Lipids Flashcards
What are lipids commonly known as?
Fats and oils
What are lipids made from?
A variety of components but they ALL contain hydrocarbons
What are the two types of lipids?
Triglycerides
Phospholipids
What makes up a trigylceride?
Three fatty acids
One glycerol molecule
Are the fatty acid tails in triglycerides hydrophobic or hydrophillic?
Hydrophobic
Are lipids soluble or insoluble in water? Why?
Insoluble
Hydrocarbon tails are hydrophobic
What makes up a fatty acid?
A carbon atom
Variable ‘R’ group hydrocarbon tail
What are the two types of fatty acids?
Saturated
Unsaturated
Whats the difference between saturated and unsaturated?
Saturated=Single bonds
Unsaturated=doUble bonds
What do the double bonds in unsaturated fats cause the chain to do?
kink
Through what reaction are triglycerides formed?
Condensation
What type of bond forms between the fatty acid and glycerol molecule?
Ester bond
How many times does the reaction take place to form a triglyceride?
3
Where are phospholipids found?
Cell membranes
What components make up a phosphoplipids?
one glycerol molecule
one phosphate group
two fatty acids
Is the phosphate group hydrophobic or hydrophillic?
hydrophillic
What are triglycerides used as? Why are they good for this job?
energy storage molecules
the long hydrocarbon tails contain lots of chemical energy
How does a triglyceride being insoluble benefit them for storage?
They dont affect water potential of cells so they dont cause the cell to swell up
What do phospholipids make up?
the bilayer of cell membranes
Do phospholipid heads face away or towards the water?
Towards the water
What do phospholipids heads do?
make it difficult for water soluble substances to pass through the cell membrane
Describe the test for lipids.
EMULSION TEST 1) add ethanol to the substance 2) shake 3) add to water positive test = milky colour
