mediated melanocyte death. B. Overexpression of NALP1 leads to higher levels of IL-1β, which increase movement of T lymphocytes into tissues, leading to increased levels of T cell mediated melanocyte death. Correct Answer C. Underexpression of NALP1 leads to higher levels of IL-1β, which increase movement of T lymphocytes into tissues, leading to increased levels of T cell mediated melanocyte death. D. Underexpression of NALP1 leads to lower levels of IL-1β, which decrease movement of T lymphocytes into tissues, leading to decreased levels of T cell mediated melanocyte death. Your Answer
B. Table 1 and Experiment 2 indicate that the NALP1 mutation produces a protein of normal length, but in increased amounts (choices C and D can be eliminated). NALP1 overexpression could lead to increased melanocyte death via the NALP1-mediated pathway described in the passage; increased NALP1 would lead to increased active IL-1β (choice B is correct and choice A is wrong), which would enhance the movement of T lymphocytes into tissues. This could allow the T cells access to melanocytes, and T cells that recognize melanocyte-specific proteins could then kill these cells, leading to the symptoms of vitiligo (choice B is correct).
Glycogen is stored by the body via polymerization to form both α-1,6 and α-1,4 glycosidic bonds. Which one of the following statements would best provide evidence to support this structural feature? A. Glucose is highly water soluble, whereas glycogen does not appreciably dissolve in water. B. Glucose reacts with Benedict's reagent to form a red precipitate, whereas glycogen does not react. Correct Answer C. Both glucose and glycogen give O—H stretching bands in the infrared spectrum. D. The osmotic pressure of a dilute glucose solution is higher than that of a glycogen solution containing an equal mass of solute. Your Answer
B. The formation of glycosidic linkages between glucose monomers modifies the hemiacetal of glucose into an acetal. Benedict's reagent reacts with reducing sugars like glucose that contain hemiacetals to form a red precipitate, but not with non-reducing sugars that contain acetals, such as glycogen. Choice A is a true statement but can be eliminated because the difference in solubility doesn't speak to structure. Since both molecules show the same IR absorbance, no differentiating information is given to support the structures (eliminate choice C). Although choice D is also a true statement, it only supports that a polymer is created but does not reveal how the monomer units are connected.
Which of the following patients is most likely NOT presenting with celiac disease? A. A 41 year old male with a decreased blood clotting, abdominal pain, diarrhea, negative serological tests, and a cousin with celiac disease. Your Answer B. A 21 year old male with abdominal pain, elevated IgG, normal tTG-IgA, and no family history of celiac disease. Correct Answer C. A 16 year old female with a low body weight, iron deficiency anemia, negative serological tests, and a cousin with celiac disease. D. A 25 year old female with a low bone mineral density, abdominal pain, low IgA serum levels, negative serological tests, and a sister with celiac disease. TPR REVIEW 2 (B/B PASSAGE 5)
B. The passage states that celiac disease generally occurs in individuals with a strong family history of the disease and that onset can occur at any age. Therefore, ignore the age of the patient and focus on the other information. The individual in choice B has no family history of disease. Also, the passage says that elevated anti-tTG IgA levels are a more positive predictor of the disease; this patient has elevated IgG but normal anti-tTG IgA levels. It is not likely this patient has celiac disease (choice B is correct). All of the remaining patients have a family member with celiac disease and various symptoms of the disease. The individual in choice A has abnormal blood coagulation, abdominal pain, and diarrhea (the patient in choice A likely has the disease). The passage states that individuals with celiac disease also typically have malabsorption of nutrients, which leads to deficiencies in mineral levels. This could present as iron deficiency anemia or low bone density (the patients in choices C and D also likely have the disease).
Adenosine 5'-γ-thiotriphosphate is a common ATP analog in which one of the γ-phosphate oxygens is replaced by a sulfur atom. This molecule is hydrolyzed at a dramatically slower rate than ATP and functions as an inhibitor of ATP-dependent processes. Adenosine 5'-γ-thiotriphosphate would LEAST affect the function of: A. PI3K and Akt. B. EGFR and VEGFR. Your Answer C. p53 and CREB. Correct Answer D. PDK1 and Akt.
C. Based on the passage, PI3K, Akt and PDK1 are kinases and therefore require ATP as a substrate (the functions of choices A and D would be affected, so these choices can be eliminated). EGFR and VEGFR are described as receptor tyrosine kinases, and therefore also require ATP (the functions of choice B would be affected and can be eliminated). However, p53 is a pro-apoptotic protein and CREB is a transcription factor; while it is true that their activation depends on the activation of Akt (which requires ATP), there is no information to suggest that either of these would depend on ATP directly (the functions of choice C would be least affected, making this the correct answer choice).
In this cyclical process, two carbon dioxide molecules are combined with an acetyl-CoA to ultimately generate a new acetyl-CoA. In cellular respiration, acetyl-CoA also serves as an intermediate. Which of the following best characterizes the chemical process acetyl-CoA's precursor undergoes during cellular respiration? A. Isomerization B. Carboxylation Your Answer C. Oxidation Correct Answer D. Reduction
C. Acetyl-CoA is produced by the pyruvate dehydrogenase complex during cellular respiration. This process involves the conversion of pyruvate (the precursor) into acetyl-CoA with the liberation of a carbon dioxide molecule in the process. At the same time, one NAD+ is converted to NADH. Without needing to know the structures of pyruvate or acetyl-CoA, the conversion of NAD+ to NADH is a reduction reaction (increasing number of bonds to hydrogen) which must mean that the conversion of pyruvate to acetyl-CoA is an oxidation (choice D is wrong and C is correct). An isomerization reaction would involve breaking and reforming bonds but no change in molecular formula (choice A is wrong) and removal of a carbon dioxide from pyruvate is a decarboxylation (choice B is wrong).
How many products are expected when the decapeptide VRVPVSQLQM is digested by an aminodipeptidase specific for N-terminal valine? A. Two products Your Answer B. Three products C. Four products Correct Answer D. Ten products
C. As shown in Figure 1 of the passage, an aminodipeptidase, such as DPP-4, cleaves a dipeptide from the N-terminal of a peptide. In order to correctly digest the decapeptide VRVPVSQLQM, a dipeptide will be cleaved from the N-terminal with the condition that this only takes place if valine is present at the N-terminal, as given by the question. Thus, digestion of VRVPVSQLQM proceeds to give VR + VPVSQLQM. The remaining octapeptide bears valine so digestion will continue until valine is no longer present at the N-terminal, as shown in the outline below: VRVPVSQLQM à VR + VPVSQLQM à VP + VSQLQM à VS + QLQM By the end of the digestion, the decapeptide VRVPVSQLQM is digested into the following four products: VR + VP + VS + QLQM (choice C is correct; choices A and B indicate too few products). Another protease is needed to cleave the remaining peptide bonds and so it is not possible to obtain complete hydrolysis of the decapeptide into its ten constituent amino acids using an aminodipeptidase (eliminate choice D) as it is not possible).
Which of the following correctly describes potential treatments used in heart failure? A. Patients can be treated with intravenous fluids to increase the venous return and cardiac output. B. An angiotensin receptor blocker (ARB) can be given to decrease the effect of angiotensin I in congestive heart failure. C. Adrenergic receptor blockers, such as beta blockers, can be given to decrease cardiac workload and the effects of sympathetic tone. Correct Answer D. A diuretic, such as one that blocks the reabsorption of sodium in the descending Loop of Henle, can be given to provide relief from congestive heart failure. Your Answer
C. Blocking the adrenergic receptor can decrease cardiac demand and prevent decompensation (further deterioration) from increased sympathetic tone in heart failure (choice C is correct). Giving intravenous fluid will only worsen the congestion due to fluid retention (choice A is wrong). Angiotensin I is the inactive precursor of angiotensin II and must be converted by ACE to have any effect in heart failure (choice B is wrong). It is important to recall that the descending loop of Henle is impermeable to sodium and only allows water reabsorption (choice D is wrong).
Using basic geometry and properties of vectors, the student determines that the balls in trials 3 and 4 have roughly the same final velocity component in the direction opposite to the electric field (the "vertical" direction in Figure 1). What best explains this? A. The balls starting at points A and B have the same negative charge. Your Answer B. The balls travel the same total distance under the same acceleration. C. The final velocity in the "vertical" direction is the same because the balls underwent the same acceleration over the same duration. Correct Answer D. The final velocity in the "vertical" direction is the same because the ball in trial three underwent half the acceleration of the ball in trial 2 but did so over twice the duration.
C. It's true that the balls have the same charge, but that's not enough to explain the same final velocity component opposite to E (or else trial 5 would also have the same final speed as trial 4). This eliminates choice A. Choice B is simply false: a ball leaving point A travels further to the right edge of the frame than a ball leave point B. Choice C is true: balls with the same charge and same mass undergo the same acceleration (eliminating Choice D), and the duration over which they undergo this acceleration is determined by t = x / vx, which will be the same for trials 3 and 4 (the ball in trial 3 has twice the horizontal displacement as the ball in trial 4 but with twice the horizontal velocity).
Which of the following tissue layers contain blood vessels? Epidermis Dermis Hypodermis A. I and II only B. II only Your Answer C. II and III only Correct Answer D. I, II, and III only
C. Item I is false: the epidermis is avascular (does not have blood vessels, choices A and D can be eliminated). Cells of the epidermis receive oxygen and nutrients from the vessels in the dermis via diffusion. Note that both remaining answer choices include Item II. Item II is true: the dermis does contain blood vessels. Item III is true: the blood vessels of the skin run through the hypodermis and into the dermis (choice B can be eliminated and choice C is correct).
Multiple sclerosis (MS) is an autoimmune disease that results in demyelination of central nervous system axons. Which of the following could change as a result of this condition? Perception of sensory stimuli Temporal summation in a postsynaptic neuron The strength of an action potential in a demyelinated axon A. I only Your Answer B. II only C. I and II only Correct Answer D. I, II, and III
C. Items I and II are true: Demyelination of an axon can result in slowed or lost conduction of action potentials, which could affect all types of stimuli perceived by the nervous system (choice B can be eliminated). Specifically, this affects the timing of neurotransmitter release by the neuron, which then changes the frequency of EPSPs or IPSPs in the postsynaptic cell (choice A can be eliminated). Item III is false: Action potentials are "all-or-none" phenomena, and their magnitude does not change (choice C is correct and choice D is wrong).
In a state of starvation, the body utilizes amino acids for gluconeogenesis and excretes the nitrogen byproduct, creating a negative nitrogen balance. Thus, the level of mRNA expression for CPSI and OTC during starvation is most likely to: A. decrease due to the lack of amino acids absorbed from the diet and decreased demand for these enzymes. Your Answer B. remain about the same because expression of these enzymes is only triggered by a relative increase in ammonia. C. remain about the same because increased enzymatic activity is achieved through reduced breakdown of the enzymes. Correct Answer D. increase due to increased demand for the activity of these enzymes in a catabolic state.
C. Negative nitrogen balance from the catabolism of muscle and other protein-rich tissues implies that increased activity of CPSI and OTC is needed to avoid hyperammonemia. However, because amino acids are being diverted to gluconeogenesis during starvation, the more likely means for boosting enzymatic activity is inhibiting breakdown rather than increase transcription and translation (in other words, amino acids are being used for food, instead of for protein synthesis, choice C is correct and choice D is wrong). While it is true that there will be a lack of absorption of amino acids in a state of starvation, the breakdown of other proteins in the body and negative nitrogen balance actually increases demand for the action of these enzymes, so transcription would not decrease (choice A is wrong). Though it is true that higher blood NH3 levels typically coincide with increased urea cycle enzyme activity, there is no indication that blood ammonia levels would be increased in starvation relative to a fed state (choice B is wrong).
Which of the following is true regarding the hydroxyl (-OH) group bridging the two nickel centers in the active site of urease? A. The pKa of the bridging hydroxyl is roughly the same as the pKa of methanol. B. The pKa of the bridging hydroxyl is higher than the pKa of methanol. Your Answer C. The pKa of the bridging hydroxyl is lower than the pKa of methanol. Correct Answer D. The relationship between the pKa of methanol and of the bridging hydroxyl cannot be determined with the given information.
C. The bridging hydroxyl group has three bonds, one to each Ni and one to the protic hydrogen. This means that the oxygen has a formal positive charge. This charge serves to polarize the O—H bond more than it is in a molecule like methanol, where there is no such formal charge, making the proton even more acidic. Likewise, the conjugate base of the bridging hydroxyl has no charge, and is therefore more stable than the conjugate base of methanol (methoxide). Since low pKa indicates strong acidity, the bridging hydroxyl will have a lower pKa than methanol.
A negatively charged ball travels from Point A to Point P to Point C. Which of the following is true? Potential energy of the ball increases from Point A to Point P, then decreases from Point P to Point C Total change in potential energy is 0 Total work done by the electric field is 0 A. I only B. II only Your Answer C. II and III only Correct Answer D. I, II, and III
C. The electric field lines point to the bottom of the frame and a negative charge moving in a direction opposite the direction of the field lines will be moving with the field. This means that when the ball moves up to Point P, the electric field will be doing positive work and the ball will be losing potential energy. This is the opposite of what Item I states, so Item I is false, eliminating choices A and D. The total change in potential energy depends on the initial and final potential values. Since the ball starts at Point A and ends on Point C, the total change in potential is zero; both points are on the same equipotential line (remember equipotential lines are perpendicular to the electric field lines, so in this case the equipotential lines run parallel to the bottom of the frame). Since V = 0, ΔPE = qV = 0, so Item II is true, eliminating choice A. Because -ΔPE = Wdone by field = 0, Item III is true, eliminating choices A and B. The correct answer is choice C.
If the n = 4 to n = 3 transition of an atom emits yellow light, which of the following transitions in this same atom could emit red light? A. The n = 4 to n = 2 transition B. The n = 3 to n = 2 transition Your Answer C. The n = 5 to n = 4 transition Correct Answer D. The n = 1 to n = 2 transition
C. This question requires an understanding of the relative energies of visible light in the electromagnetic spectrum. Red light is lower frequency, longer wavelength, and lower energy than yellow light. Thus we are looking for a transition that will emit less energy than the n = 4 to n = 3 transition. D can be eliminated immediately, as promoting an electron to a higher level absorbs light rather than emitting it. Intuitively, n = 4 to n = 2 must release more energy than n = 4 to n = 3, so choice A is wrong. To choose between options B and C, it is necessary to recall that the gap between adjacent energy levels decreases with increasing distance from the nucleus. Thus the n = 5 to n = 4 is indeed a lower energy transition than the n = 4 to n = 3 transition.
Hill coefficient
Coefficient greater than 1 means the enzyme exhibits positive cooperativety If the coefficient is approximately equal to 1, then it does not exhibit cooperativety If less than 1 ---> negative cooperativety
Additional experiments were conduced on the genomic DNA isolated from Langerhans cells from the 10 vitiligo patients in the passage. Researchers found that each patient had the same genomic mutation. Given the results in Table 1 and Experiment 2, which of the following could be true of this mutation? The mutation is a nonsense mutation in the NALP1 gene. The mutation is in the promoter region of the NALP1 gene. The mutation resulting in the NALP1 phenotype could be in the gene for another protein. A. II only B. III only Your Answer C. I and III only D. II and III only Correct Answer
D. According to the results in Table 1 and Experiment 2, the vitiligo patients have an NALP1 protein that is the normal length, but in increased amounts. Thus, the NALP1 mutation likely affects the regulation of NALP1 expression, rather than the structure of the NALP1 protein itself. Item I is false: a nonsense mutation introduces a premature stop codon and would result in a shortened NALP1 protein (choice C can be eliminated). Item II is true: a mutation in the promoter region for the NALP1 gene could result in increased gene expression. For example, the mutant promoter could attract RNA polymerase II with greater ease, leading to increased NALP1 expression (choice B can be eliminated). Item III is true: other proteins, such as transcription factors or repressors, can affect gene expression. A mutation in a protein that regulates NALP1 transcription could result in overexpression of the NALP1 protein (choice A can be eliminated and choice D is correct).
The Ktrans/cis of the unsubstituted tertiary amide model in benzene is likely closest to which of the following values? A. 1.9 B. 4.2 C. 7.2 Your Answer D. 12.1 Correct Answer
D. Benzene has no dipole moment. Therefore, with the established trend of large Ktrans/cis in nonpolar solvents, one would expect a larger value than any of those obtained in the experiments in Table 1. This value is 12.1 (choice D).
When dissolved in water, Cu2+ often forms the complex [Cu(OH2)6]2+. Which of the following is NOT true regarding this complex? A. The Cu2+ ion is weakly bound to the oxygen atom in the surrounding water molecules. B. The oxidation state of the copper is +2. Your Answer C. The oxygen in the water acts as a Lewis base. D. The hydrogen in the water acts as a Lewis acid. Correct Answer
D. In this complex, the cationic Cu2+ is weakly coordinated to water, though dative (coordinate covalent) interactions with lone pairs on the oxygen. Therefore, choice A is eliminated. The water molecules are neutral so if the overall charge of the complex is +2, then the charge on the copper must also be +2 and choice B is eliminated. The oxygen of water does indeed donate a lone pair of its electrons to copper, so it acts as the Lewis base and copper is the Lewis acid. This eliminates choice C. Choice D is the only one that does not accurately describe the complex. The hydrogen atoms of the water are not involved in the bonding with copper.
A patient presents with coronary artery disease (CAD) in which plaque has accumulated in the vessels, reducing but not blocking blood flow to cardiac muscle. What symptoms would be expected in this patient? Increased heart rate Incidences of chest pain Decreased oxygen supply to heart muscle A. I only B. II only C. I and III only Your Answer D. II and III only Correct Answer
D. Item I is false: though plaque build-up in the coronary arteries is obstructive to those vessels, this does not have a direct impact on heart rate. A person with CAD could still have a normal pulse (choices A and C can be eliminated). Since both of the remaining answer choices include Item II, Item II must be true: chest pain is a common symptom of blocked coronary arteries, caused by a lack of oxygen delivery to the heart muscle. Item III is true: the supply of oxygenated blood would be limited (choice D is correct and choice B can be eliminated).
Which of the following choices most accurately characterizes the inhibitory effect of PDMP on NAG? A. Competitive B. Non-competitive C. Uncompetitive Your Answer D. Mixed-type Correct Answer
D. Since Vmax decreases with the addition of inhibitor, it cannot be competitive inhibition (eliminate choice A). Since Km increases, neither non-competitive (no change in Km) nor uncompetitive inhibition (decrease in Km) is taking place (eliminate choices B and C). The Lineweaver-Burk plot shown in Figure 2 indicates mixed inhibition, (choice D is correct) as both the Vmax and Km change with addition of inhibitor (as seen by the changes in x- and y- axis).
When sphingomyelin is hydrolyzed in the presence of a strong acid, which of the following is/are the product(s)? Sphingosine Choline Fatty acid A. I only B. II only C. I and III only Your Answer D. I, II, and III Correct Answer
D. Strongly acidic hydrolysis conditions result in cleavage of both the amide and the phosphate ester.
Which of the following is true regarding the function of the right and left ventricles? A. The right ventricle and left ventricle produce equal systolic pressures, but have unequal ejection fractions. B. The right ventricle and left ventricle produce both equal systolic pressures and equal ejection fractions. C. The right ventricle and left ventricle produce both unequal systolic pressures and equal ejection fractions. Your Answer D. The right ventricle and left ventricle produce unequal systolic pressures, but have equal ejection fractions. Correct Answer
D. The 2x2 method can be used here. This method allows you to eliminate answer choices based on identifying that two answer choices have a similar structure with only a key word or two in difference. For example, looking at choices A and B, both choices indicate that both the left and right ventricles produce equal systolic pressures. We know that this cannot be true because the right ventricle only supplies the pulmonary circulation and would not require, nor have the ability, to produce the pressure needed to supply the systemic circulation, as the left ventricle does (choices A and B can be eliminated). Although the right and left ventricles produce unequal pressures, they do have the same stroke volume and therefore equal ejection fractions (choice A is wrong and choice D is correct).
A parallel-plate capacitor (with a vacuum in between the plates) is connected to a battery. In Step 1, the distance between the plates is increased while the battery is still attached. In Step 2, the battery is disconnected and a dielectric is placed in between the plates. Which of the following is true about the change of potential energy in each of the steps? A. ΔPE1 > 0 and ΔPE2 > 0 Your Answer B. ΔPE1 > 0 and ΔPE2 < 0 C. ΔPE1 < 0 and ΔPE2 > 0 D. ΔPE1 < 0 and ΔPE2 < 0 Correct Answer
D. The equation for capacitance is C = κε0A / d, where κ is the dielectric constant (κ > 1), ε0 is a constant, A is the area of the plates and d is the separation between plates. In Step 1, d increases, therefore C decreases. In Step 2, κ increases, therefore C increases. The potential energy stored in a capacitor can be written as (1/2)CV2 or Q2 / 2C. In Step 1, the battery remains attached which means that V remains constant, so use the equation for PE with the V term. In that case, PE ∝ C, so decreasing C means the potential energy must therefore decrease. This eliminates choices A and B. In Step 2, the battery is disconnected, which means that Q remains constant, so use the equation for PE with the Q term. In that case, PE ∝ 1 / C, so increasing C means the potential energy must therefore decrease. The correct answer is choice D.
What is the likelihood that a daughter of an affected father with one copy of the huntingtin mutation (comprising 52 copies of the CAG repeat) will exhibit symptoms of Huntington's disease? A. 0%, but she will be a carrier of the mutation B. 0%, and she will not be a carrier of the mutation C. 100% Your Answer D. 50% Correct Answer
D. The passage states that the huntingtin mutation is on chromosome 4 and is therefore autosomal. The passage also states that the trait exhibits dominant inheritance and that penetrance is 100% once the number of CAG repeats surpasses 36. An affected father with one mutant allele has a 50% chance of passing this allele on to his children. All of his offspring that inherit the mutant allele will be affected (choice D is correct and choices A, B, and C are wrong).
The fixation of carbon in order to generate acetyl-CoA involves which of the following processes? A. GTP production B. Release of bicarbonate Your Answer C. NADPH generation D. ATP hydrolysis Correct Answer
D. The process of carbon fixation requires a significant investment of energy to form a higher energy product (choice D is correct). This principle is critical to understanding metabolism: higher energy molecules (e.g., carbohydrates) are broken down into lower energy molecules (e.g., carbon dioxide) to generate ATP. During carbon fixation, this process is effectively reversed, meaning that ATP would be consumed. It would therefore be unlikely that ATP (or ATP equivalents) would be generated (choice A is wrong). NADPH is produced via the pentose phosphate pathway and is consumed, not generated, during anabolic processes (choice C is wrong). There is no reason to assume bicarbonate (HCO3-) would be generated or released (choice B is wrong).
Which of the following provides the most likely explanation for the widely different types of symptoms observed in Gaucher's syndrome? A. The accumulation of GlcCer in lysosomes eventually results in overly full cells that undergo apoptosis. Your Answer B. Deficiency of β-galactosidase results in a deficiency of a protein needed for normal cell functioning. C. Precursors of GlcCer accumulate in the lysosomes of the cell resulting in concentrations which are cytotoxic. D. Ceramide is ubiquitously expressed throughout the body and across organ systems. Correct Answer
D. The question asks why Gaucher disease results in symptoms that affect nearly every organ system of the body. The passage indicates that ceramide is a vital ingredient in the healthy cell membrane; without this vital ingredient, cell membranes of tissues across all organ systems are deprived of a vital component and fail to form normal, functioning tissues (choice D is correct). While it is true that accumulation of GlcCer eventually leads to cell death, this explanation fails to explain the wide variety of symptoms observed in Gaucher disease (eliminate choice A). The enzyme deficient in Gaucher's disease is β-glucocerebrosidase, not β-galactosidase (eliminate choice B). While it may be true that precursors of GlcCer may accumulate in the cells of Gaucher's disease patients, the passage makes no mention of this potential etiology nor is it the chief pathogenic mechanism for this disease (eliminate choice C).
Most sugars exist in equilibrium between a cyclized form and a straight chain structure. If Compound 4 were to cyclize, what type of ring would be expected to form? A. A pyranose ring B. A furanose ring C. A β-lactone ring Your Answer D. Compound 4 won't cyclize due to the presence of the phosphate group. Correct Answer
D. When a sugar cyclizes, an OH group on the last or the penultimate carbon in the chain performs a nucleophilic attack on the carbonyl carbon, forming a hemiacetal. Lactones are cyclic esters and therefore the wrong functional group (eliminate choice C). Six-membered pyranose rings or five-membered furanose rings are very common because these ring sizes have minimal strain, but in both cases one of the atoms of the ring is an O from the attacking OH group. In order for the intramolecular cyclization to occur for Compound 4, the OH group on C-4 would have to attack the ketone to yield a four-membered ring, composed of C-2, C-3, C-4, and the O on C-4. This smaller ring would suffer from high ring strain due to less than optimum bond angles, and is very unlikely to form. Choice D is therefore the best answer. In the absence of the phosphate group, the OH group on C-5 would be capable of forming an unstrained furanose ring.
AA that will likely be found in the residue undergoing a deamidation reaction
De AMIDE It will either be asparagine or glutamine, as these are the only two amino acids with an amide in their side chain *(Deamination is the removal of an amine and is the process that all amino acids undergo when they are broken down. However, the only AA's with an amine group in their SIDE CHAIN are lysine and arginine)
ELISA
ELISA (enzyme-linked immunosorbent assay) is a plate-based assay technique designed for detecting and quantifying substances such as peptides, proteins, antibodies and hormones. Other names, such as enzyme immunoassay (EIA), are also used to describe the same technology.
Limbic system
Emotions and memory
Autophosphorylation? Ex. "GSK and PKA have been shown to autophosphorylate"
First, GSK and PKA are both protein kinases which means that they add a phosphate group from ATP (In contrast to phosphorylases which add phosphate groups from inorganic phosphate in the cytosol). Basically, autophosphorylation is when the kinase enzyme phosphorylates one of its own serine, threonine or tyrosine residues (read below for more detail). **** Autophosphorylation is a type of post-translational modification of proteins. It is generally defined as the phosphorylation of the kinase by itself. In eukaryotes, this process occurs by the addition of a phosphate group to serine, threonine or tyrosine residues within protein kinases, normally to regulate the catalytic activity.[3][4] Autophosphorylation may occur when a kinases' own active site catalyzes the phosphorylation reaction (cis autophosphorylation), or when another kinase of the same type provides the active site that carries out the chemistry (trans autophosphorylation). The latter often occurs when kinase molecules dimerize. In general, the phosphate groups introduced are gamma phosphates from nucleoside triphosphates, most commonly ATP.
Humoral immunity
Humoral immunity, also called antibody-mediated immunity, is the aspect of immunity that is mediated by macromolecules (as opposed to cells) found in extracellular fluids such as secreted antibodies, complement proteins, and certain antimicrobial peptides
Ischemia
Ischemia is a restriction in blood supply to tissues, causing a shortage of oxygen and glucose needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems with blood vessels, with resultant damage to or dysfunction of tissue.
Kinase vs. phosphorylase
Kinase = add's atp Phosphorylase = add's inorganic phosphate from cytosol
How to remember nucleotide base structures
Pure As Gold --- Purines (2 ring) = Adenine and Guanine CUT ---- Pyrimidines (1 ring) = Cytosine, Uracil (RNA) and Thymine (DNA) IF IT HAS 0 CARBONYLS = Adenine IF IT HAS 1 CARBONYL = Guanine or Cytosine (cytosine will have only one ring, while guanine will have two) IF IT HAS 2 CARBONYLS = Uracil or Thymine (thymine is methylated while uracil is not) *********************************** Adenine is the only base with NO CARBONYLS while Guanine has one carbonyl Cytosine is very similar to Adenine (they are both the first in their respective mnemonics) Uracil and Thymine are very similar to Guanine The difference between Uracil and Thymine is that Thymine is a methylated version of Uracil The pyrimidines have X carbonyls, where X = the number of carbonyls from their "similar purine" + 1. So, because cytosine is "similar" to adenine, cytosine will have 1 (0+1) carbonyls. Uracil and thymine on the other hand, will have 2 (1 + 1) carbonyls.
If a strand of protein replicating a protein receptor is synthesized in the lab could it have therapeutic benefit
No. Because it does not exist in vivo. It is not like an enzyme inhibitor that can be taken orally. Specifically, there is not an easy way to alter gene expression at the cellular level, which would be required for the sequence of amino acids to be present in your cell membranes *** In order to assess therapeutic benefits, more studies would need to be performed. Primarily in regards to the native receptor that the synthesized strand is modeled after
FSH
Peptide hormone known to activate FSH G-protein coupled receptors (FSHRs) on ovarian cells. FSHRs have also been found on osteoclasts.
How can different forms of the same protein be expressed in cells?
They are isoforms of eachother. Different protein isoforms are synthesized from the same gene through alternative splicing. Different combinations of exons can produce different protein isoforms mRNA TRANSCRIPTS WITH DIFFERENT COMBINATIONS OF EXONS
To determine if a molecule acts as an inhibitor, what conditions should gel electrophoresis be run under for the experimental and control
They should both be run under native page To assess whether the molecule inhibits the enzyme, it is essential to analyze the given interaction when they are both in their native state. Reducing conditions will break apart di-sulfide bonds. Denaturing conditions will disrupt interactions between monomer units (it will disrupt the quaternary structure). Both of these should be avoided
Holoenzyme vs coenzyme vs cofactor vs cosubstrate vs prosthetic group
cofactor = mineral that speeds up rate of rxn coenzyme = specific type of cofactor that is an organic molecule prosthetic group = specific type of cofactor that binds tightly to protein or enzyme holoenzyme = enzyme with particular cofactors and/or coenzymes attached -- enzyme that is ready to catalyze its given reaction cosubstrate = loosely bound cofactor that is regenerated in the reaction apoenzyme = inactive enzyme / enzyme without given cofactors/coenzymes attached