Lipids Flashcards
What are triglycerides also known as?
Fats and oils.
What are triglycerides made up of?
Three fatty acids and one glycerol molecule.
By what type of reaction does a fatty acid react with a glycerol molecule?
Condensation reaction
Is a lipid/triglyceride a polymer?
NO
What do all fatty acids have in common?
A COOH at the end of the tail.
Which groups are reacting in the condensation reaction between glycerol and fatty acids?
The alcohol (OH) group of glycerol with the acid (COOH) of the fatty acid to form water.
Mention three properties of lipids.
They are insoluble, they can be saturated or unsaturated and they contain C, H and O only.
What does hydrophobic mean?
Not liking water.
Why are fatty acids nonpolar?
Because they have an even distribution of charge.
Why are water molecules polar?
Because they have an even distribution of charge.
Why are triglycerides hydrophobic?
because they are not attracted to the polar water molecules.
What are unsaturated fats?
When they have one or more carbon-carbon double bond.
What properties does an unsaturated fatty acid give to the triglyceride?
It causes the fatty acid to bend at the double bond (there are kinks in the hydrocarbon chains).
Why is an unsaturated fat often more fluid?
Because of the kinks stopping neighbouring triglycerides from lying too close together.
Why do unsaturated fats have lower melting points?
It is less compact so less energy is required to separate the molecules.
What are unsaturated fats also referred to?
As oils.
What does mono-unsaturated mean?
When there is one double bond in a fatty acid.
What does poly-unsaturated mean?
Where there are multiple bonds in a fatty acid.
Compare animal fats to plant fats.
Animal fats are saturated, occur as fats and are healthier. Plant lipids are unsaturated and occur as oils.
Give other examples of lipids other than triglycerides.
Waxes, steroids, terpenes and phospholipids.
What is the difference between a fatty acid and phospholipid?
The fatty acid group is replaced by a phosphate group.
How do phospholipids behave in water?
Their heads (phosphate group) is hydrophlic but the tail (hydrocarbon) is hydrophobic.
