Lipids Flashcards
What are triglycerides made from and what are they bonded by?
- 3 fatty acids
- glycerol molecule
- joined together by ester bonds (this is known as esterification a condensation reaction)
How do break the bonds in triglycerides?
By a hydrolysis reaction, which adds 3 water molecules to reverse the reaction.
Saturated
Has no double bonds between carbon atoms, as they are saturated by hydrogen atoms.
Unsaturated
They have some double bonds between carbon atoms. The double bonds cause the molecule to bend and cannot be packed closely. This makes them a liquid at room temperature. They are described as oils rather than fats.
Mono-unsaturated
There is just 1 double bond between carbons.
Polyunsaturated
There are 2 or more double bonds between carbons.
Which is healthier saturated or unsaturated?
Unsaturated tend to be healthier. This is because there is some evidence to suggest that saturated fats lead to Conakry heart disease.
What are Phospholipids made from?
- 2 fatty acids
- glycerol
- a phosphate group
Phosphate characteristics
Phosphate ions have extra electrons so they are negatively charged. This makes them soluble in water and hydrophilic.
Fatty acid characteristics
Fatty acids are hydrophobic
What is a Phospholipid monolayer and what is it use
By having there heads in the water and their tails in the air. They are surface active agents or surfactants.
What does the Phospholipid bilayer form and what is its function
Form the cell surface membrane to separate aqueous environments from the cytosol within the cell.
What is the structure of a Sterols
Are complex alcohol with 4 carbon ring structures with hydroxyl (OH) group at the end. The hydroxyl group is hydrophilic and the rest of the molecule is hydrophobic.
What is cholesterol and where is it made?
Cholesterol is a sterol and is made in the liver and intestines.
Function of cholesterol
Adds stability and regulates fluidity by keeping it at low temperatures.
Cholesterol is also used when manufacturing vitamin D and steroid hormones.
Because it is small and flat it can fit in between phospholipid.
