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113 Cards in this Set
- Front
- Back
the pm is generally not permeable to _____, ____, ____, & _____.
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proteins, nucleic acids, large molecule, & structural molecules
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the pm is permeable to small ______, & ______
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small molecules, & lipid soluble substances
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the pm is selectively permeable to _____ & ______, which travel through the pm via channels
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ions, water
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transport across mb that does not require energy, nor a carrier, & travels down the concentration gradient:
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diffusion
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transport across pm from higher to lower conc., energetically favorable, includes carrier & non-carriers:
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passive transport
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when a substance is transported across pm down the concentration gradient, it moves from ____ to _____ concentration
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higher to lower
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what is active transport?
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lower to higher (up/against gradient), requires energy, & carrier protein
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diffusion of lipid soluble mo. thru pm, ions (sm. uncharged) thru ch. proteins, & water thru aquaporins are examples of _______ transport
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non-carrier mediated/ passive
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2 types of carrier mediated transport are ____, & _____
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facilitated diffusion, & active transport
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solute in a solvent is in random constant motion. this rate depends on ______
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heat (thermal heat energy)
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a solution consists of ____, & ____
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solvent, & solute molecules (book also says water)
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_____ in a solution is in random constant motion
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solute
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if a conc. diff, random motion of solute spreads out. this random motion is _____
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diffusion
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as a result of random molecular motion, most molecules move from higher to lower conc. until equal, this net movement is ______
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net diffusion
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waste molecules can be removed from the blood by having them diffuse through an ARTIFICIAL porous mb. this is called ______
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dialysis
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factors that contribute to the rate of diffusion are
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steepness of conc. gradient, 2-permeability of substance, 3-temp of solution, 4-mb surface area
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areas of body specialized for diffusion/absorption (i.e. GI tract) are often folded or contain microvilli. Why?
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to increase the surface area so molecules move more rapidly
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why do neurons use axons for diffusion?
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because distance is too long for diffusion
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5 lipid soluble molecules that can diffuse the pm are:
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O2, CO2, steroid hormones, alcohol, & some drugs (book also says ethanol & urea)
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steroid hormones have a ______nucleus
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cholesterol
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can water diffuse the pm?
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yes, if it is small, through aguaporin channels, osmosis
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large polar molecules require ____ to diffuse the pm
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carrier protein
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charged ions such as Na+ & K+ are impermeable. how do they get across the pm?
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via ion channels, either gated (pump), or non gated
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what 3 triggers can open gated ion channels?
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ligand binding, mechanical stretch, & mb voltage
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in the production of nerve & muscle impulses, specific ch's for ___ & ___ open & close in response to mb voltage
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Na+ & K+
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when your bladder is full it activates calcium to be released, which activates contraction. this is an example of:
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mechanical stretch
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what is osmosis?
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net diffusion of water (solvent) across a mb
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what is required for osmosis? (4)
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1-mb allows water mvmt, but not solute, 2-conc. gradient of solute (must be diff in conc), 3-higher to lower water conc, 4-aquaporins
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when solution is more dilute on 1 side of pm than the other, the more dilute solution has higher conc of ____, & lower conc of ____
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water molecules, solute
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when can osmosis occur?
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when water is more concentrated on one side than the other
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what is osmotic pressure?
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the pressure req. to stop osmosis
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because it is a measure of the force req. to stop osmosis, what does OSMP (osmotic pressure) indicate?
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how strongly a solution draws water by osmosis
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the greater the ______, the greater the OSMP
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solute concentration
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solutes that cant freely pass thru the mb can promote the osmotic mvmt of water & are said to be ____
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osmotically active
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what is excessive accumulation of fluid in the tissues called?
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edema
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what is liver cirrhosis?
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a damaged liver that is unable to produce sufficient amounts of albumin. can result in edema
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plasma proteins (such as albumin) cant freely pass from the capillaries to the tissue fluid, therefore they are considered to be ________
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osmotically active
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what is kwashiokor?
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protein malnutrition- (for children it ↓ IGF1 plasma protein, ↓ growth rate, & ↑ growth hormone. can result in giantism)
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_____ may result from abnormally low conc of plasma proteins, liver cirrhosis, or kwashiokor
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edema
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osmosis occurs when the water is (more? or less?) conc on one side than the other.
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more
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pure water has an OSMP of zero. A 360 g/L glucose solution has _____ the OSMP of 180g/L glucose solution
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twice
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what is molarity?
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way to define solute in a solution. 1 mole of solute in 1 L solution= 1 molar solution
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a way to define ratio of solute to water. 1 mole per kg (1 L) water= 1 molal
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molality
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when measuring molality, does the amount of water vary between solutions?
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no
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1 mole of NaCl= ___ Osm
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2
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if you take the solute: 1 mole of glucose (180g), & fill beaker up to 1 L mark with water, which will you have: 1 molar, or 1 molal?
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1 molar
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molarity X the # of dissociable ions, or the total molarity of a solution, is called ______
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osmolarity
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osmolarity depends on ______ & ______. the ratio of solute to solvent is very important
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osmotic pressure & solute molecules
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if you take solute: 1 mole of glucose (180g), & add 1 Kg (1 L) water, which will you have: 1 molar or 1 molal?
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1 molal
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1 mole of glucose Vs 1 mole of NaCl. which has more OSMP?
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NaCl
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what would happen if a rbc were placed in a hypotonic solution?
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lysis
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if a solution, has the same has the same osmolarity as plasma, it is _______ to plasma
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isosmotic
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plasma= ___ Osm, or ___ mOsm
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.3 Osm, or 300 mOsm
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______ & _____ are isosmotic to plasma
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5% dextrose & normal saline
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in an _____ solution, osmosis will not occur betw. solution & plasma
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isotonic
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a solution >300mOsm is ____-tonic
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hypertonic
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if an isosmotic glucose or saline solution is separated from plasma by a mb that is permeable to water but not glucose or NaCl, will osmosis occur?
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no, the solution is said to be isotonic
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what would happen if a rbc were dropped in a hypertonic solution?
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crenation
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what is tonicity?
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used to describe how a solution effects the osmotic movement of water
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a solution <300mOsm is ____-tonic
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hypotonic
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urea is iso-_____, but not iso- _____
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isosmotic, not isotonic
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Deltoid
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Origin: clavicle and scapula (acromion and adjacent scapular spine)
Insertion: deltoid tuberosity of humerus Action: abducts shoulder, flexion and extension, medial and lateral rotation of humerus Nerve: Axillary |
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why do we say that urea is isosmotic?
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because it is freely permeable across mb
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what is Ringer's lactate?
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an isotonic solution
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what are the effects of mannitol?
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pulls water in (promotes osmosis),
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what would happen if urea were given intravenously?
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cell lysis would occur at .3M urea
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if a patient is dehydrated, it can _____their blood
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concentrate
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if a patient suffered brain trauma or stroke resulting in cerebral edema, what can they be given intravenously?
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mannitol- a hypertonic solution to reduce cell swelling
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_____ & _____ are too large for diffusion so they use a carrier to cross mb.
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glucose & amino acids
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what are 3 common characteristics of carrier proteins:
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specificity, saturation, & competition
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what does it mean when the carrier transport is saturated?
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as conc. of a transported molecule is ↑, its rate of transport will also ↑, but only up to a transport maximum. when max is reached, it is saturated
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carrier transport:
when will the rate of transport stop increasing? |
when the carrier transport reaches saturation
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what does it mean when glucose is found in a patients urine?
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glucose conc of blood & filtrate is too ↑ (hyperglycemia), so the transport max was exceeded. this usually results from inadequate secretion of insulin from diabetes mellitus, but can just be a result of a patient that recently ate a high carb meal
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which carrier proteins can bring glucose into the cell?
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GLUT glucose carriers only
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if 2 different aa (amino acids) were transported by the same carrier, would the rate of transport be (higher? or lower?) when they are present together than if they were alone.
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lower (competition)
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what does it mean when a carrier is specific?
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it can differentiate betw. substances. will only bind the molecule it is supposed to (i.e. GLUT carrier will bind glucose, but not fructose)
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what 2 things can allows cells to take up more glucose from the blood?
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exercise or insulin
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how do exercise & insulin help cells take up more glucose from the blood?
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they stimulate GLUT proteins to fuse with the mb which carry them through
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is the diffusion of glucose considered facilitated diffusion, or is it carrier mediated transport?
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both- same
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what is a binding site?
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site on a carrier protein that is made to fit a specific molecule for transport
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what type of transport requires pumps?
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active transport
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what can happen if a diabetic person overdosed their insulin?
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plasma glucose conc. abnormally ↓ (hypoglycemia), the rate of transport into brain cells may be too slow for metabolic needs, could result in loss of consciousness or death.
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what type of transport protein is referred to as a pump?
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primary active transport carrier
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when ATP breaks off its phosphate group, this energy can be used in what type of transport?
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primary active transport
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where are Ca+ pumps located?
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pm of all cells & mb of ER of striated muscle cells
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is Ca+ higher or lower inside the cell?
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lower
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name 3 primary active transport pumps:
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proton (H+), Ca+, & Na+K+
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what activates ATPase in the Ca+ pump?
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the binding of Ca+ to the binding site on the pump
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what does ATPase do in the Ca+ pump?
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hydrolyzes ATP breaking it into ADP & P (phosphate)
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what does ADP do in the Ca+ pump?
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makes a conformational change to the pump, which opens the passageway for Ca+ to move into the ECF
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what resets the Ca+ pump back to its original state so Ca+ in the cytoplasm can reach the binding site again?
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P (phosphate)
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a drastic change in cytoplasmic Ca+ could happen if ion channels were open & Ca+ rapidly rushed into the cell. this serves as a signal for _____ & _____
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nuerotransmitter release & muscle contraction
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where does striated muscle sequester (store) calcium?
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ER
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why is calcium in striated muscle important?
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for muscle contraction
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the Na+K+ pumps ____ out of the cell and ___ in the cell
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3 Na+ out & 2 K+ in
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is Na+ more conc. in the ECF or in the cytoplasm?
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Na+ is higher in the ECF
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there are 100's-1000's of these pumps in every cell:
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Na+K+ pumps
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the Na+K+ pump maintains ionic gradients essential for 3 functions:
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coupled transport (secondary active),
nerve & muscle stimulation, & osmotic balance |
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the steep gradient of the Na+K+ pump provides energy for ______
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coupled transport (secondary active)
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what is secondary active transport?
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when energy to move against a gradient (uphill) is obtained by downhill transport of a substance (usually Na+)
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for the heart to pump to the aorta, it receives an electrochemical impulse from nerve & muscle cells. which pump is responsible for this impulse?
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Na+K+
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coupled transport is also known as _____
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secondary active transport
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is ATP required for secondary active transport?
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yes but indirectly
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what is cotransport?
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symport- when 2 molecules move in the same direction across a mb together
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which pump produces electrochemical impulses in nerve & muscle cells
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Na+K+
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give an example of cotransport/ symport:
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Na+ & glucose in kidney tubules. Na+ binding enhances glucose binding. they both travel across mb into the cell together
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what is countertransport?
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antiport- when 2 molecules move in opposite directions
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is the Na+K+ pump were to stop, what would happen?
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the increased Na+ within the cell would promote the osmotic inflow of water & the cells would damage/ swell
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give an example of countertransport:
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Na+/ Ca+ exchange. Na+ goes in and Ca+ goes out
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is secondary transport energetically favorable?
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yes
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what are 2 types of transport across epithelial mb?
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transcellular transport & paracellular transport
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what is transcellular transport?
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transport of a substance across epithelial mb through the cytoplasm
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what type of transport is limited by tight junctions?
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paracellular transport (across epithelial mb)
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