| 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 |
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