Cell Membrane Flashcards
What do unsaturated phospholipids have?
more fluid as well as a double bond which creates a kink in the molecule.
what is entropy?
measure of disorder of things
what is osmosis?
simple diffusion of water through selectively permeable membrane
(passive process that occurs naturally)
what is a hypotonic solution?
solution with a lot of water (ex: solvent)
water moves into RBC and it lyses (bursts)
what is a hypertonic solution?
solution with less water (ex: solute)
water moves out of RBC and it becomes dehydrated
in what direction does water move?
hypotonic –> hypertonic
down concentration gradient from more water to less water
what makes a solution more hypertonic?
the more number of final particles it has
what does isotonic mean?
same number of particles inside and outside cell
what happens to RBC when places in hypotonic solution?
they lyse
what does the sodium-potassium pump do?
exports 3 Na out of cell and imports 2 K in the cell
uses ATP
moves ions against concentration gradient (from low -> high)
what is a hypotonic solution?
more particles inside cell than outside
what is a hypertonic solution?
more particles outside cell than inside
what is plasma membrane?
fragile, transparent barrier that contains cell contents and separates them from the surrounding environment
interior of plasma membrane is impermeable to?
most water-soluble molecules.
cholesterol helps keep the membrane fluid
what are proteins responsible for?
specialized functions in lipid bilayer throughout cell membrane.
receptors for hormones or other chemical messengers or are binding to sites for anchoring the cell to bikers or other structures
involved in transport
some proteins are enzymes
what are protein channels?
water and small water-soluble molecules or ions can move through them
what are carriers?
protein that binds to a substance and moves it through the membrane
what is a glycoprotein?
sugar protein
makes the cell surface sticky due to the sugar
what is glycocalyx
the fuzzy, sticky surface of the cell which is coated in sugar
what do glycoproteins determine?
blood type
are receptors for certain bacteria/viruses/toxins
cell to cell recognition
when do glycoprotein cells change?
when they transform into cancer cells
what is a solution?
homogenous mixture of 2 or more components
what is a solvent?
dissolving medium (water)
what is a solute?
disolved in solvent
what is intracellular fluid?
contains gasses, nutrients, salts and dissolves into water
what is interstitial fluid?
continuously bathes the exterior of our cells
what is selective permeability?
allows some substances to pass through while excluding others
what is passive movement?
no ATP used
what is active movemet?
ATP used
diffusion?
molecules move from high concentration to low concentration (move down their concentration gradient)
temperature and size of molecule affects speed of diffusion
what can pass through the hydrophobic barrier?
small molecules
lipid-soluble molecules
molecules assisted by membrane carrier
simple diffusion?
unassisted diffusion of solute through plasma membrane
what is filtration?
water + solutes are forced through a membrane by fluid with use of pressure gradient from higher to lower pressure
blood cells and large protein molecules are held back
active transport?
uses ATP
- active transport
- endocytosis
- exocytosis
solute pump allows passage of amino acids, sugars, ions
vesicular transport?
moves substances in/out of cell without crossing the plasma membrane by endocytosis or exocytosis
exocytosis?
contents released from cell
ATP used
endocytosis?
contents brought into cell
phagocytosis?
cell eating another cell
pinocytosis?
cell drinking another cell
passive transport: facilitated diffusion?
no ATP required
- simple diffusion (non-polar molecules)
- osmosis (hypotonic -> hypertonic)
- facilitated diffusion (polar molecules)
