Lipids Flashcards
What elements do lipids contain?
Carbon, hydrogen and a little bit of oxygen
What are lipids made up of?
Glycerol and 3 fatty acids
What happens when lipids are put in water?
Nothing they are insoluble
They contain a lot of carbon and hydrogen what property does that give them?
Non polar and hydrophobic
What happens when you put lipids in alcohol ans other lipids?
They react as they are soluble in other solvents
What are the two types of lipids?
Triglycerides and phospholipids
How do you know if it is a saturated fatty acid?
Only have single C-C bonds so they form linear hydrocarbon chains
What are 4 properties of saturated fatty acids?
Strong attractions between fatty acid chains, high melting points, solid at room temperature and fit closely together in a regular pattern
How can you tell if a fatty acid is unsaturated ?
One or more carbon double bonds C=C so the hydrocarbon chain bends due to there being fewer hydrogens they have less energy
When a unsaturated fatty acid has one C=C bond what is it called?
Mono unsaturated fatty acid
When a unsaturated fatty acid has more than one C=C bond what is it called?
Poly unsaturated fatty acid
What are 4 properties of unsaturated fatty acids?
Fewer interactions with fatty acid chains so weaker attractions, low melting points, liquid at room temperature and they push each other apart forming irregular patterns
How do you test for lipids?
Emulsion test add ethanol then water.
What is the colour change if lipids are present?
Colourless to a milky white emulsion
Why do lipids form a milky white emulsion?
Lipids are soluble in ethanol but insoluble in water so ethanol dissolves the lipids s
What are triglycerides made up of?
Glycerol head and 3 fatty acid tails
What type of molecules are triglycerides?
Non polar hydrophobic moelcules
What do the 3 fatty acids determine?
Properties
How many hydrocarbons are triglycerides generally made up of?
15-17 carbons
What are the glycerol and fatty acids joined together by?
Ester bonds
How are triglycerides an important source of water?
High ratio of hydrogen to oxygen atoms so release water when oxidised
What do triglycerides hydrophobic properties make them useful for?
Waterproofing agent on feathers leaves and exoskeletons of insects
Why are triglycerides an excellent source of energy?
They have a high ratio of energy storing carbon hydrogen bonds to carbon atoms
Why are triglycerides a good storage molecule?
Have a low mass to energy ratio so they can store lots of energy in a small amount of space
What does their low density mean they are useful for?
Buoyancy, insulation and protection
What are phospholipids made up of?
Phosphate polar hydrophilic head and a non polar hydrophobic tail
What are phospholipids a component in?
Cell membranes
What happens when phospholipids are put in water?
Heads close to water tails in the middle
What structure do steroids like cholesterol have?
Four ring structure
What are waxes
Similar to fats and oils but are found on leaves and insects
