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physiiology ch6
leggett
Question | Answer |
---|---|
cell membranes are composed primarily of ? | proteins and lipids |
approximate percentage that is proteins and lipids | 55%protein , 25% phospholipid, 13% cholesterol , 4 % other lipids, and 3% carbohydrates |
2 types of lipids | phosopholipids and cholesterol |
what is meant by lipid bilayer? | fat soluble molecules can pass through it |
as a general rule is the lipid barrier water soluble? | yes |
fluid mossiac model | bi layer is fluid not rigid molecules may move latertally |
most proteins in the cell membrane are? | glycoproteins |
integral proteins are? | passes all the way through the cm. channel , enzymes, and carrier proteins |
peripheral prteins are? | attached only to the surface of the cell membrane. usually an enzyme |
endocytosis is? | the movement of molecules into a cell that are too large to enter. pinocytosis,phagocytosis,and receptor-mediated |
exocytosis is? | the reverse of endocytosis |
what 2 general processes do small molecules use to pass through a cell membrane? | diffusion and active transport |
diffusion is? | the net moveemoent of molecules higher to lower. 3 factors effecting this are: magnitude of cencentration gradient,permability of the cmto the diffusing, and surface area. |
is a carrier protein required for simple diffusion? | no |
2 types of simple diffusion | direct movement through the cm and movement through watery channels |
do all types of channels use simple diffusion? | yes |
osmosis is | the flow of water molecule through a selectively permiable membrane from ares of greater to lesser concentration. |
osmosis conditions | 2 compartments of water, seperated by selectivly permiable membrane, concentration difference |
will non permiable particle pass through the membrane? | no |
osmotic preassure | the amount of preassure that must be applies to prevent the flow of water during osmosis |
what determines the magnitude of osmotic preassure? | concentration of solute to the # of solvent the greater solute the greater OP |
3 ways to increase solute concentration? | increase # of particles, decrease # of solvent |
2 formulas for concentration? | molarity=moles/liters osmolarity=osmoles/liters |
how many molecules of a given compound are there in one mole? | 6.02*10 ^ 23 |
how many in one osmole? | 6.02 * 10^23 |
formula for molarity to osmolarity? | molarity X number of particles/molecule=osm |
osmolarity | describes the # of particles per liter of solution |
isomotic | the osmolarity of 2 solutions are the same |
hyperosmotic | the osm. of the first is greater then the second |
hyposmotic | the osm of the first is less then the second |
tonicity | term that describes what happens to the cell volume when the cell is placed in solution |
tonicity depends on what? | comparisson of osm of the solution to cell and nature of the particles |
crenation | to shrink |
hemolysis | to rupture |
what requires the push for facillitated diffusion? | concentration gradient and carrier protein is needed |
active transport? | movement of ions or molecules from an area of lesser to greater |
cotransporter (symport) | same direction |
counter transporter (antiport) | different directions |
what are the intrinsic controol mechanisms of cellular metabolism? | genetic regulation, enzyme activity |
exocrine | enters a tube that lead to a free surface |
endocrine | goes directly into the blood |
hormone | chemical substance realeased into blood |
classification of hormones by structure | dirivapolypeptides and glycoproteins tives of amino acid tyrosine, steroids |
why do some cells respond to hormones? | b/c of receptors |
alternate names for ant and post pituitary | adenohypophysis and neurohypophysis |
what controls secretion from endocrine gland? | intrinsic control mechanisms |
what is meant by down and up regulation? | decrease in # of receptors and increase |
another name for growth hormone? | somatotropin |
catabolic effect of GH? | direct effect |
anabolic effect of GH? | indirect effect |
somatomedians | insulin like growth factors |
gigantism | excessive GH in children |
acromegaly | excessive GH in adults |
what hormones are produced by thyroid? | t3(active) t4 thyroid hormones TSH |
t3 causes | stimulates protein synthesis needed for growth premotes developement helps set the basale metabolic rate |
two regions of adrenal gland | medulla and cortex |
adrenal gland | releases epinephrine |
function of aldosterone | helps regulate sodium and potassium |
whats releases glucagon and the effects | secreated in response to blood glucose levels, glycogenolysis,glucogenesis, and lipolysis |
what stimulates the release of insulin | increase blood glucose levels, |
effects of insulin | needed for movement of glucose liver adipose tissue inhibits secretion of glucogen |
sensitivity to insulin receptors | increased by excersise decreased by obesity and pregnancy |
symptoms of diabetes | cronic high blood glucose |
different form of diabetes | insulin dependant and non insulin dependant |