Lipids

-Carbon, Hydrogen and Oxygen

• No - Are macromolecules-> small repeating units

• Phospholipid • Cholesterol • Triglycerides

• 1 glycerol + 3 fatty acids - 3 ester bonds

• Formed by condensation reaction between -OH groups of carboxylic acid + -OH group of alcohol • Has ester bonds-> triglyceride has 3 ester bonds • Process is ESTERFICATION

• Have double carbon bond (C=C) • Found as oil->healthier • Lower melting point- liquid -> bent tails means less fatty acid in a place

• Contains only single bond (C-C)- • High melting point= solid ->straight tails so more fatty acids in a place • Found as solids-> unhealthy

• Less dense than water= buoyancy of aquatic animals • Insoluble (hydrocarbon chain)= no effect on water potential of cells +used for waterproofing-> aquatic animals • Slow conductor of heat= thermal insulation • High energy: mass ratio= better energy storage

• Has 1 phosphate group, 1 glycerol + 2 fatty acids • Phosphate= hydrophilic • Fatty acid=hydrophobic

• Forms a phospholipid bilayer= component of membranes - Centre of bilayer is hydrophobic- water soluble substances cannot pass through easily

• Steroid structure of 4 hydrocarbon rings • Has hydrocarbon rings attached with hydrocarbon tail • > ring structure has OH group attached HO- Hydrocarbon ring- Hydrocarbon tail

• Helps strengthen cell membrane by interacting with phospholipid bilayer • Adds stability to phospholipid bilayer • Reduced fluidity