1.5 Lipids Flashcards
what are some lipid characteristics?
- contain carbon, hydrogen, oxygen
- proportion of oxygen to carbon and hydrogen is smaller than in carbs
- insoluble in water
- soluble in water e.g. alcohols, acetone
what are the main groups of lipids?
- triglyceride- fats and oils
- phospholipids
what are roles of lipids
phospholipids in cell membrane
=flexibility, transfer of lipid soluble substances
what are roles of lipids?/phospholipids
- source of energy
- waterproofing
- insulation
- protection
how are lipids a good SOURCE OF ENERGY?
- when oxidised provides twice as much energy as the same amount of carbohydrate
- releases valuable water too
how are lipids a good at WATERPROOFING?
- lipids=insoluble in water
- plants+insects: waxy lipid cuticles
- mammals: oily secretion from sebaceous glands in skin
how are lipids a good at INSULATION?
-fats are slow conductors of heat
=retain heat when stored beneath body surface
-act as electrical insulators in myelin sheath around nerve cells
how are lipids a good at PROTECTION?
-fats stored around delicate organs e.g. the kidney
what state are different triglycerides at room temperature? (10-20)
- fats=solid
- oils= liquid
what are triglycerides made from?
3 fatty acids
1 glycerol
how are triglycerides bonded together?
ester bond
condensation reaction
what are the products of the hydrolysis of triglyceride?
3 fatty acids
1 glycerol
what is the word equation for a triglyceride?
glycerol + 3 fatty acids = triglyceride + 3 water
what causes differences in properties of fats and oils?
fatty acids can vary
how many different fatty acid tyoes are there?
over 70
