lecture 3

Question 1

what do proteins do

Answer 1

carry our cellular activities

Question 2

do all polypeptides have a common backbone

Answer 2

yes

Question 3

can a protein have more than 1 function? if so, what causes this

Answer 3

yes they can
different domains cause it

Question 4

what Is a ribosome made of

Answer 4

proteins and RNA molecules

Question 5

what separates the cell from the environment

Answer 5

plasma membrane

Question 6

what is the membrane also called

Answer 6

fluid mosaic model

Question 7

what are 3 three types of membrane lipids

Answer 7

phosphoglycerides
sphingolipids
cholesterol

Question 8

are membrane lipids amphipathic

Answer 8

yes

Question 9

what joins the fatty acids + phosphate group In phospholipids

Answer 9

alcohol residue

Question 10

what is the alcohol residue in phosphoglyceride

Answer 10

glycerol

Question 11

whats the composition of phospholipids

Answer 11

fatty acids + phosphate group joined by an alcohol residue

Question 12

what are sphingolipids made with

Answer 12

sphingosine

Question 13

whats the basic structural unit of all sphingolipids `

Answer 13

ceramide

Question 14

whats the myelin sheath of nerve cell axons made of

Answer 14

sphingomyelin

Question 15

what are A Cerebroside and A Ganglioside

Answer 15

glycolipids

Question 16

what doo glycolipids have attached to them

Answer 16

a sugar

Question 17

what are the 2 glycolipids that she has in the notes

Answer 17

cerebroside and ganglioside

Question 18

what is cholesterol ?

Answer 18

a sterol

Question 19

what is unique about cholesterol

Answer 19

it is small and less amphipathic than most membrane lipids

Question 20

how much of the lipid membrane does cholesterol make up

Answer 20

50%

Question 21

what makes top 50% of the lipids in animal membranes

Answer 21

cholesterol

Question 22

whats the structure of cholesterol

Answer 22

flat and rigid rings

Question 23

what does cholesterol impact

Answer 23

how tightly lipids are packed together in the membrane

Question 24

what end of cholesterol faces the external surface of the bilayer

Answer 24

their small hydrophilic end

Question 25

is cholesterol evenly dispersed within the membrane sides

Answer 25

yes

Question 26

is there an asymmetric distribution of phospholipids

Answer 26

yes

Question 27

where does membrane assembly begin

Answer 27

the ER

Question 28

where are the enzymes that form the membrane found

Answer 28

in the cytoplasmic region of the ER

Question 29

where does the synthesis of phospholipids happen

Answer 29

the cytosolic side of the ER

Question 30

what does a scramblase do

Answer 30

scrambles phospholipids to have even numbers on each side

Question 31

where is scramblase found

Answer 31

cytoplasmic region of the ER

Question 32

is scramblase specific

Answer 32

no

Question 33

what is the source of membrane leaflet asymmetry

Answer 33

Golgi apparatus

Question 34

what do flippases do

Answer 34

transfers SPECIFIC phospholipids between monolayers

Question 35

where is a flippase enzyme found

Answer 35

the Golgi apparatus

Question 36

can the lipid bilayer self assemble

Answer 36

yes

Question 37

what has been proven invaluable in membrane research

Answer 37

liposomes

Question 38

what are lysosomes

Answer 38

vesicles that can deliver stuff such as drugs, DNA, or membrane proteins

Question 39

what are membrane carbohydrates

Answer 39

sugar content of the eukaryotic cell membrane

Question 40

where are membrane carbohydrates located on the membrane

Answer 40

extracellularly

Question 41

what do membrane carbohydrates do

Answer 41

play an important role in cellular interactions of cell with its environment

Question 42

whats glycosylation

Answer 42

where a sugar is attached to a protein or lipid

Question 43

what bond holds a lipid and a sugar together to forma glycolipid

Answer 43

covalent glycosidic bond

Question 44

what do glycolipids play a role in

Answer 44

determining/expressing blood type

Question 45

how does A blood type express with glycolipids

Answer 45

an enzyme adds N-acetylgalatosamine to chain terminus

Question 46

how does B blood type express with glycolipids

Answer 46

an enzyme adds galactose to the chain terminus

Question 47

how does O blood type express with glycolipids

Answer 47

O lacks enzymes to attach either terminal sugar

Question 48

how does AB blood type express with glycolipids

Answer 48

both enzymes attach both sugar

Question 49

what a glycoprotein

Answer 49

a sugar attached to an amino acid

Question 50

what are the two types of linkages for glycoproteins

Answer 50

N linkages (nitrogen) O linkages (o of OH)

Question 51

what are the 2 types of O linkages

Answer 51

serine threonine (hydroxyl groups)

Question 52

what are the two types of N linkages

Answer 52

Asparagine Arginine