cell signalling and cell membrane

Question 1

balls like structures of phospholipids

Answer 1

micelles

Question 2

sheet like structures of phospholipids

Answer 2

bilayers

Question 3

fluidity in fluid mosaic model

Answer 3

both phospholipids and proteins can move

Question 4

mosaic in fluid mosaic model

Answer 4

pattern produced by the scattered proteins molecules when cell membrane is viewed from above

Question 5

what to double c-c bonds to do fluidity

Answer 5

unsaturated tails make the membrane more fluid as fatty acid tails are bent and fit together more loosely

Question 6

what happens to fluidity as temp decreases

Answer 6

it decreases as there is less ke and phospholipids move less and pack together

Question 7

cholesterol

Answer 7

acts as fluidity buffer, stops pl packing together when low temps
hydrophobic regions help prevent ions and polar molecules form passing through

Question 8

5 things the gp+gl+pr can be for

Answer 8

receptor molecules
cell to cell recognition
transport proteins
enzymes
cytoskeleton

Question 9

channel proteins

Answer 9

water filled pores
allow charged substances(ion) to diffuse and water
gated
only down conc gradient

Question 10

carrier proteins

Answer 10

flip between 2 shapes
transport up and down conc gradient

Question 11

cell signalling

Answer 11

molecular mechanisms by which cells detect and respond to external stimuli including communication between cells

Question 12

step of cell signalling

Answer 12

1. stimulus causes cell to secret a ligand
   2.ligand is transported to target cell
   3.ligand binds to cell surface receptor on the target cell
2. transduction- ligand causes change of shape of receptor
   5.receptor spans membrane so message is passed to inside of cell
   6.response

Question 13

autocrine signalling

Answer 13

receptors on releasing cells

Question 14

paracrine signalling

Answer 14

receptors on adjacent cell

Question 15

endocrine signalling

Answer 15

signals have to travel through blood

Question 16

ligand

Answer 16

a biological molecules which binds to another molecule like a cell surface membrane receptor during cell signalling

Question 17

transduction

Answer 17

process of converting a signal from one method of transmission to another

Question 18

4 factors affecting diffusion

Answer 18

nature of molecules
surface area
temp
steepness of conc gradient

Question 19

what to channel p carry

Answer 19

only ions

Question 20

aquaporins

Answer 20

type of channel protein for water as when water diffuses normally it is slow

Question 21

what to carrier p carry

Answer 21

glucose, amino acids, nucleotides, sugar

Question 22

what are channel p

Answer 22

hydrophilic pores in cell membrane
only down conc gradient

Question 23

what are carrier p

Answer 23

integral proteins up and down conc gradient

Question 24

water potential

Answer 24

tendency of water to move from one place to another

Question 25

wp depends on

Answer 25

conc of sol
pressure applied

Question 26

endocytosis

Answer 26

the bulk movement of liquids or solids into a cell by the unfolding cell surface membrane to form vesicles containing the substance
requires app

Question 27

exocytosis

Answer 27

the bulk movement of liquids or solids out of a cell by the fusion of vesicles containing the substance with the cell surface membrane
active process requires atp

Question 28

phagocytosis

Answer 28

bulk uptake of solid material. phagocytes specialise in this

Question 29

bulk uptake of liquid

Answer 29

pinocytosis/micropinicytosis