lipids Flashcards
what are lipids
heterogeneous organic molecules
very insoluble
hydrophobic
what are lipids functions
stores of energy structural elements of membranes enzyme cofactors hormones vitamins signalling molecules
what are the lipid vitamins
ADEK
what are the main classes of lipids
fatty acids triacylglycerol (adipose tissue) phospholipids glycolipid (lipid with carb attached) steroids
what are fatty acids
hydrocarbons chains with a carboxylic acid group
saturated or unsaturated
how do we name fatty acid
18: 0 - 18 carbons no double bond
18: 1 - 18 carbons - 1 double bond
saturated fatty acid has…
no kinks
what are the 4 categories of Fatty acids
essential
good fats
bad fats
really bad fats
what are essential fatty acids
linoleic and alpha linoleic
get from plants as cant synthesis fats longer than 6C
what are good fats
good in cardiovascular terms
high in polyUNSATURATED fatty acids (vegetable oils)
what are bad fats
high in SATTURATED fatty acids
BEEF
stearic acid
what are really bad fats
MAN MADE
Trans fatty acids
come form hydrogenation of vegetable oils - margarine
when can bad (saturated) fats sometimes be good
saturated fats play an important part in myelination
what is omega 3
derived from linoleic acid
lowers plasma cholesterol
lowers TAG
what is TAG (triacylglycerol’s)
a ESTER of fatty acids and glycerol
water insoluble and collect into droplets
dietary fuel and adipose tissue insulation
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what are phospholipids
made of glycerol, two fatty acids and a phosphate group - has an ester link
are also amphipathic
what does amphipathic mean
has a phosphate head which is hydrophilic and hydrophobic tales (2 FAs)
where are most lipids digeste
the small intestine
how are TAG molecules digested
small intestine - pancreatic enzymes
emulsification by bile salts and peristalsis
what dose digested TAG become and by what enzyme
it becomes a monoacylglycerol and two fatty acids
what do bile salts act as
biological detergent
and creates micelles
what is produced when cholesterol esters are digested
broken down into cholesterol and a free fatty acid
what do phospholipids become and how
they are hydrolysed to become a Fatty acid and a lysophospholipid
how are lipids taken up
by micro villi
DIFFUSION
short and medium fatty acids diffuse across without micelles
long chain FA need a micelle created by bile salts
what forms a micelle
bile salts
what happens if pancreatic lipase is inhibited or you can uptake fats
get steatorrhea
oily and smell like shit
excess lipids