Lesson 3 - Lipids Flashcards
what is the difference between oils and fats
fats are solid at room temperature whilst oils are liquid
what elements are lipids made out of
carbon, hydrogen & oxygen
what are the 2 types of organic chemicals that make up lipids
fatty acids and glycerol, combined using ester bonds
all fatty acids have a long hydrocarbon chain. What does this mean?
a pleated backbone of carbon atoms with hydrogen atoms attached, and a carboxyl group at one end
how many different kinds of fatty acids are there
70
how do fatty acids vary in 2 ways
- a different length of carbon chain
- fatty acids may be saturated or unsaturated fatty acids
what is the difference between saturated and unsaturated fatty acids
saturated fatty acids only consists of single covalent bonds between the carbon atoms, whilst unsaturated fatty acids have double covalent bonds
what is a monousaturated fatty acid
a fatty acid with 1 double covalent bond
what is a polyunsaturated fatty acid
a fatty acid with 2+ double covalent bonds
what is an ester bond
a bond formed in a condensation reaction between the carboxyl group of a fatty acid and one of the hydroxyl groups of glycerol
what is esterification
the formation of ester bonds
do fats have unsaturated or saturated fatty acids
saturated
do oil have unsaturated or saturated fatty acids
unsaturated
what happens when lipids are oxidised during respiration
the bonds are broken and carbon dioxide and water are produced. This reaction drives the production of a lot of ATP
what are 4 characteristics/ functions of lipids
- waterproofing
- good insulators
- buoyancy
- insoluble in water
how are lipids good insulators
a fatty sheath insulates your nerves so the electrical impulses travel faster, and form blubber
how are lipids buoyant
because they have a low density
how are lipids insoluble in water
so lipids do not intervene with water-based reactions in the cytoplasm
how is a phospholipid formed
when a hydroxyl group of a glycerol undergoes an esterification reaction with a phosphate group
describe the phosphate head
is polar as it carries a small negative charge, so is hydrophillic and dissolves in water
describe the phosphate tail
is neutral, so is hydrophobic and does not dissolve in water
describe a monolayer
a single closely packed layer of phospholipids -> structure of the membranes
describe a micelle
a spherical formation of molecules in water with the hydrophobic areas in the middle and hydrophilic areas outside
what is a bilayer
a double layer of closely packed atoms and molecules
