Nutritional Properties of Lipids Flashcards
What is fats primary role?
As a source of energy
What are the functions of lipids?
Source of energy
Storage (triglycerides store forms of fat)
Bilayers
Sterols
What affect do saturated fats have on fluidity of membranes?
Reduce fluidity
What affect do unsaturated fats have on fluidity of membranes?
Increases fluidity
What affect do long chain fatty acids have on fluidity of membranes?
Reduce fluidity
What affect do short chain fatty acids have on fluidity of membranes?
Increase fluidity
What affect does cholesterol have on membranes?
Regulates fluidity by preventing crystallisation but blocking large motions of acyl chain
What are the functions of cholesterol?
Synthesis of bile salts
Synthesis of hormones
Where does the metabolism of fatty acids occur?
In the mitochondria
What must fatty acids be bound to in order to enter the mitochondria?
Carnitine
How does metabolism of fatty acids generate energy?
Via beta oxidation
Why is it essential that omega 3 and 6 fatty acids are obtained in the diet?
Because the body cannot synthesis these fatty acids due to the lack of the enzyme desaturase
What is a source of omega 3 fatty acids?
Fish oils
What is a source of omega 6 fatty acids?
Vegetable oils
What are omega 3 and 6 fatty acids involved in?
Regulating membrane structure
What are omega 3 and omega 6 fatty acids a precursor for?
Eicosanoids = signalling molecules involved in immunity and inflammation
Name two foods high in saturates.
Meat products
Coconut
Name three foods high in monosaturates.
Olives
Vegetable oils
Nuts
Name three foods high in polysaturates.
Cereals
Fish
Plant oils
Name three foods high in trans unsaturated fatty acids.
Meat and dairy (low) Processed foods (high) Spreading fats (high)
What foods is fat mainly obtained by?
Meat products and cereal products
What form is fat mainly obtained in?
Triglycerides
The rest is in phospholipids and cholesterol which have fat soluble vitamins associated with the,
What are the health effects of excessive fat intake?
Hyperlipidemia = high lipid blood levels Cardiovascular disease Obesity diabetes mellitus Cancer = breast, colon and prostate
Why are there no DRVs for fats?
Because they are not essential nutrients (other than omega 3 and omega 6 fatty acids)
What are used instead of DRVs for fat?
EARs
What is the recommendation for percentage energy intake in the form of fat?
33-34%
