B/B Review Flashcards
When the heart muscle contracts, pushing blood out
systole
Enzymes that catalyze the breakdown of proteins into smaller polypeptides or single amino acids
protease
ssDNA is held together by what type of bond?
phosphodiester bonds
How is ssDNA denatured?
When the nucleases break apart their phosphodiester bonds that hold the individual nucleotides
note: Slight increases in heat would NOT break apart these bonds. They would for hydrogen bonds in dsDNA though
DNA renaturation involves the formation of base pairs. This is an [exothermic/endothermic] process
exothermic process
heat is released
forming bonds is ALWAYS exothermic
Bond breaking is an [endothermic/exothermic] process
endothermic process
because it REQUIRES energy
adds nucleotides to growing DNA chains and participates in DNA replication
DNA polymerase
True or False
Proteins lose 3D shape when they’re denatured, but not their amino acid (primary) formation
True
this breaks the hydrogen bonds
myelinating cells of the central nervous system (CNS)
oligondendrocyte
Signals from neurons that have myelin degredation would disspiate [faster/slower] than healthy neurons
faster
genetic regulatory system found in bacteria and their viruses in which genes coding for functionally related proteins are clustered along the DNA
operon
a region of DNA upstream of a gene where relevant proteins (such as RNA polymerase and transcription factors) bind to initiate transcription of that gene
promoter
a gene involved in controlling the expression of one or more other genes
regulator gene
genes that code for proteins and RNAs except regulatory factors
structural genes
a series of three genes in bacteria that produce the necessary enzymes to obtain energy from lactose.
lac operon
organic compounds without a benzene ring
aliphatic compounds
catalyse the transfer of phosphate groups from ATP molecules to a specific substate.
kinase
catalyze the decomposition of ATP into ADP and a free phosphate ion.
ATPase
use water molecules to dephosphorylate a substrate
phosphatase
Presence of the Effector
enables transcription
inducible regulation
Presence of the Effector
blocks transcription
repressible regulation
The Repressor binds
to the Operator
to block transcription
Negative Regulation
The Activator binds
to the Operator
to enable transcription
Positive Regulation
True or False
Cellular components like lymphocytes, antibodies, proteins, etc are a lot larger than ions and glucose. Unless otherwise stated, don’t assume they can diffuse through membranes
true
True or false
a single mutation event is almost always more likely than multiple events
True
having only one sex chromosome
monosomy
Monosomy’s are usually unviable; they tend to result in a plethora of health problems that cause infantile death
True or False
Multiple mutation events are just as likely as a single mutation event
False. A single mutation event is almost always more likely than multiple events
Paternal nondisjunction conferring two copies of a gene would result in what genetic condition?
trisomy
two copies from the father, and one from the mother
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
nondisjunction
another name for amino acids.
Monomeric proteins
the fatty acid chains of triglycerides contain ____ fatty acids
the fatty acid chains of triglycerides contain 18 fatty acids
glycogen breaksdown into glucose-1-phosphate and glucose
glycogenolysis
An increase in glycogenolysis would lead to a [increase/decrease] in glycogen levels
An increase in glycogenolysis would lead to a decrease in glycogen levels
used as an energy source during the elongation and translocation steps of translation
GTP
increases the MW of a molecule (because it is becoming a macromolecule of repeating segments)
oligomerization
First step in gene expression. It involves copying a gene’s DNA sequence to make an RNA molecule.
mRNA is “decoded” to build a protein (or a chunk/subunit of a protein) that contains a specific series of amino acids.
translation
in this stage of translation, the ribosome gets together with the mRNA and the first tRNA so translation can begin.
initiation
in this stage of translation, amino acids are brought to the ribosome by tRNAs and linked together to form a chain.
elongation
in the stage of translation, the finished polypeptide is released to go and do its job in the cell.
termination
small organic molecules that allow enzymes to be effective
coenzyme
generally non-protein inorganic molecules that allow enzymes to be effective
cofactor
Elements that can insert and remove themselves from the genome. In prokaryotes, they can act as a “stress response: system, allowing for rapid inactivation of genes in response to alteration in environmental conditions.
transposons
Cell-surface components or appendages of bacteria that facilitate adhesion or adherence to other cells or to surfaces, usually in the host they are infecting or living in. ____ are a type of virulence factor.
surface adhesins
an activator protein is unable to bind to the gene and no transcription takes place until an inducer binds to the activator protein
positive inducible operons
allows filtration (movement from the circulation into the nephron tubule) of small molecules while blocking the filtration of plasma proteins)
glomerulus
Name the kidney structure
reabsorption of water, which serves to concentrate the filtrate.
descending loop of Henle
Capillaries that supply nutrients to the nephron. Not part of filtration process itself as they are not apart of the nephron
vasa recta
True or False
Salt is PASSIVELY filtered into Bowman’s capsule at the glomerulus and does not require active sectretion to become a part of the filtrate.
True
Amount of solute per kg of solution. requires reabsoprtion and secretion to be regulated and controlled by the kidney.
blood osmolality
How is sugar filtered through the glomerulus and proximal convuluted tubule?
Sugar is passively filtered at the glomerulus and then ACTIVELY reabsorbed in proximal convulated tubule
Occur when the binding properties of a macromolecule change as a consequence of a second. ligand binding to the macromolecule and altering its affinity towards the first, or primary, ligand. In Hb, the binding of oxygen to one of the subunits is affected by its interactions with the other subunit
allosteric effects
If less water is reabsorbed through the loop of Henle, [more/less] water is eventually excreted in urine
If less water is reabsorbed through the loop of Henle, more water is eventually excreted in urine
One of many causes of this could be glucose being trapped in the nephron isntead of being reabsorbed
The partial pressure of oxygen in the alveoli must be [higher/lower] than the partial pressure of oxygen in the capillaries. This is b/c oxygen difussed from the aveoli to the alveolar capillaries
The partial pressure of oxygen in the alveoli must be higher than the partial pressure of oxygen in the capillaries.
begins when the morula develops a fluid-filled cavity, which by the fourth day of development becomes a hollow sphere of cells called the blastula
blastulation
the avg molecular weight of an amino acid is…
110daltons
How do you figure out how many amino acids are in a protein given the protein’s molecular weight?
Divide the protein’s weight by the avg weight of an amino acid (110) e.x a protein whose weight is 15 kDa / 110 daltons = 140 aa’s in the protein
**β-adrenergic receptors are predominant postsynaptic receptors in which division of the nervous system?
The sympathetic nervous system
remember, adrenaline = epinephrine, a key neurotransmitter/hormone in the sympathetic nervous system
The concentration of ligand at which half the receptors are occupied
Kd
Kd for receptors and their ligands is analogous to Km in enzyme-substrate interactions
A competitive receptor antagonist (inhibitor) is something that….
Bind to the same sites on the receptor as a ligand and (unlie non-competitive and other allosteric inhibitors) can be displaced with suffiecient quantaties of ligand
Enzymes decrease the activation energy of a reaction by stabilizing the ____
transition state
The balance point of catalysis. The state corresponding to the highest potential energy along this reaction coordinate
Transition state
Acidic amino acids have ____ charges at physiological pH
Negative
Acidic amino acids are those amino acids that have a carboxylic acid group on their side chains at neutral pH, resulting in acidic properties in the molecule. The aqueous solution of these amino acids at physiological pH results in the ionization of the three functional groups present on the amino acids. This results in the** overall charge of -1.**
The attractive or repulsive interaction between objects having electric charges
electrostatic interactions
aka Van der Waals
A protein that is 118 amino acids long has how many peptide bonds?
117
There is always one less peptide bond than there is amino acids
Process where a metabolite produced early in a pathway activates an enzyme that catalyze a reaction further down the pathway.
feed-forward activation/stimulation
Ex: pyruvate kinase being stimulated by fructose-1,6-biphosphate in glycolysis
True or False
Hyperinflated lungs occur when air gets trapped in the lungs and causes them to overinflate. Hyperinflated lungs can be caused by blockages in the air passages or by air sacs that are less elastic, which interferes with the expulsion of air from the lungs.
True
The diaphram has ____ muscle
skeletal
The effector neurotransmitter of the diaphram is ….
acetylcholine
when you think muscle contraction NT, think acth!
Organisms that undergo a fair amount of cellular activity must use a fair amount of ATP. What cellular process would best support this ATP production?
oxidative phosphorylation
whenever a MCAT question asks about an organism that is complex enough to have a good amount of cellular actrivity, think significant ATP levels, and think oxidative phosphorylation
Produces essential precursor ribose-5-phosphate for nucleotide synthesis, necessary for both DNA replication and RNA transcription
pentose phosphate pathway
cAMP mediated protein kinase activity is increased when ____ are bound and activated
G protein coupled receptors
Largest family of membrane proteins and mediate most cellular responses to hormones and neurotransmitters, as well as being responsible for vision, olfaction and taste.
GPCRs
The most destructive mutations are ….
frameshift mutations
move stuff around
mutation causes the substitution of one amino acid for another
missense mutation
does not always cause mutations, is possible though
Involves a single alteration to the DNA base pair that results in the production of a stop codon, thereby terminating protein synthesis prematurely. Results in a shortened protein that may function, but also may not.
nonsense mutation
Three-nucleotide deletion in the gene would result in the loss of one amino acid. Is this as devastating as a framseshift mutation?
No. A 3-nucleotide deletion could affect the three-dimensional structure of the resulting protein, but this is not as devastating an effect as is a reading frame shift
Do intermediates count as products in pathways?
Yes
True or False
If something in a reaction is reduced, then another thing is oxidized
True, this is why they are called reduction-oxidation reactions
True or False
Mitosis involves double-stranded DNA breaks during recombination
False. MEIOSIS features recombination and crossing over, not mitosis
What’s the mnenonic for southern, western, and northern blots?
uses fluorescent DNA probes to bind to chromosomes and could detect a translocation by detecting a gene on an unexpected chromosome
fluorescent in situ hybridization (FISH)
generally short peptides that act as a signal fragment that mediates the transport of proteins from the cytoplasm into the nucleus.
nuclear localization signal
Rroteins involved in the process of converting, DNA into RNA; bind DNAs and must have DNA binding motifs
transcription factors
What is the final acceptor in the ETC
oxygen
When the electron transport chain is not available to make energy (ATP) the cells will rely solely on anaerobic respiration. What is another name for this process?
Glycolysis
This process needs to be amped up by the body increasing glucose consumption in order for ATP levels to be normal
The process of separating compounds in a mixture by injecting a gaseous or liquid sample into a mobile phase, typically called the carrier gas, and passing the gas through a stationary phase
gas chromatography
shorter retention times = more volatile
Long retention times on the size-exclusion chromatography column mean that the oligomers are [large/small], which also means they are more volatile. The converse is also true: short SEC retention times mean the oligomers are [large/small] and less volatile
Long retention times on the SEC column mean that the oligomers are small, which also means they are more volatile. Short SEC retention times mean the oligomers are large and less volatile
Vitamin D functions to [increase/decrease] serum calcium and ____ levels when they are low
Vitamin D increases serum calcium and phosphate levels when they are low
Antibodies are secreted by ____ into the blood and are classified as ____ immunity
B-cells, classified as humoral immunity
T-cell mediated response is classified as ____ immunity. nnate immunity refers to the general, non-specific protection the body provides (e.g., tears, skin, complement system)
cell-mediated immunity
cell-mediated immunity involve the destruction of infected cells by cytotoxic T cells, or the destruction of intracellular pathogens by macrophages
The term exogenous (wrt hormones) refers to any hormones entering the organism that are ….
not produced by the patient’s own endocrine glands.
antigen presenting cells (APCs) express which class of MHC proteins?
Both MHC class I and II
True or False
All nucleated cells express MHC I
True
High citric acid levels suggest increased substrate supply (acetyl-CoA) to the Krebs cycle. This would [postively/negatively] regulate PFK in order to [slow down/speed up] glycolysis, thus [reducing/increasing] the availability of acetyl-CoA to the Krebs cycle
High citric acid levels suggest increased substrate supply (acetyl-CoA) to the Krebs cycle. This would negatively regulate PFK in order to slow down glycolysis, thus reducing the availability of acetyl-CoA to the Krebs cycle
Low ATP/ADP and NADH/NAD+ ratios suggest that the energy levels of the cell are ….
Low
atp/adp ratio also determines if cell metabolism is predominantly oxidative or glycolytic
RT-PCR is performed on RNA, to….
give information on gene expression
RT-PCR is reverse transcription-polymerase chain reaction
Each round of beta-oxidation produces….
1 acetyl-CoA, 1 NADH, 1 FADH2, decreasing the fatty acid chain length by two carbons
