Lipids Flashcards
What does a triglyceride contain?
A glycerol molecule and three fatty acids.
What does a phospholipid contain?
A glycerol molecule, with two fatty acids and a phosphate group.
How are triglycerides formed?
By three condensation reactions between glycerol and three fatty acids.
What is also produced when a triglyceride is formed?
Three molecules of water from each condensation reaction.
What is the worded equation for the formation of a triglyceride?
Glycerol + 3 fatty acids = triglyceride + 3 water molecules.
What is the bond formed between the glycerol and each fatty acid in a triglyceride?
Ester bond.
What are saturated fatty acids?
A fatty acid where the hydrocarbon chain has only single bonds between carbons.
What are unsaturated fatty acids?
Fatty acids where the hydrocarbon chain consists of at least one double bond between carbons.
What are the properties of triglycerides?
Energy storage, metabolic water source, insoluble, and have a low mass.
How is energy stored in a triglyceride?
Due to the large ratio of energy storing carbon-hydrogen bonds.
What can triglycerides release if they are oxidised?
Water.
How can triglycerides release water when oxidised?
Due to the high ratio of hydrogen to oxygen atoms.
Why are triglycerides insoluble?
As they are large, hydrophobic molecules that don’t affect water potential and osmosis.
What makes triglycerides a good storage molecule?
They are insoluble.
What is the benefit of lipids having a low mass?
A lot can be stored without increasing the mass and preventing movement.
What is the emulsion test for lipids?
The sample is dissolved in ethanol and shaken, distilled water is then added and it’s shaken again.
What is a positive result for the emulsion test for lipids?
A white emulsion appears.
How are phospholipids formed?
By two condensation reactions between glycerol and two fatty acids.
What is the bond formed between the glycerol and each fatty acid in a phospholipid?
Ester bond.
Why are phospholipids polar?
They have two charged regions.
What are the two regions of a phospholipid?
The hydrophilic head and hydrophobic tail.
What is the hydrophilic head of a phospholipid attracted to and why?
Water, as it is polar.
What does the hydrophilic head on a phospholipid repel?
Fats.
What is the hydrophobic tail repelled by and why?
Water, as it is non-polar.
What does the hydrophobic tail mix with?
Fats.
What do lots of phospholipids form?
A bilayer membrane structure.
What are the heads and tails of a phospholipid exposed to?
The heads are exposed to water and the tails face each other.
