Membrane transport

Question 1

plasma membrane

Answer 1

defines all boundaries of the cell, governs interactions with other cells, controls passage of materials in/out of cell
- 98% lipids of those 75% phospholipids
- arranged in bilayer

Question 2

transmembrane proteins

Answer 2

pass completely through the phospholipid bilayer protruding from its on both sides
-mostly glycoproteins bound tot oligosaccharides on outside

Question 3

peripheral proteins

Answer 3

don’t protrude but adhere to either inner/outer face of membrane

Question 4

functions of membrane proteins

Answer 4

receptors, enzymes, channels proteins, carriers, cell-identity markers, and cell adhesion molecules

Question 5

receptors

Answer 5

surface proteins that chemical signals (that can’t enter cell) bind to

Question 6

enzymes

Answer 6

carry out final stages of starch and protein digestion in small intestine, help produce second messengers and break down hormones/other signaling molecules who’s job is done

Question 7

channel proteins

Answer 7

passages that allow water and hydrophilic solutes to move through membrane

Question 8

leak channel

Answer 8

always open and allow materials to pass continually

Question 9

gate channel

Answer 9

open/close under different circumstances
-respond to 3 stimuli

Question 10

ligand gated

Answer 10

respond to chemical messengers

Question 11

voltage gated

Answer 11

respond to changes in electrical potential

Question 12

mechanically gated

Answer 12

respond to physical stress on cell

Question 13

carriers

Answer 13

transmembrane proteins that bind to glucose, electrolytes and other solutes and transfers them to other side of membranes

Question 14

cell identity markers

Answer 14

glycoprotein acting as a cell identity markers that enables immune system to differentiate body’s own cell from foreign cells

Question 15

cell adhesion molecules

Answer 15

help cells adhere to one another and extracellular material

Question 16

second messengers

Answer 16

first hormone binds to a surface receptor , receptor is linked on the intracellular side of a peripheral G protein, when activated G-protein relays signal to adenylate cyclase, adenylate cyclase removes 2 phosphate groups from ATP and converts it to cAMP the second messenger, cAMP then activated kinases which add phosphate groups to other cellular enzymes

Question 17

gylcocalyx

Answer 17

fuzzy coat external to plasma membrane composed of carbohydrate moieties of membrane glycolipids and glycoproteins
- allows body to distinguish its own healthy cells from transplanted tissues, invading organisms and diseased cells

Question 18

microvilli

Answer 18

extensions of plasma membrane that serve to increase a cells surface area

Question 19

Brush border

Answer 19

dense fringe of microvilli

Question 20

cilia

Answer 20

hairlike processes, nearly every cell has one primary one

Question 21

motile cilia

Answer 21

less widespread but more numerous when present

Question 22

flagellum

Answer 22

only one present is the whiplike tail of sperm
-more snakelike or corkscrew fashion that cilium

Question 23

pseudopods

Answer 23

cytoplasm filled extensions of the cell varying in shape
- change continually and help cells more around and grab things

Question 24

selectively permeable

Answer 24

allows some things through but prevents other things from entering/leaving

Question 25

passive

Answer 25

require no energy expenditure - filtration, diffusion, osmosis

Question 26

active

Answer 26

require energy -active transport and vesicular transport

Question 27

carrier mediated

Answer 27

use a membrane protein to transport substances from one side of membrane to the other

Question 28

filtration

Answer 28

when physical pressure forces fluid through a selectively permeable membrane - blood capillaries were blood pressure forces fluid through gaps

Question 29

simple diffusion

Answer 29

net movement of particles from high concentration to lower concentration as result of constant spontaneous motion - rates affected by temp, molecular weight, steepness of concentration gradient, membrane surfaced area, membrane permeability

Question 30

osmosis

Answer 30

net flow of water from one side of a membrane to another, from more watery side to least watery side

Question 31

hydrostatic pressure

Answer 31

force exerted against a surface by a liquid

Question 32

osmotic pressure

Answer 32

hydrostatic pressure required to halt osmosis

Question 33

reverse osmosis

Answer 33

mechanical pressure applied to one side of the system can override osmotic pressure and drive water through membrane agains its gradient

Question 34

osmolarity

Answer 34

osmotic concentration, milliosmoles per liter, the quantity of non permeating particles per liter

Question 35

tonicity

Answer 35

ability of a solution to affect the fluid volume and pressure in a cell

Question 36

hypotonic

Answer 36

has lower concentration of non permeating solutes than ICF, cell gain too much water

Question 37

hypertonic

Answer 37

solution with higher concentration of non permeating solutes than ICF, cell shrivels

Question 38

isotonic

Answer 38

concentration of non permeating solutes is same as ICF

Question 39

carrier mediated transport

Answer 39

when a solute binds tot a carrier in plasma membrane which then changes shape and releases solute to other side

Question 40

transport maximum

Answer 40

when carriers are saturated and no more are available to handle increased demand

Question 41

uniports

Answer 41

carry only 1 type of solute

Question 42

symport

Answer 42

can more 2 or more solutes simultaneously by process of cotransport

Question 43

antiport

Answer 43

uses counter transport to move 2 or more solutes in opposite directions

Question 44

facilitated diffusion

Answer 44

transport of solute through membrane down its concentration gradient

Question 45

primary active transport

Answer 45

moves substances through membrane up its concentration gradient

Question 46

secondary active transport

Answer 46

depends indirectly on ATP, solute hitches a ride on incoming Na and Na combine sure to low Na concentration because of Na-K pump that depends on ATP

Question 47

vesicular transport

Answer 47

move large particles, droplets of fluid or numerous molecules atop; once through membrane

Question 48

endocytosis

Answer 48

brings matter into cell

Question 49

phagocytosis

Answer 49

process of cell engulfing particles like bacteria, dust and cellular debris

Question 50

phasgosome

Answer 50

vesicle of white blood cells that surrounds bacterium and then be destroyed

Question 51

pinocytosis

Answer 51

"cell drinking", process of taking in water droplets of ECF that contain molecules of some use to the cell

Question 52

receptor mediated endocytosis

Answer 52

enables cell to take in specific. molecules from ECF w/minimum of unnecessary matter

Question 53

transcytosis

Answer 53

transport of material across cell

Question 54

exocytosis

Answer 54

release of material from cell