Lipids Flashcards
What are the 4 main types of lipids?
Triglyceride
Phospholipid
Steroid
Wax (in plants)
What is the structure of a Triglyceride?
Glycerol backbone attached to 3 fatty acid chains
How are triglycerides formed?
Through esterification (a condensation reaction):
Glycerol has an -OH attached to each of its (3) carbons
Each fatty acid forms an ester bond with the hydroxyl group and a water molecule is released per ester bond formed (RCOOH)
What is the difference between a saturated and unsaturated fat and what is the significance?
Saturated fats do not have double bonds (saturated with hydrogens)
Unsaturated fats have double bonds
The double bonds in unsaturated fats creates a bent structure. This means that the fatty acids are pushed further away from each other, resulting in less Van der Waal forces between them.
-> They have a lower melting temperature
What is the structure of a phospholipid?
Hydrophillic head:
- phosphate group attached to a glycerol backbone
R group:
- attached to the phosphate group
- the type of phospholipid will depend on this group
Hydrophobic tail:
- consists of 2 fatty acid chains
What is the characteristic structure of a steroid?
They are usually characterised by their 4 ring hydrocarbon structure
Some examples of steroids
- Cholesterol
Steroid hormones:
- cortisol
- aldosterone
- all sex hormones- testosterone, estrogen, progesterone
What is the importance of cholesterol?
Important for cell membrane structure and function
- Regulates fluidity of cell membrane (structure)
- influences activity of certain proteins in the membrane
Important for synthesis of steroid hormones (precurser)
Bile production
Insulates myelin sheath
Where are lipids produced?
Smooth ER
