Bio Chap 5

Front 1

Phospholipid bilayer

Back 1

fluid main component of plasma membrane, spontaneously form bilayers in water

Front 2

Bilayer stability

Back 2

due to water’s affinity for hydrogen bonding

Front 3

Fluid mosaic model

Back 3

says plasma membrane is composed of both lipids & globular proteins, free to move about the fluid bilayer

Front 4

Membrane proteins

Back 4

part of plasma membrane, not very soluble in water

Front 5

4 components of cellular membrane

Back 5

phos. Bilayer, transmembrane proteins, interior protein network, cell surface markers

Front 6

Phospholipid structure

Back 6

polar phospholipid head attached by glycerol (3-C polyalcohol) to two non-polar fatty-acid chains (tails)

Front 7

Transporter protein

Back 7

brings certain molecules into cell (ex: the B barrel for bringing polar substances thru)

Front 8

Enzyme (in membrane)

Back 8

binds certain molecules, changes it, releases it (on same side of plasma membrane)

Front 9

Cell surface receptors

Back 9

sends signal to cell when certain molecule binds to receptor from outside

Front 10

Cell surface identity markers

Back 10

has attached “ID tag” on outer side of membrane to identify cell

Front 11

Cell adhesion proteins

Back 11

attaches with other adhesion protein from diff cell to hold multiple cells together

Front 12

(Lipid-)anchored (or peripheral) proteins

Back 12

are anchored to phospholipid in one layer, have nonpolar regions that are inserted in bilayer, are free to move about in their environment

Front 13

Membrane proteins

Back 13

located in plasma membrane, can be anchored to lipids in bilayer

Front 14

Integral membrane proteins

Back 14

span bilayer (transmembrane), have at least one transmembrane domain

Front 15

Transmembrane protein “pore”

Back 15

formed by extensive nonpolar regions within transmembrane protein, B sheets form cylinder called B-barrel, whose interior is polar (allows water, small polar molecules to pass)

Front 16

Passive transport

Back 16

no energy is required, molecules move thru membrane in response to a concentration gradient

Front 17

Diffusion

Back 17

mvmt of molecules from high to low concentration, result of random motion

Front 18

Selective permeability

Back 18

integral membrane proteins allow cell to be selective about what passes thru

Front 19

Channel proteins

Back 19

have polar interior that lets polar molecules pass thru

Front 20

Carrier proteins

Back 20

bind to specific molecule to facilitate its passage

Front 21

Ion channel

Back 21

(in channel proteins) allow passage of ions associated with water

Front 22

Gated channels

Back 22

(in channel proteins) opened or closed in response to stimuli (chem or electrical)

Front 23

Facilitated diffusion

Back 23

specific, passive transport where carrier proteins bind to ions, other solutes on one side of membrane and release them on the other, incr in conc gradient does not affect rate of mvmt of molecules

Front 24

Osmosis

Back 24

mvmt of water from high to low concentration of water (towards area of high solute concentration)

Front 25

Osmotic concentration

Back 25

concentration of all solutes in solution

Front 26

Hyperosmotic (hypertonic)

Back 26

solution with higher solute concentration

Front 27

Hypoosmotic (hypotonic)

Back 27

solution with lower solute concentration

Front 28

Isosmotic (isotonic)

Back 28

solute concentrations are equal

Front 29

Hydrostatic pressure

Back 29

pressure of cytoplasm pushing against cell membrane

Front 30

Osmotic pressure

Back 30

pressure necessary to stop osmotic mvmt of water across membrane

Front 31

Cell in hypotonic solution

Back 31

swells, creates pressure inside, IF membrane is strong enough (NOT animal cells), balance is reached between osmotic (water in) and hydrostatic (water out) pressure

Front 32

Maintaining osmotic balance

Back 32

extrusion, isosmotic regulation, turgor pressure (plant cells)

Front 33

Extrusion

Back 33

water ejected through contractile vacuoles

Front 34

Turgor pressure

Back 34

used in plant cells to push cell membrane against cell wall and keep cell rigid

Front 35

Active transport

Back 35

requires energy (ATP required directly or indirectly), moves from low to high concentration, uses carrier proteins

Front 36

Na+-K+ pump

Back 36

active transport mechanism, symporter

Front 37

Secondary active transport

Back 37

coupled transport that uses energy from diffusion mvmt of one molecule to supply energy to active transport of diff molecule

Front 38

Uniporter

Back 38

moves one molecule at a time in secondary active transport

Front 39

Symporter

Back 39

moves two molecules in same direction in secondary active transport

Front 40

Antiporters

Back 40

moves two molecules in opp directions in secondary active transport

Front 41

Bulk transport

Back 41

accomplished by endocytosis (into cell) and exocytosis (out of cell)

Front 42

Exocytosis

Back 42

material is discharged from the cell, vesicles in cytoplasm fuse w/ cell membrane and release contents to exterior, used to secrete hormones, neurotransmitters, digestive enzymes