lipids Flashcards
What are the chemical elements lipids contain?
Carbon, hydrogen and oxygen.
What are lipids like in organic solvents and water?
Organic solvents - soluble
Water - insoluble
What are simple lipids called?
Triglycerides.
What are they made of?
One glycerol and 3 fatty acid molecules.
Which groups from fatty acids and glycerol line up next to each other to form triglycerides?
The “OH” groups.
What three reactions take place and what molecules are lost and what is the bond formed?
- 3 condensation reactions take place.
-3 water molecules are lost. - 3 ester bonds are formed.
What is meant by saturated?
- No double bonds between carbon atoms.
What is meant by mono-saturated?
- One double bond between carbon atoms.
What are the other types of lipids besides triglycerides?
Phospholipids and sterols.
What makes phospholipids different to triglycerides?
- One of the 3 fatty acids is replaced by a phosphate group
What do phospholipids make up?
Cell membrane structure.
What happens when phospholipids are exposed to water?
- The hydrophilic phosphate heads are attracted to the water, and the hydrophobic tails are repelled.
- For this reason they are called “surface active agents”.
What is an example of a sterol?
Cholesterol.
What allows cholesterol to fit in between the phospholipids?
The flattened shape, with the hydrophilic regions being towards the outside of the membrane.
What role does cholesterol in membranes?
Helps make membranes less fluid and more rigid.
