3.1.3 Lipids Flashcards
What are they the only molecules not to be made up of
polymers
What are the 3 groups of lipids
Fats
Phospholipids
Steroids
4 properties all lipids share
Made from carbon, oxygen and hydrogen
Have less oxygen than carbohydrates
Insoluble in water (hydrophobic)
Soluble in alcohol and acetone (organic solvents)
5 things lipids do
Cell membranes Protection Insulation Energy Waterproofing
What lipids are in cell membranes
What do they do there
Phospholipids
Provide flexibility and control substance movements
What lipids provide protection and where
Fat around delicate organs
What lipids are used for insulation in the body
Why
Fats
They’re slow heat conductors so a thin layer preserves heat
Insulates neurones (myelin sheath) - adipose tissue
What lipids are used for energy when they’re oxidised, what do they do
Fats
Release x2 energy of carbohydrates whilst releasing water
What do plants and animals rely on to make them waterproof
Waxy cuticles
What lipids do mammals release
Oily secretion
What’s the correct name for fats
Triglycerides
What’s the structure of 1 triglyceride
3 fatty acid chains bonded to a glycerol backbone
What are triglycerides in
Butter, oils, foods
What’s glycerol
An alcohol formed from 3 carbons
What does each carbon atom have attached to it in a triglyceride
A hydroxyl group
What’s glycerol bound to in a triglyceride
3 fatty acids
What are fatty acids formed from
Long hydrocarbon chains (usually 16-18 carbons)
What do fatty acids end in
A carboxyl group (COOH)
What are carboxyl groups
Oxygen double bonded to carbon double bonded to hydroxyl group (-COOH)
How many different fatty acids are there
Over 70
What will each different triglyceride have different and the same
Same glycerol
Different fatty acid attached to glycerol
What type of molecules are triglycerides
Non-polar
What do polar molecules have
2 ends (poles) that behave differently from one another e.g 1 side +, 1 side -