Lesson starter What is the difference between alpha and beta glucose? What type of reaction involves glucose molecules joining up together to make glycogen?

What do all these foods have in common? Title: Lipds 16 November 2018 Learning question: Why are lipids important in the human body? Homework: Homework due Wednesday 21st October LP6 and 7 What do all these foods have in common?

Key words Saturated Unsaturated Condensation reaction Ester bond Triglyceride Glycerol Fatty acids

Aims from specification describe, with the aid of diagrams, the basic structure of glycerol and fatty acids; outline the formation of triglycerides by the condensation reactions between glycerol and fatty acids; describe the structures of saturated and unsaturated fatty acids and outline their roles and importance in the human body; describe, with the aid of diagrams, the structure of a phospholipid molecule.

About lipids – some facts you need to know Lipids cover a large group of molecules that include fats, oils and cholesterol Lipids are non-polar molecules. Lipids are hydrophobic, which makes them insoluble in water. What do the sentences above mean? Write them out in every day language to help you remember them.

Fats and oils Types of lipids known as triglycerides. Made up of one glycerol molecule joined to three fatty acids.

describe, with the aid of diagrams, the basic structure of glycerol and fatty acids

A fatty acid molecule is a hydrocarbon with a carboxylic acid group attached

Fats and oils – condensation reactions Three fatty acids join on to one glycerol molecule by a condensation reaction. The bonds formed are called ester bonds. The molecule formed is a triglyceride

outline the formation of triglycerides by the condensation reactions between glycerol and fatty acids;

Task 1 – Fatty acids Read the section “Fatty acids” on page 24 Make a table to summarise the differences between saturated and unsaturated fatty acids Write down 4 key words on your whiteboard to share with the class

Task 2 – uses of lipids in the body Type of lipid Use

Fatty acids Saturated fatty acids Unsaturated fatty acids Hydrocarbon chains have the maximum number of hydrogen atoms attached – it is saturated We know this because all the bonds are single bonds Saturated fatty acids tend to have higher melting points so are solid at room temperature Has double bonds between carbons – does not have as many hydrogen atoms, therefore is unsaturated Tends to be liquid at room temperature e.g. oils

describe the structures of saturated and unsaturated fatty acids and outline their roles and importance in the human body;

Cholesterol Is a kind of steroid but does not have the same structure Found in the plasma membrane to keep it fluid Other steroids are important as hormones Testosterone Oestrogen

Phospholipids These are polar molecules that form a bilayer in cell membranes Contain glycerol and two fatty acids and a phosphate group attached to the head region

Transport of lipids Lipids are not soluble in water This means that they cannot be dissolved in blood plasma and carried around the body in the same manner as glucose Triglycerides are broken down to glycerol and fatty acids. Glycerol dissolves into the blood plasma Fatty acids combine with plasma proteins and carried in the blood as small globules

Plenary - Exam questions

Plenary - Exam questions

Exam answers