Lipids

3.1.3

What are Lipids made from?

Carbon, hydrogen and oxygen

What are triglycerides made from?

1 glycerol and 3 fatty acids

How are triglycerides formed?

By an ester bond in a condensation reaction

Saturated lipid

Don’t contain carbon-carbon double bond

Unsaturated lipid

Contain carbon-carbon double bond

How does a double bond affect unsaturated lipids?

Not able to bend and can’t pack together as tightly

How does a double bond affect the structure of unsaturated lipids?

Liquid at room temperature

Why are Triglycerides a great energy store?

Have a high ratio of energy storing C-H bonds to carbon atoms

What does a low mass to energy ratio in a triglyceride mean?

It’s a good storage molecule as lots of energy can be stored in a small volume

Why are triglycerides insoluble in water?

They are large and non-polar so they don’t affect water potential

What does triglycerides do as a result of having hydrogen-oxygen atoms?

releases water when they’re oxidised

What do phospholipids contain?

1 phosphate head and 2 fatty acids

Property of phosphate head?

Hydrophilic

Property of fatty acid tails

Hydrophobic

What forms when phospholipids are in contact with water?

Micelles

What happens as a result of phospholipids being polar?

A bilayer can be formed

Why does the structure allow to form glycolipids with carbohydrates?

for cell recognition

Emulsion test

Crush sample with water and add ethanol

Positive result of emulsion test?

Cloudy