Biological membranes

Question 1

Phospholipids

Answer 1

primary components of cell membranes

amphipathic (hydrophobic tail, hydrophilic head)

Question 2

phospholipid tails

Answer 2

fatty acids that are hydrophobic, saturated and unsaturated

Question 3

PLs

Answer 3

have a hydrophilic head with a phosphate moiety and a hydrophobic tail that is made from fatty acids

Question 4

2 kinds of PLs

Answer 4

glycerophospholipids and sphinolipids

Question 5

glycerophospholipids

Answer 5

glycerol backbone with two estrafied fatty acids and a phosphate group. the phosphate group can be estrafied to amino or sugar alcohol groups to produce other PLs

i. phosphtidylcholine
ii. phosphatidyl serine
iii. phosphatidylinositol

Question 6

Sphingolipids

Answer 6

sphingosine backbone

sphingosine plus a phosphorylcholine make spingomyelin, most common SL present in outer leaflet

Question 7

what are the three main groups that can estrify a phosphate group on a glycerophospholipid?

Answer 7

1. choline
2. serine
3. inositol

Question 8

a sphingosine backbone (Define), a fatty acid, a phosphate attached to a choline group

Answer 8

sphingosine = glycerol with a hydrocarbon tail @ C3 and an amine group @ C2 
PO4+chline = myelin 

Sphingosine, FA, PO4-Choline = sphingomyelin

Question 9

sphingosine

Answer 9

glycerol with a hydrocarbon attached to it and an amino group @ 2nd carbon

hydroxyl groups at 1 and 3

Question 10

Glycolipids

what are they made from and where are they found

Answer 10

have a sphingosine backbone and contain a carbohydrate (oligosaccharide) residue. found in outer leaflet of the lipid bilayer

Question 11

Cholesterol

Answer 11

embedded in lipid bilayer
steroid nucleus with a hydroxyl group and a hydrocarbon side chain. side chain interacts with hydrophobic tails of membrane lipids

Question 12

Phospholipids found in the outer membrane

Answer 12

phosphatidylcholine
sphingomyelin
glycolipids

Question 13

Phospholipids found in the inner sheet

Answer 13

Phosphatidylinositol
Phosphatidylserine
Phosphatidylethanolamine

Question 14

Membrane proteins

integral membrane proteins

how are they defined

Answer 14

defined by how they are associated with the PL bilayer

they are firmly embedded in the membrane and stabilized by hydrophobic interactions

Question 15

transmembrane proteins

what they are and what this category includes

Answer 15

integral membrane proteins that span the entire lipid bilayer and interact with both internal and external envrionemtn

includes transporters, ion channels, and receptors

Question 16

integral monotropic proteins

Answer 16

integral membrane protein

firmly attached to one sheet of membrane

Question 17

Peripheral proteins

Answer 17

loosely bound to the membrane through electrostatic interactions with lipids or proteins

Question 18

Lipid anchored proteins

Answer 18

tethered to membranes via a covalent attachment to a lipid molecule

Question 19

four integral proteins and their classification

Answer 19

monotropic (span membrane but attached firmly to just one leaflet)
bitopic I and II
polytopic

Question 20

associated membrane proteins

Answer 20

Protein associated, Acyl anchored, phospholipid associated

Question 21

Polytopic proteins

Answer 21

span membrane five times

Question 22

Monotopic

Answer 22

span membrane once

Question 23

bitopic type I

Answer 23

single membrane spanning have an internal COO- and an external NH3 group

Question 24

bitopic type II

Answer 24

single membrane spanning have an internal NH3 group and an external COO- group

Question 25

Oligosaccharide molecules

Answer 25

covalently bound to proteins and lipids facing extracellular side

Question 26

Glycocalyx has 3 key functions

Answer 26

1. protection 2. cell adhesion 3. cell identification

Question 27

Glycocalyx has 3 key functions Protection

Answer 27

Protection protects membrane components from premature enzymatic degradation

Question 28

Glycocalyx has 3 key functions Cell adhesion

Answer 28

enables cell to make more stable contacts with other cells , important during tissue formation and fertilization

Question 29

Glycocalyx has 3 key functions Cell identification

Answer 29

allows the body to differentiate its own healthy cells from foreign of diseased cells. very important in red blood cells

Question 30

Phosphatidylserine Correlation box

Answer 30

in healthy cells, phosphatidylserine is displayed in the inner leaflet. during apoptosis, it's displayed on the extracellular side, serving as a biomarker for phagocytes

Question 31

Niemann-Pick Disease

Answer 31

caused by a deficiency in the activity of acid-sphingomyleinase (A-SMase), a lysosomal enzyme ``` Type A (most severe): less than 1% of A-SMase Type B (less severe): 10% A-SMase Type C (least severe): caused by defects in cholesterol transport. Accumulation of cholesterol in cells causes a secondary reduction in A-SMase activity ``` sphingomyelin accumulates in the lysosomes of cells in the CNS, liver, spleen and bone marrow causes enlargement of the liver and spleen (hepatosplenomegaly) and neurological damage (mental retardation, seizures, ataxia and spasticity) patients have cherry red macula

Question 32

Blood group O monomer structure and antibodies present

Answer 32

Gal--GlcNAc--Gal--Fuc anti-A anti-B antigen group: H

Question 33

Blood group A monomer structure and antibodies present

Answer 33

Gal-GlcNAc-Gal-Fuc--GalNAc anti-B antigen group: A

Question 34

Blood group B monomer structure and antibodies present

Answer 34

Gal-GlcNAc--Gal--Fuc--Gal anti-A antigen group: B

Question 35

Blood group A/B monomer structure and antibodies present

Answer 35

Gal-GlcNAc-Gal-Fuc--GalNAc Gal-GlcNAc--Gal--Fuc--Gal no anti-bodies antigen group: AB

Question 36

universal donor

Answer 36

O, has no antigen to attack. can only accept blood from other O types because of antibodies agains A and B

Question 37

universal acceptor

Answer 37

AB, has no antibodies against any antigens. can receive from O, A, B, AB

Question 38

Rh factor

Answer 38

there are many Rh antigens but term applied specifically to D antigen Rh+ expressed D antigen Rh- to not express D antigen

Question 39

Rh antigen is

Answer 39

autosomal dominant

Question 40

Rh+/Rh- mother/child

Answer 40

child has to be Rh+, and mother has to be Rh-

Question 41

Erythroblastosis fetalis occurs when

Answer 41

the mother's antibodies attack the child causing premature abortion