lipids Flashcards
why are phospholipids classed as a compound
the fatty acid compound can vary
two ways lipids are diverse
chemically and functionally
explain lipids solubility
mostly insoluble in water, soluble in solvents that have low polarity
list molecules from their decreasing polarity (i.e most polar to non polar)
salts, acids, ketones, Esthers, halogenated, aromatic, aliphatic
name 4 amphipathic molecules
sodium stearate,
sodium p dodecylbenzenesulfonate, hexadecyltrimethylammonium chloride
di(ethylene glycol) dodecyl ether
name a soap
sodium stearate
name a cationic detergent
hexadecyltrimethylammonium chloride
name an anionic detergent
sodium p dodecylbenzenesulfonate
name a nonionic detergent
di (ethyl glycol) dodecyl ether
two types of amphiphiles
single chain and double chain
explain the dietary source of lipids
2% in plants and animals
tiny percent manufatured in the body
95% triacylglyceride (fats, oils, corn, nuts, milk, cheese)
3 lipid structures
simple
compund
derived
what are simple lipids
esters of fatty acids
what are fats
fatty acids and glycerols
what are waxes
long chain fatty acids and log chain alcohols
what are compund lipids
esters of fatty acids and alcoholds that also contain another group
what are derived lipids
composed of hydrocarbon rings and a long hydrocarbon side chain
name 4 common lipids
cholersterol
free fatty acid
triglyceride
phospholipid
draw sphingosine
draw sphingomyelin
what is demyelination
breakdown of myelin sheaths leading to multiple sclerosis
name two C18 fatty acids
octadecanoate
octadenenoate
what acid is octadecanoate
stearate
what acid is octadenenoate
oleate
draw octadecanoate
draew octadecenoate
how many double bonds in octadecanoate
0
how many double bonds in octadecenoate
1
how many double bonds in octadecadienoate
2
how many double bonds in octadecatrienoate
3
3 functions of lipids
- energy supply and storage
- membrane components/surface openings
- signals, messengers, cofactors, pigments
how are lipids energy stores
fatty acids are stored as triacylglycerol
how are triacylglycerols economical
non-polar; doesn’t bind with water
6x more energy than glycogen
how are triacylglycerols efficient
more reduced than proteins and carbons
have a higher caloric yield 9 vs 4 kcal/g
what is step 1 in triacylglycerol synthesis
production of phosphatidate in the ER and outer mitochondrial membrane
what are lipins
phosphotase and acyltransferase are enzymes associated in a complex called triacylglycerol synthetase
6 components of an adipocyte
- mitochondria
- rough ER
- nucleus
- Golgi
- membrane
- fat reserve
4 b - cell functions
- drives fatty acid uptake
- drives glucose uptake
- drives TAG synthesis
- inhibits lipase
3 a - cell functions
- drives fataty acid release by triggering lipase
- inhibits TAG synthesis
- glycerol release
what is step 2 of triacyl glycerol synthesis
hydrolysis of phosphatidate to DAG and acylation to TAG by diglyceride acyl transferase
3 components of phosphatidylserine
- fatty acid
- glycerol
- alcohol
2 categories of membrane lipids
phopholipids and glycolipids
2 physical charachteristics of membrane lipids
polar head group and non polar hydrocarbon tail
why is the dual polarity important
allow membrane lipids to forma beta sheet
5 components of phospholipid synthesis
- glucose
- DHAP
- glycerol
- glucose 3 phosphate
- phosphatidate
- alcohol -> phospholipid
what is DHAP
dihydroxyacetone phosphate
why is DHAP important
- precursor for glycerol backbone
- glycolytic intermediate
step 1 in phospholipid synthesis
activation of phosphitadate with cytidine transport
pyrophosphate is released and must by hydrolysed to drive rxn forward
step 2 in phospholipid synthesis
the hydroxyl group of the alcohol in linked in a phosphodiester bridge
CMP is released
what is CMP
cytidine monophosphate
what is the kennedy pathway
the synthesis of phosphatidyl choline in the liver
explain the second pathway to produce phophatidyl choline in the liver
methylation of phosphatidylethanolamine
which pathway produces phophatidyl choline do novo
the second pathway
how else is choline obtained
from the diet
draw the methylation of phosphatidylethanolamine
how is phosphatidyl inositol constant
stearic acid in C1
arachidon acid in C2
how does phosphatidyl become PIP2
further phosphorylation by 4,5 bisphosphate (becoming an importantt signal transduction molecule)
all phospholipids have a, b, c
a = polar phosphate
b = glycerol
c = non-polar fatty acids
