cell membrane 2 Flashcards
what’s the average composition of the cell membrane
55% proteins
45% lipids
small amount of carbohydrates
what are the type of lipids found in the cell membrane
phospholipids
sphingolipids
cholesterol
what does amphipathic mean
one region that really likes water and one region that doesn’t
what does cholesterol do?
makes the cell have more viscosity because phospholipids are so fluent that they’d just fall apart
what’s the major lipid in the cell membrane
phospholipid
what lipids are involved in lipid rafts
sphingolipids
what are the main categories of cell membrane proteins (2)
integral and peripheral
what is an integrated protein?
its integrated into the membrane. transmembrane proteins and lipid anchored proteins
what is a peripheral protein
its not attached to the membrane
attached to integral proteins
what is caveolae
the area of the membrane that sinks in rather than comes out
what are the two types of lips rafts
planar lipid rafts
caveolae
what side of the membrane are cell membrane carbohydrates always on
extracellular
what’s a glycoprotein
protein with a carbohydrate attached on the extracellular membrane
what’s a glycolipid
lipid with a carbohydrate attached on the extracellular layer
what are glycolipids and glycoproteins used for ?
cell to cell recognition
identify antigens
cell to cell interactions
is stuff always moving between body fluid compartments
always moving between
what does the ECF consist of
interstitial fluid
blood plasma
what is blood plasma
the liquid in the matrix of the bloood
what is the interstitial fluid
it lies between the circulatory system and the cell
how much % of the body is water
60%
which gender has lower total body content ? why?
females - adipose tissue
what is adipose tissue
basically fast tissue
what does skeletal muscle become as we age
adipose tissue
what is the majority of adipose tissue made of
lipids (90%)
the rest is water
what does less body fat mean in relation to water
the less body fat, the more water
what is equal is osmotic equilibrium?
fluid concentration - amount of solute per volume solution
what is osmosis
the movement of water across a membrane in response to a solute concentration gradient
what are aquaporins
water channels
are aquaporins always open
yes
intracellular fluid is ________ charged compared to extracellular fluid
negatively
what is osmotic pressure
quantifying the drive for fluid movement across a selectively permeable membrane
is osmotic pressure measurable
yes
what does osmolarity describe
the number of solute particles dissolved in a solution
what does osmotically active particles mean
of particles that will drive osmosis
what does tonicity describe
a solution in reference to a cell volume changes
is tonicity measurable
no it is not a meaurable term
it is observable/ comparable
what’s a bad thing about osmolarity
it doesn’t tell you what happens to a cell
what does tonicity depend on
the concentration of non penetrating solutes
can water move freely between ECF and ICF
yes
