Lipids Flashcards
How are lipids different from proteins and carbohydrates?
They are not polymers formed from long chains of monomers.
What do all lipids contain?
Hydrocarbons.
What are hydrocarbons?
Molecules that contain only hydrogen and carbon atoms.
What are the two types of lipids?
Triglycerides.
Phospholipids.
What are triglycerides made up of?
One molecule of glycerol with three fatty acids attached to it.
What are the fatty acids in triglycerides made of?
The fatty acids have long tails made of hydrocarbons.
Why are triglycerides insoluble in water?
The tails are hydrophobic.
Define hydrophobic.
Repels water molecules.
What is the structure of fatty acids?
They all contain the same basic structure (COOH), but the hydrocarbon tail varies.
What are the two kinds of fatty acids?
Saturated fatty acids.
Unsaturated fatty acids.
What is a saturated fatty acid?
Doesn’t have any double bonds between the carbon atoms. It is saturated with hydrogen.
What is an unsaturated fatty acid?
Has double bonds between the carbon atoms, which causes the chain to kink.
How are triglycerides formed?
Condensation reactions.
What bond forms between the glycerol and a fatty acid when a triglyceride is formed?
Ester bond.
Where are phospholipids found?
Cell membranes.
What are phospholipids made up of?
A glycerol molecule with a phosphate group and two fatty acids attached to it.
What is the phosphate group in phospholipids?
Hydrophilic.
Define hydrophilic.
Attracts water molecules.
What are the fatty acids in phospholipids?
Hydrophobic.
What are triglycerides mainly used as?
Storage molecules.
Why are triglycerides good storage molecules?
The long hydrocarbon tails of the fatty acids contain lots of chemical energy - a load of energy is released when they’re broken down.
What do triglycerides bundle together as?
Insoluble droplets in cells because the fatty acid tails are hydrophobic - the tails face inwards, shielding themselves from water with their glycerol heads.
What do phospholipids make up?
The bilayer of cell membranes.
What do cell membranes do?
Control what enters and leaves a cell.
