cell membranes

Question 1

how much fatty acids do triglycerides have

Answer 1

3 bonded to one molecule of glycerol

Question 2

describe the polarity in a triglyceride

Answer 2

non polar which makes them hydrophobic and insoluble to water

Question 3

phospholipid structure -molecular

Answer 3

two fatty acid bonded with one glycerol via esta bond and a phosphate group

Question 4

polarity of a fatty acid

Answer 4

non polar hydrophobic

Question 5

polarity of phosphate group

Answer 5

charged which means it is polar and hydrophilic

Question 6

general structure of a phospholipid

Answer 6

non polar hydrophobic tails and a hydrophilic polar head

Question 7

how are phospholipids arranged with water

Answer 7

the hydrophilic heads interact with the water but the fatty acid are burried in the center away from water -phospholipid bi layer

Question 8

membrane functions

Answer 8

act as barriers, between the internal content of the cell and the external environment
2.or between the contents of an organelle and the cytoplasm
3, chemical reactions
4. cell signalling

Question 9

hydrophobic center means that

Answer 9

hydrophobic molecules can easily pass through
however prevents hydrophilic water soluble molecules from easily passing through
things with a charge cant easily pass through the non polar region of the membranes

Question 10

why is water an exception even when its polar

Answer 10

it is extremely small

Question 11

what other things in the cell surface membranes

Answer 11

protein’s and cholesterol

Question 12

cholesterol hydrophilic group is found where

Answer 12

contains a hydrophilic group at one end this group can attract the polar head group on the phospholipid molecules
the rest of the cholesterol is nonm pollar and can attract the fatty acids in the phospholipids

Question 13

cholesterols function in phospholipid

Answer 13

it increases the strength of the cell surface membrane and makes it more stable and less likely to be damaged
reduces the sideways movement of phospholipids
it controls the fluidity. helps the membrane from becoming too fluid in warm conditions
-helps reduces the movement of water soluble molecules across the cell surface membrane

Question 14

fluid mosaic model

Answer 14

fluid-the phospholipid molecules can move around each layer - flexible and change shape
mosaic because its studded with proteins

Question 15

what two categorises can membrane proteins be categorised into

Answer 15

-intrinsic or extrinsic proteins

Question 16

-intrinsic proteins

Answer 16

are fully embedded in the membrane from omen side to the other

Question 17

hydrophobic amino acids in intrinsic proteins

Answer 17

because they pass right through the bilayer the inrisc proteins have hydrophobic amino acids on the outside surface and can interact with the fatty acids in the bi layer

Question 18

what are two types of intrinsic proteins

Answer 18

carrier proteins and protein channel

Question 19

protein channel

Answer 19

the chanel runs through the center lined with hydrophilic amino acid and filled with water molecules

Question 20

what do protein channels allow through

Answer 20

water soluble molecules and ions to diffuse through

Question 21

carrier proteins

Answer 21

can change shape or position to transfer molecules or ions from one side of the membrane to the other

Question 22

extrinsic proteins location

Answer 22

do not span the membrane found on one side or the other

Question 23

extrinsic protein role

Answer 23

-structural role other acts as enzymes and some are receptors for hormones

Question 24

whats a glycoprotein

Answer 24

is a carbohydrate attached to membrane proteins

Question 25

function of glycoproteins

Answer 25

allow cells to attach to each other
immune system: presenting antigens to t cells
receptors for hormones

Question 26

carbohydrase attached to phospholipid molecules

Answer 26

glycolipids

Question 27

glycolipid function

Answer 27

when cells come in contract with one ecohotel

act as antigens