1. What do you use fats for? All around your body?
lipids
What do you use fats for?
All around your body?

2. Basic Structure
All lipids contain three elements Carbon, Oxygen and Hydrogen
They are known as neutral fats as they have mostly uncharged and are hydrophobic so do not readily dissolve in water
Essentially it is a massive ester (remember these from GCSE chemistry?)
Who can remember the ester bond?

3. Structure and formation

4. Fatty acid Really long carboxylic acid general structure Cn H2n+1 COOH
Draw one with 5 carbons
Do one saturated one unsaturated

5. More gubbins
Ones without double bonds are called – saturated – solid at room temperature due to H-bonds
Ones with some double bonds are called – unsaturated – liquid at room temperature – less H-bonding
Really useful as energy storage as they are reduced (lots of hydrogen) and anhydrous they store a lot of energy in them there bonds
And once you chop off all the hydrogens what do you make – water! This is why camels store fat
They bond with Glycerol in a process called esterification

6. Structural formula Look at the shape
The kinks in the unsaturated explains why unsaturated fats are liquids
The un straight chain prevents the chains lining up to do H-bonds

7. Formation All you need is one Glycerol and some fatty acids
The process is called ESTERIFICATION and is a Condensation Reaction
The reverse is a Hydrolysis reaction
The product with a Glycerol molecule is a Tri, Bi or mono glyceride (dependent of how many fatty acids we have)
Glycerol is C3H8O3

8. Uses of Fats On white boards how many uses of Fats can you think of
Did you get:
Energy Source – remember they are stored in adipose tissue and are insoluble so do not affect osmotic pressure
Membranes
Waxes and Oils for waterproofing in plants and animals
Protection from cold (insulating) and shock (impact)
Source of metabolic water

9. So that is big lipids Now for ickle lipids can you think of any?
I give you
Phospholipids
Cholesterol
What can you tell me about them?

10. Phospholipids Special di-glyceride molecules (two chains)
They are made from one phosphate group, glycerol and two fatty acid chains
The phosphate end is the hydrophilic end and the other is hydrophobic
The Hydrophobic ends attract to form a bi layer
They are amphipathic which means they are hydrophilic and hydrophobic

11. Structural formula

12. Cholesterol The most misunderstood of all fats Is it bad?
Or is it vital to your survival?
Decide and explain

13. Structure
A type of sterol lipid – has the same structure as most steroids
3 hexose carbon rings
One pentose carbon ring
Carbon chain
Hydroxyl group – Hydrophilic
Helps provide structure to the membrane

14. Higher or Lower The thing with cholesterol is they are seen as bad
When I was your age they told us to not eat eggs – full of cholesterol
There are different types molecules called lipoproteins in your body – and your body makes both their job is to move cholesterol on
High density is good
Low density is bad – this causes blockages

15. Questions
What are the main components of a triglyceride and what bonds hold them together?
Why do lipids have a hi energy content?
Describe esterification
What are the products of hydrolysis of a triglyceride?
What are the biological roles of lipids
Suggest hoe the structure of the membrane of an arctic fish may differ from a tropical fish
How does cholesterols structure allow it to perform it’s role in cell membranes?