cell organization? forget what lecture is called

Question 1

protein in membrane

Answer 1

N side extracellular, C side intracellular, alpha helix inside membrane

Question 2

functions of membrane proteins (6)

Answer 2

transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining/adhesing, attachment to cytoskeleton and extracellular matrix

Question 3

peripheral proteins

Answer 3

, sit on other proteins attached to plasma membrane

Question 4

solution

Answer 4

solvent the liquid, in which the solute is dissolved

Question 5

solute

Answer 5

could be molecule

Question 6

isotonic solutions

Answer 6

when comparing two solutions, same concentrations

Question 7

hypotonic solution

Answer 7

when comparing two solutions, one with lower concentration

Question 8

hypertonic solution

Answer 8

when comparing two solutions, one with higher concentration

Question 9

H-bonds in water

Answer 9

electronegativity gives attraction for H-bonds, dissolve things (ex. NaCl); hydration shells

Question 10

passive transport

Answer 10

diffusion, osmosis

Question 11

diffusion

Answer 11

the movement of solutes down a concentration gradient, a permeable membrane does not impede diffusion, diffuse until equilibrium

Question 12

osmosis

Answer 12

the movement of WATER along a concentration gradient through a semi or selectively permeable membrane to one or more solutes

Question 13

osmosis in red blood cells

Answer 13

cell will burst/lyse in hypotonic solution, cell will shrivel in hypertonic solution, *normal in isotonic

Question 14

osmosis in plant cells

Answer 14

cell turgid *(normal) in hypotonic solution because pressure in cell wall gives turgidy, cell flaccid in isotonic solution, cell plasmolyzed in hypertonic solution (shrinks)

Question 15

unicellular organisms and osmoregulation

Answer 15

hypotonic outside, hypertonic inside, collects water in contractile vacuole (when full, will expel water)

Question 16

simple/passive diffusion

Answer 16

passes through membrane (semi, selectively, or permeable)

Question 17

passive facilitated diffusion

Answer 17

through channel/transport protein in membrane

Question 18

active transport

Answer 18

require ATP and energy to bring in solute against concentration gradient

Question 19

polar molecules permeability

Answer 19

amino acids, sugars, and charges substances such as ions, cannot easily diffuse across lipid bilayers even if concentration gradient exists

Question 20

high permeable molecules

Answer 20

small, non-polar molecules: ex. O2, CO2, N2

Question 21

permeable molecules

Answer 21

small uncharged polar molecules: ex. H2O, glycerol

Question 22

semi-permeable molecules

Answer 22

large uncharged polar molecules: ex. glucose, sucrose

Question 23

low permeable molecules

Answer 23

ions, Na+, Cl-, K+. Ca2+

Question 24

how polar molecules enter cells

Answer 24

facilitated diffusion, involving channel proteins and carrier/transport proteins (in plasma membrane)

Question 25

channel protein structure

Answer 25

membrane proteins that form channels through the plasma membrane, lined with polar (hydrophilic) amino acids, non-polar (hydrophobic) amino acids face the outside of the channel, towards fatty acid tails of lipid molecules

Question 26

Aquaporins

Answer 26

water channel proteins, main ways water moves through membrane

Question 27

ion channels

Answer 27

ion channels are GATED, gates open or close to facilitate the movement of ions, when opened, ions flow down concentration gradient

Question 28

potassium channel

Answer 28

ion channel that allows passage of potassium,

Question 29

transport/carrier proteins

Answer 29

form channels but they are also specifically bind the transported substance, have binding sites, allows transport to be selective

Question 30

transport/channel proteins and selectivity

Answer 30

transport of sugars and amino acids, allow diffusion in both directions, concentration gradient can be maintained by metabolizing the transported substance once it enters the cell ex. glucose metabolized when enters the cell so glucose levels remain low and movement continues

Question 31

active transport

Answer 31

requires the expenditure of energy, moves AGAINST concentrations (from low to high), energy direct or indirectly from ATP hydrolysis

Question 32

direction of active transport

Answer 32

uniport, symport, antiport

Question 33

uniport transporters

Answer 33

move a single type of solute (ex. calcium ions) in one direction against its concentration gradient

Question 34

symport transporters

Answer 34

move two solutes in the same direction, only ONE of which is against its concentration gradient (ex. amino cid transport coupled with sodium ion transport, sodium moves down, amino acids move against)

Question 35

antiport transporters

Answer 35

move two solutes in opposite directions, one into the cell, one out of the cell, both of which are AGAINST their concentration gradients (ex. sodium potassium pump, sodium out, potassium in, each 1 ATP 3 Na+ out and 2 K+ in)

Question 36

sodium transport across membrane

Answer 36

cells use loss of energy from sodium movement through protein to push in K+; if sodium channel is open, sodium goes into cell until equilibrium is reached; inside of cell reaches 15mM then pushes extra sodium out with ATP, while K+ is pushed into cell (opposite direction, against concentration gradient)

Question 37

sodium-potassium pump process

Answer 37

3 sodium ions bind to pump, Na+ binding stimulates phosphorylation (phosphate and ADP) by ATP, this causes protein to change shape and Na+ is expelled, then + binds on extracellular side and triggers release of phosphate group, protein goes back to original shape and 2 K+ are pumped in (cycle repeats!)

Question 38

electrogenic pump (proton pump)

Answer 38

moves ions against an ionic gradient aand generate a voltage difference across the membrane; proton pump causes + or - difference; ACTIVE

Question 39

cotransport

Answer 39

transport mechanism for one ion or molecule can help out another transporter to move and different ion or molecule

Question 40

coupled transport processes

Answer 40

cooperate to facilitate the movement of ions or molecules across membranes, requires energy (ACTIVE), cotransport

Question 41

active transport by concentration gradient

Answer 41

electrogenic pumps can be used to help drive symporters such as the sucrose transporter by maintaining an ionic gradient

Question 42

active transport by concentration gradient examples

Answer 42

sucrose-proton cotransporter; glucose-sodium/potassium pump cotransporter

Question 43

bulk transport across membranes

Answer 43

food or other particle is engulfed by membrane and is put in food vacuole, food particle + extracellular fluid/solutes enter via endocytosis

Question 44

receptor endocytosis

Answer 44

a coated pit and a coated vesicle formed during receptor-mediated endocytosis