MCAT Stuff IDK Flashcards
What happened in the Loop of Henle?
sodium is reabsorbed from the filtrate and urine is concentrated
What causes depolarization in neurons?
the influx of sodium through the voltage-gated ion channels causes depolarization down the nodes of Ranvier (unmyelinated)
When are leukocytes administered?
when there is inflammation
What comprises the extracellular fluids?
blood plasma and lymph
What does anaerobic mean?
there’s no oxygen or glyocysis
How do bacteria reproduce?
through conjugation by the use of F-factor plasmids
What is the diff b/w exo and endocrine secretion?
exocrine = secreted into ducts
endocrine = secreted into blood
What is the process of inhalation?
inhalation in the lungs is a negative pressure pumping in which the pressure of the lungs. is lower than the atmospheric pressure
Where do steroids bind?
steroids must bind on carrier protein receptors in the cytoplasm of the nucleus
What is the diff b/w alpha and beta islets of the pancreas?
beta = insulin
alpha = glucagon
What are the physiological effects of parathyroid?
increase calcium reabsorption in the kidneys and intestines, and increase osteoclast to increase calcium levels in the blood
What is the role of aldosterone?
increase BP by increasing water reabsorption
What happens in hypertension?
BP increases which means hydrostatic pressure of the BV also increases, glomerular filtration rates increase so you can pee, but oncotic pressure remains constant
What causes vasoconstriction?
pressures of smooth muscle in the wall of the blood vessels
Which hormones use a positive feedback system?
Oxytocin during uterine contraction at the time of birth
blood clotting
LH and estrogen in ovulaltion
Prolactin in breastfeeding
What is the role of somatostatin?
turns off growth hormone
What are the physiological effects of cortisol?
decrease glucose uptake, protein synthesis, and glycogen storage
increase protein breakdown, gluconeogenesis (breakdown of glycogen to G6P), and lipolysis
What are the physiological effects of insulin?
insulin is secreted by the beta cells of the pancreas upon feeding, singling cells to increase the uptake of glucose, and protein synthesis and store glycogen to decrease blood sugar
decreases protein breakdown, gluconeogenesis, and lipolysis
What does an uncompetitive inhibitor do?
binds to the ES complex
Vmax and Km are both lowered
What does a noncompetitive inhibitor do?
binds to a location other than the active site
Km remains the same, Vmax decreases
What does a competitive inhibitor do?
binds reversibly to the active site
Vmax is unchanged, but Km increases
What happens when the kidneys sense low BP?
Baraorecetors in the kidneys sense low BP, and release Renin
Renin activates angiotensinogen made in the liver by cleaving it to angiotensin
ACE released by the lungs converts angiotensin I to II
Angiotensin II raises BP by activating the sympathetic system to stimulate the adrenal cortex to release aldosterone, vasoconstrict the arterioles, and stimulate the post. pit to release ADH
When can you apply kinematic equations?
when force and acceleration are constant or unchanging
What are the linkages of starch/glucose, glycogen, and cellulose?
starch = alpha 1,6
glycogen = alpha 1,4
cellulose = beta 1,4
What is the diff b/w eno and exonuclease?
endonuclease - cut at the end of the strand as in mismatch repair
exonuclease - cut in the middle of the strand as in restriction enzymes that cut at a palindromic sequence
What are the different uses of Southern, Northern, Eastern, and Western blots?
Southern - DNA
Northern - RNA
Eastern - lipids
Western - separates specific proteins
What are the caveats of a palindromic sequence?
must be an even number of nucleotides in the sequence
an A must be next to a T and a C next to a G (ATCG or TAGC)
must be at least 4 nucleotides long
What proteins are mostly found in alpha helices?
M, R, A, L, and K
What proteins are mostly found in Beta sheets?
P and G
What does SD-PAGE do?
makes all proteins negative charge to denature them so it can separate the proteins based on molecular weight (small proteins eluate faster)
What are the motor proteins?
myosin, kinesin, and dynein
What are the structural proteins?
collagen, keratin, elastin, actin, and tubulin
What is the strength of intermolecular forces?
Hydrogen > dipole-dipole > long-disperson
What is the diff b/w neutralization and hydrolysis?
neutralization - acid + base = salt + water
hydrolysis - salt + water = acid + base
What happens in the bicarbonate system when pH increases or decreases?
pH inc - repsiration occurs to blow out CO2
ph dec - respiration slows down to trap CO2
What is the diff b/w isothermal, baric, choric/volumetric, and adiabatic systems?
isothermal = constant temp
isobaric = constant pressure
isochoric/volumetric = constant volume
adiabtic = no exhcnga ein heat
What is enthalpy (change in H)?
solid - liquid - gas = endothermic system
gas-liquid - solid = exothermic system
Dehydrogenase
involves e’ careers NADH as in the PPP and TCA
Isomerase
generates isomers
ex: G6P to F6P
Mutase
change the number
ex: G6p to G1p, and 3PG to 2PG
epimerase
generate epimers of sugars
ex: R5P to Xy5P
Kinase
uses ATP to add organic phosphate
ex: glucose to G6P
Phosphorylase
adds inorganic phosphate
Phosphatase
takes away phosphate
ex: F1,6BP to F6P
Synthetase
uses GDP to GTP and ADP to ATP to
According to Ohm’s law, what happens when the current increases?
If the current increases and resistance is constant, then voltage also increases. To increase the current when the voltage is fixed, the resistance must be decreased
What is the index of refraction?
The index of refraction of a medium is equal to the ratio of the speed of light in vacuum to the speed of light in the medium
Why is the velocity of blood flow slower in capillaries than in arteries?
The total cross-sectional area of capillaries exceeds that of arteries.
What happens when you grind a heterogenous catalyst?
Grinding a heterogeneous catalyst increases the amount of catalyst available to the reaction and therefore, increases its rate.
What happens to NADH during TCA, glycolysis?
During the TCA and glycolysis, NAD+ is reduced to form NADH. During the electron transport chain, NADH is oxidized to form NAD+.
What do transcription factors do?
transcription factors regulate the expression of other genes by binding to the promoter or the enhancer of the gene located in the DNA.
What is the function of the Na+K+ ATPase during a neuronal action potential?
Restoration of the resting potential.
Upon ATP hydrolysis, three Na+ are transported outside the cell and two K+ are transported inside the cell against their concentration gradient.
What does leptin do?
leptin decreases insulin levels to decrease appetite and give the feeling of satiety
What does CCK do?
Cholesctokin is secreted by the duodenum to stimulate the pancreas to release digestive enzymes and the gallbladder to release bile
What does ghrelin do?
ghrelin is stimulated by the stomach wall during the fasted state to single to the brain you’re hungry
What do parietal cells secrete?
parietal cells are cells in the epithelial that secret HCL. They use the H/K ATPase to pump H against its concentration gradient
What do acinar cells secrete?
pancreatic cells that secrete bicarbonate in response to secretin
What do chief cells secrete?
pepsinogen and gastric juices
How do Enzymes alter the rate of chemical reactions?
co-localizing substrates, altering local pH, and altering substrate shape.
Which phase in the cell cycle are cells NOT dividing?
Cells that are in interphase are not actively dividing.
Describe erythrocytes
are unnucleated and thus do not contain DNA material
which cells are most important in the exchange of O2 between the blood and the surrounding tissues?
Endothelial cells are the cells that are in direct contact with blood and the surrounding matrix so these are the cells that play the most important role in gas exchange.
How are nucleotides linked with one another?
Nucleotides are linked to one another by phosphodiester bonds between a hydroxyl group of the sugar base of the nucleotide at the 5′ (thymine, cytosine) end and the phosphate group of the adjacent nucleotide at the 3′ end (adenine, guanine).
During an action potential, the movement of sodium ions into a neuron causes the neuronal membrane to?
the flux of sodium into the cytoplasm of the cell would result in a reduction of the membrane potential and thus depolarization.
Repolarization occurs after the membrane has been depolarized and is due to the opening of potassium channels.
Describe the negative feedback loop of adrenocorticotropic hormone (ACTH)
The release of ACTH from the pituitary is regulated by negative feedback. In normal conditions, high levels of circulating glucose and other stressors activate the production of corticotropin-releasing hormone (CRH) from the hypothalamus. CRH will stimulate the pituitary gland to release ACTH which will trigger cortisol release from the adrenal cortex. Finally, the presence of high levels of circulating cortisol will inhibit CRH secretion (negative feedback) thus closing the loop.
What is the physiological response of glucocorticoids?
Glucocorticoids suppress immune function, by decreasing white blood cells, and increasing protein degradation in various tissues, including muscles.
Regular exercise would most likely reduce blood glucose levels in patients with which type(s) of diabetes?
As working skeletal muscles are insulin-independent, exercise will reduce the levels of insulin in both types of diabetes
What is the diff b/w type 1 and 2 diabetes?
Many cases of Type 1 diabetes, in which the body is unable to produce insulin, are caused by an autoimmune response directed against pancreatic β cells. While the body often produces normal-to-elevated amounts of insulin in Type 2 diabetes, its ability to respond to insulin is compromised.
What are the physiological effects of diabetes?
In diabetes, the ability of many types of cells to take up glucose is compromised, leading to elevated blood glucose levels. Many tissues then metabolize fatty acids as an alternative energy source, which can lead to metabolic acidosis, a condition of low blood pH. Diabetes can also cause protein degradation, resulting in the release of excess amino acids that can be used as substrates for gluconeogenesis, which further increases blood glucose levels.
An RNA molecule has 1500 bases. What is the maximum number of amino acids it can encode?
Each amino acid is coded by a triplet of nucleobases (codon). Thus, 1500/3 = 500 amino acids.
What is the State dependency effect?
A state dependency effect refers to the benefit of a match between the conditions (in particular, the subject’s mental and emotional state) under which information is encoded into memory and the conditions present when the subject attempts to retrieve that information.
What is the diff b/w the primary effect and the recency effect?
primacy effect - item at the beginning of a series is better remembered
recent effect - items at the end of a list are generally recalled better than items presented in the middle
What is Dual-coding?
Dual-coding refers to the retrieval advantage of verbal items that are imageable. These items are encoded with both a verbal code and a visual code, which benefits their retrievability.
Concrete operational stage
According to Piaget’s theory of cognitive development, mastery of conservation is the criterion for entering the concrete operations stage, which starts at approximately 7 years and ends around 11 to 12 years.
What is the difference b/w pos and negative punishment
Positive punishment refers to the decrease in the frequency of a response resulting from the introduction of an aversive stimulus following that response.
Negative punishment refers to the decrease in the frequency of a response resulting from the removal of an appetitive stimulus following that response
What is the role of the reticular formation?
The reticular formation (RF), deep in the brainstem, is concerned with functions involving arousal, particularly the sleep-wake cycle, and attention.
What is the role of the Somatic NS?
The somatic nervous system is the division of the peripheral nervous system that controls sensory and motor functions of effectors that enable the organism to deal with its external environment.
What is a longitudinal study?
a type f observational study collecting data over an extended period to observe changes or patterns in behaviors or attitudes
What is an observational study?
observing and collecting data about a group w/o manipulating it to determine correlation
What is an experimental study?
manipulation of groups by the experimenter
What is a cross-sectional study?
an obs study design that gathers data from a population or subset population at a specific time point
What is a retrospective study?
a type of longitudinal study where researchers follow and observe a group using info taken on events from the past
What is the actor-observer bias?
According to the actor-observer bias, observers will attribute their bad behavior to situational factors (not feeling well), whereas observers will attribute actors’ behavior to dispositional factors (social awkwardness).
What does optimal arousal theory state?
Optimal arousal theory states that optimal performance requires optimal arousal and that arousal levels that are too high or too low will impede performance.
What is the diff b/w positive and negative priming?
Priming of positive stereotypes facilitates performance, while negative interferes with it
what is the role of the cerebellum?
the motor task, and movement
What is Social support?
Social support typically refers to the tangible and intangible forms of assistance that individuals receive from their social ties.
What is network analysis?
Network analysis involves mapping the social relationships that exist among a set of individuals.
What is Assilimatin?
Assimilation refers to the process in which new members of a society adopt the norms and values of the dominant culture. Each of the other options provides an element of assimilation (cultural adaptation, adopting new norms, and relinquishing old norms).
What is Weber’s Law?
Weber’s Law is the name given to the robust psychophysical observation that the just noticeable difference (JND) between two physical stimuli is a constant proportion (i.e., Weber’s constant) of the original (or standard) stimulus.
What is The Schachter-Singer two-factor theory?
The Schachter-Singer two-factor theory is concerned with explaining the relation between emotions and cognitive awareness of one’s emotional state
What is The nativist hypothesis?
The nativist hypothesis is concerned with the acquisition of a child’s first language
what is a case study?
A case study focuses on the examination of a single case
According to Boyle’s law, what happens when you double pressure?
Based on Boyle’s Law, P is inversely proportional to volume, thus, doubling the pressure of a gas sample will decrease, not increase, the volume.
Which of the following species has an electron configuration equivalent to that of a noble gas? Ca2+ or Cu2+
Ca2+ B/c it lost 2e’, and thus will be 18 instead of 20, and 18e is Ar noble gas
Charge of a capacitor
Q = CV
If the 25 μF capacitor in the defibrillator is replaced with a 30 μF capacitor, what new power supply setting would produce the same amount of charge?
On the 25 μF capacitor, the power supply stores a charge of 25 μF × 3000 V = 75 mC. On the 30 μF capacitor, the same charge is stored by a power supply that has a voltage of 75 mC/30 μF = 2500 V.
If the red line in the Balmer series has a wavelength of 656 nm, what is its frequency?
For light that travels in vacuum, wavelength and frequency are related according to wavelength × frequency = 3.0 × 108 m/s. Solving for frequency yields (3.0 × 108 m/s)/(656 × 10-9 m) = 4.6 × 1014 Hz.
What is the value of Kb for the conjugate base of a weak organic acid that has a pKa of 5?
A.10−2.5
B.10−5
C.10−9
D.10−1
Because pKb = 14 - pKa, the Kb for the conjugate base = 14 - 5 = 9
