Lipids Flashcards
what do all lipids contain?
carbon, hydrogen and oxygen
what are all lipids soluble in?
they are insoluble in water, but soluble in organic solvents such as alcohols or acetone.
what are the five roles of lipids?
- cell membrane
- source of energy (when oxidised)
- waterproofing
- Insulation
- protection
what are triglycerides?
three fatty acids combined with glycerol
what bonds do the fatty acids have with the glycerol in a triglyceride
an ester bond
what reaction do the fatty acids and glycerol undergo to create a triglyceride
a condensation reaction
why are the properties of fats and oils different?
the variations of fatty acids (there are over 70 different fatty acids)
what does saturated mean?
there are no double bonds between carbon atoms in a triglyceride.
what does mono-unsaturated mean?
there is only one double bond between carbon atoms in a triglyceride.
what does polyunsaturated mean?
there are more than one double bonds between carbon atoms in a triglyceride.
why are triglycerides a good source of energy?
there are more energy-storing carbon-hydrogen bonds than carbon atoms
Why are triglycerides good for storage?
they have a low mass to energy ratio. They are very compact so they can be put in small spaces but they hold a lot of energy.
what are phospholipids?
they are similar to the structure of a triglyceride however one fatty acid is replaced by a phosphate molecule.
why are phospholipids attracted and also repelled by water?
the two fatty acid molecules repel water however the phosphate molecule attracts water.
what is mean by Hydrophobic tail
the tail moves itself away from the water but mixes readily with fat
