Chp 5—Lipids & Biological Membranes

Question 1

6 biochemical functions of lipids

Answer 1

1. structure of plasma membrane
2. energy storage
3. protection
4. cell signalling
5. cofactors
6. flavor & fragrance

Question 2

monomer of lipids

Answer 2

fatty acids

Question 3

2 components of FAs

Answer 3

carboxylic acid
hydrocarbon chain

Question 4

2 types of FAs

Answer 4

saturared & unsaturated

Question 5

delta nomenclature

M:N(𝚫^a,b….)

Answer 5

M = number of carbons
N = number of double bonds
a, b…. = position of double bonds

M:N(𝚫^a,b….)

Question 6

for delta nomenclature, we number from…

Answer 6

the COOH

Question 7

components of a triglyceride

Answer 7

3 FAs
glycerol backbone

Question 8

how are FAs joined to glycerol?

Answer 8

esterification rxn

Question 9

Answer 9

glycerol

Question 10

function of triglycerides

Answer 10

energy storage in adipose

Question 11

simple triaglycerol

Answer 11

3 chains are identical

Question 12

complex triaglycerol

Answer 12

3 side chains are different

Question 13

components of wax
joined by?

Answer 13

FA
long alcohol chain

esterification rxn

Question 14

Answer 14

wax

Question 15

function of wax

Answer 15

protection and moisture retention

Question 16

mp of waxes

Answer 16

60-100 C

Question 17

components of soap
joined by?

Answer 17

triglyceride
aqueous alkali (NaOH, KOH)

saponification rxn

Question 18

micelle

Answer 18

aggregation of soap molecules around dirt

Question 19

function of eicosanoids

Answer 19

autocrine & short-range signalling molecules

Question 20

Answer 20

eicosanoid

Question 21

eicosanoid SM

Answer 21

arachidonic acid

Question 22

basic eicosanoid structure

Answer 22

5-mem ring with two acid tails, and many possible R groups

Question 23

components of phospholipid

Answer 23

phospho “head”
1 or 2 FA tails

Question 24

components of glycerophospholipid

Answer 24

2 FA tails + glycerol + phosphate + R group

Question 25

components of sphingolipid

Answer 25

1 FA tail + sphingosine backbone, including nitrogen + R groups

Question 26

Answer 26

glycerophospholipid

Question 27

Answer 27

sphingolipid

Question 28

function of sphingolipids

Answer 28

cell recognition and signal transduction

Question 29

glycolipid

Answer 29

sugar residue + sphingolipid

Question 30

basic unit of terpenes/terpenoids

Answer 30

isoprene

Question 31

function of terpenes/terpenoids

Answer 31

fragrance, flavor, color

Question 32

function of sterols

Answer 32

component of cell membrane; controls consistency

Question 33

function of steroids

Answer 33

body-wide signalling hormones

Question 34

basic structure of sterol/steroid

Answer 34

3 6-mem rings + 1 5-mem ring

Question 35

lipid vitamins

Answer 35

A D E K

Question 36

5 components of membrane

Answer 36

glycerophospholipids sphingolipids sterols proteins carbs

Question 37

membrane held together by...

Answer 37

hydrophobic interactions

Question 38

4 main points of fluid mosaic model

Answer 38

- phospholipids have **free lateral movement**, but not transverse movement - phospholipids can move **2nm/second** - double bonds in phospholipid tails **increase fluidity** because they decrease steric space - majority of mass is from mosaic of **proteins**

Question 39

2 main types of proteins in membrane

Answer 39

transmembrane/integral proteins peripheral proteins

Question 40

3 common types of transmembrane proteins

Answer 40

alpha helices helical bundles beta barrels

Question 41

peripheral proteins may be ____proteins

Answer 41

lipoproteins

Question 42

lipid raft

Answer 42

stable domain of proteins which must be in proximity to work together, floating as a unit in the membrane

Question 43

how is a lipid raft held together

Answer 43

sterols in the membrane make tighter associations between unsaturated tails

Question 44

2 aspects of membrane function

Answer 44

selective barrier communication within and among cells

Question 45

4 steps of primary messenger pathway

Answer 45

1. bind to surface receptor 2. conformational change of receptor 3. dimerization/oligomerization event (might be phosphorylation) 4. biochemical pathway activated

Question 46

3 steps of secondary messenger pathway

Answer 46

1. amplification—concentration increases following primary messenger 2. bind to internal cellular target 3. biochemical pathways are regulated

Question 47

which second messengers are NOT lipid-derived?

Answer 47

cAMP Ca2+ IP3 (sugar part of a former lipid)