Lipids Flashcards
are lipids polar or non-polar?
non polar.
are lipids soluble in water?
no as they are non polar.
what is a macromolecule?
a large complex molecule that is not built from monomers.
how is a triglyceride made?
combining one glycerol molecule with three fatty acids.
what group of molecules is glycerol from?
alcohols
what group of molecules are fatty acids from?
carboxylic acids.
what is the reaction between glycerol and fatty acids called?
esterification (an example of a condensation reaction) three water molecules are removed.
what are the bonds formed between glycerol and fatty acids called?
ester bonds.
what is a saturated fatty acid?
a fatty acid chain wih no double bonds between carbon atoms.
what is an unsaturated fatty acid?
a fatty acid chain with double bonds between some carbon atoms.
what are the different types of unsaturated fatty acids?
monounsaturated - one double bond.
polyunsaturated - two or more double bonds.
why are unsaturated fatty acids oils?
the presence of double bonds between carbon atoms makes the molecule kink. this means they cannot pack as closely together so they are liquid at room temperature rather than solid.
what is a phospholipid?
modified triglycerides that contain phosphurus.
why are phospholipid heads soluble in water?
phosphate ions are negatively charged so theyre soluble in water.
how many fatty acid tails are in a phospholipid?
2
what are sterols?
another type of lipid found in cells. complex alcohol molecules
what are the roles of lipids?
- membrane formation
- hormone production
- electrical insulation for nerve transmission.
- thermal insulation to reduce heat loss.
- cushioning to protect vitaly organs.
- buoyancy for aquatic life.
what is the chemical test for lipids?
the lipid emulsion test.
how do you conduct the lipid emulsion test?
- sample is mixed with ethanol.
- solution is mixed with water and shaken.
- if lipids are present a cloudy white emulsion will form on the top of the solution.
what is food synergy?
the idea that nutrients do not work in isolation, but together.
why is the data is food reports often flawed?
- people tend to underestimate how much they eat.
- different genetics respond to nutrients differently.
