Core component 1 -Lipids Flashcards
What makes up a triglyceride ?
One glycerol molecule and 3 fatty acids
Describe the reaction of the formation of a triglyceride
The fatty acids join the glycerol in a condensation reaction where ester bonds are formed between the glycerol and fatty acids and three molecules of water are eliminated
Why do phospgolipids have one end which is polar and one end which isn’t polar?
One end of the phospholipid has lots of oxygen atoms and one end has no oxygen atoms.
Describe features of a phospholipid relative to water?
The tail of the phospholipid is non-polar and therefore does not interact with water however the phosphate head is polar and therefore does interact with water.
What does saturated mean?
When the hydrocarbon chain only has single carbon-carbon bonds.
What monounsaturated and polyunsaturated mean?
Mono - contains one double bond
Poly - contains two or more double bonds
What are the roles of phospholipids?
1) In biological membranes
2) Electrical insulation - the myelin sheath that surrounds axons of nerve cells
What are the roles of triglycerides?
1) Energy storage- lipids contain more C-C bonds than carbohydrates
2) Thermal insulation - when stored under the skin lipids insulate against heat loss or heat gain
Protection - fat is often stored around delicate internal organs to protect them
Metabolic water - triglycerides produce a lot of metabolic water when oxidised
What are the roles of waxes?
Waterproofing - such as in the insect exoskeleton and on the cuticle of plants
How do you test if a sample contains lipids?
The sample is mixed with ethanol and then is shaken with an equal volume of distilled water. If a lipid is present a cloudy, white emulsion is formed.
What happens if a diet is high in saturated fats?
Contributory factor to heart disease. LDL level raises. Antheroma increasingly deposited in the coronary arteries, restricting blood flow and therefore oxygen delivery to the heart.
What happens if a diet is high in unsaturated fats?
The body makes more HDL. This carries harmful fats away to the liver for disposal.
Describe the process when a triglyceride molecule is broken down
Water is added to break ester bonds in a hydrolysis reaction.
What is the general formula for an unsaturated fatty acid
CnH2nO2
