Lecture 8: Lipids Flashcards
What are the 4 main lipid families
Triacylglycerols/triglicerides
Glycerophospholilids
Sphingolipids
Isoprenoids
Out of the 4, which are amphipathic
glyceophospholioida
Sphingolipids
Why are isoprenoids diff fromm others
Doesn’t have a fatty acid chain as part of its component
What is name given to carbon that is furthest from the carboxyl carbon in a fatty acid (the one at the end)
omega
What type of double bond exists in natural monounsaturated FAs
cis double bond
Which introduces a kink in the chain
How come tricylglycerols are neutral
no acid based properties cuz
All hydroxyls in the glycerol are fully esterified
Triacylglyecerol structure
glycerol
3 fatty acids
Vry hydrophobic
What is the more abundant memb lipid
glycerophospholipids
What happens to the third hydroxyl group in glycerol in glycerophospholipid
Phosphate group gets esterified onto it
This group then gets further esterified to a polar group
How is the fatty acid linked differently in a sphingolipid
is amide linked
How many hydrophobic tails does sphingolipid have
2
1 fatty acid and then the other long thing
Sphingosine with nothing extra
ceramide
Sphingosine with phosphphocholine/ethanolamine attached
sphingomyelin
The most similar to a glycocerophospholipid
Sphingosine with simple sugar attached
Cerebroside
Sphingosine with complex oligosaccharide attached
ganglioside
What is isoprenoids
All derived from isoprene
Which is a 5 carbon isoprene
What is the shortest isoprenoid
C10
Essential oil components
How many carbon is the vit E precursor
c20
What is C30 isoprenoid
steroids
Structure of steroids
4 ring system
what is cholesterol a precursor to
steroid hormones e.g. Oestrogen
Bile acids- emulsify dietary fats
What makes cholesterol so unflexible
Fused ring system
How does cholesterol act as a buffer
increases fluidity at low temp
Decreases at low temp
What is the distribution of sphingolipids and glycerophospholipids
Outer has more sphingolipid
Cystolic leaflet has more glycerophospholipids
What types of lipid fluidity is there
lateral diffusion = v fast
transverse diffusion = very slow
What are the 3 classes of memb proteins
- integral
- peripheral
- lipid anchored
What 2 ways can memb proteins be interated into memb
memb spanning alpha helices
or
beta bsrrel fold - exterior is hydrophobic and interior usually filled with water
what ways can peripheral memb proteins interact with the memb
charge-charge or hydrogen bonding
either with the integrated proteins or with the polar heads of memb lipids
how can serine or cytosine be anchored into the lipid membrane
ester/thioester bond from the AA to a fatty acyl group
what 3 types of bonds can be formed between AAs in proteins and the lipid memb (on cytosolic leaflet side)
- ester/thoiester
- amide
- thioether
how can a protein be anchored onto glycosykohiskjarhgaerlg idek (GPI)
via its C-terminus
this is on outer leaflet of memb
why are passive tranporters e.g. carriers/permeases slower than memb channels
cuz requires conformational change
what are the 2 types of active transport
primary = direct source e.g. ATP, light, electron transport
secondary = ion conc. gradient
