Nutritional Properties of Lipids Flashcards
define macronutrient
a type of food (e.g. fat, protein, carbohydrate) required in large amounts in the diet.
what are the functions of lipids
energy (FAs)
fat storage (TGs)
hormones (sterols)
phospholipids (cell membrane)
what are the biological functions of lipids
energy
structural integrity
signalling
Lipid DRVs?
none set as not an essential nutrient
dietary sources of saturated fat
coconut
meat
cheese
dietary sources of unsaturated fat
MUFAs - olives, nuts, vegetable oil PUFAs - cereals, fish Trans unsat - meat, dairy, processed foods
examples of unsaturated FAs
monounsaturated
- oleic
- C18:1
polyunsaturated
- linoleic C18:2
- linolenic C18:3
which tissues use fat for energy?
skeletal
heart
functions of cholesterol
membrane fluidity
bile salts
steroids- androgens/ estrogen, mineralocorticoid, glucocorticoids
where does fatty acid metabolism occur
the mitochondria
- FA to acetyl CoA by beta oxidation
the cytosol
- FAs are synthesised from acetyl CoA
cartinine
- transports long FA to the mitochondria to be oxidised to release energy
examples of fat soluble vitamins
A, D, E, K
consequences of excessive lipid intake
obesity diabetes CV disease cancer hyperlipidaemia
what are essential FAs?
FAs required in the diet
- N-3 and N-6 cannot be synthesised by humans due to a lack of desaturase enzymes, therefore we require them from dietary sources
What are essential FAs needed for?
visual development
regulating cell membrane structure
synaptic function
what are eicosanoids needed for?
cell signalling
examples of eicosanoids
prostaglandins
prostacyclins
thromboxjnes
leukotrienes
what are eicosanoids needed for?
cell signalling
inflammation immunity
where do eicosanoids come from?
they are synthesised from essential FAs in lipid bilayers
what are examples of the N-3 essential FAs?
alpha-linolenic
eicosapentaenoic acid
docosahexaenoic acid
N-6
linoleic
arachidonic
what is another name for N-3 and N-6 FAs?
omega fatty acids
dietary sources of N-3 FAs?
fish oils
flax seed oil
rape seed oil
linseed oil
dietary sources of N-6 FAs?
vegetable oil
