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