Lipids Flashcards
lipids hydro - phobic or philic
hydrophobic
how do they make themselves more soluble to move around the body
often bond to a protein - lipoprotein
main form of dietary fat
triglycerides
what can be solid/liquid at room temp
includes fats and oils
is a concentrated form of chemical energy
triglycerides
structure of a triglyceride
1 glycerol
3 fatty acids
joined by ester bonds
what reaction breaks down triglycerides
hydrolysis
4 functions triglycerides
source of energy (less efficient than carbs)
storage of excess calorific intake
insulation
protection of body parts
state of saturated fat at room temp
solid - straight molecules (can tightly pack)
state of monounsaturated fat at room temp
liquid - one bend so cannot pack
state of polyunsaturated fat at room temp
liquid - v bent molecules
how are fatty acids named
according to closest double bond to OMEGA carbon
cis or trans fats more common in nature
cis
different in molecular structure - cis and trans
cis bent, trans straight
2 ways that trans fats can be formed
cis fats can turn to trans by heating at high temps
- hydrogenation processes in making margarine/processed foods
what type of fatty acids are EFAs
polyunsaturated
cannot be made in the body
name omega 6 family of fatty acids
LA
GLA
AA
eicosanoids
LA - long name and source
LINOLEIC ACID
veg oils, seeds, nuts
GLA long name & source
GAMMA-LINOLENIC ACID
borage/evening primrose oil/converted from LA
AA long name & source
ARACHIDONIC ACID
meat/converted from GLA
name family of omega 6 fatty acids
LNA
EPA
DPA
Eicosanoids
long name & source LNA
ALPHA-LINOLENIC ACID
green leafy veg, flax, walnuts
long name & source EPA
EICOSAPENTAENOIC ACID
converted from LNA/fish oil
long name & source DPA
DOCOSAHEXAENOIC ACID
converted from EPA/fish oil
can body convert form of one EFA to another in same family
yes, cannot make from scratch
what can happen when EFAs are exposed to light, heat and oxygen
become free radicals
how should you store EFAs
in dark glass bottle in fridge
never cook with
11 functions EFAs
fluidity/chemical activity cell membranes
synthesis prostaglandins
regulate 02 use, electron transportation, energy production
help form haemoglobin
support production of digestive enzymes
lubricate joints
help transport cholesterol in blood
help generate electrical currents, keep heart regular
help balance immune system - prevent allergies
ensure proper nerve transmission
bone formation/repair
definition of lipoprotein
fat molecule joined to a protein so lipid can move around blood stream
where are lipoproteins synthesised
liver
4 types lipoproteins
chylomicrons
VLDL
LDL
HDL
role of chylomicrons
carry triglycerides from intestines to
liver, skeletal muscles, adipose tissue
role of very low density lipoproteins
carry newly synthesised triglycerides from liver to
adipose tissue
role of low density lipoproteins
carry cholesterol from liver to
cells of body (known as bad cholesterol)
role of high density lipoproteins
collect cholesterol from tissues and returns it to
liver
structure of phospholipid
1 glycerol
2 fatty acid chains
phospholipids are amphiphatic, this means
soluble 1 side, insoluble on the other
3 ex steroids
cholesterol
oestrogen
testosterone
steroids formed from
cholesterol
2 stages of fat digestion
in duodenum bile salts released to emulsify
pancreatic lipase breaks down triglycerides into fatty acids and glycerols
most important fat digesting enzyme
pancreatic lipase
what happens at end of fat digestion
end products dissolve in membrane lining of small intestine helped by intestinal lipase
then goes into lacteals in villi
