LIPIDS (FATS) Triglycerides and phospholipids are two groups of lipid. Triglycerides are formed by the condensation of one molecule of glycerol and three.

LIPIDS (FATS)

Triglycerides and phospholipids are two groups of lipid.Triglycerides are formed by the condensation of one molecule of glycerol and three molecules of fatty acid.A condensation reaction between glycerol and a fatty acid (RCOOH) forms an ester bond.The R-group of a fatty acid may be saturated or unsaturated.In phospholipids, one of the fatty acids of a triglyceride is substituted by a phosphate-containing group.The different properties of triglycerides and phospholipids related to their different structures.The emulsion test for lipids.

Students should be able to:•• recognise, from diagrams, saturated and unsaturated fatty acids•• explain the different properties of triglycerides and phospholipids.

Identify the two types of Lipids What are the components of each

type of lipid? What are the properties of the lipids? What are the functions/roles of lipids?

Outcomes: - name the two types of lipids.

- Outline using diagrams how triglycerides are formed from its parts

- describe and explain the difference between saturated and unsaturated lipids.

- discuss the roles of triglycerides

https://www.youtube.com/watch?v=eB793h16R8A

Triglycerides

1 molecule of glycerol 3 molecules of fatty acids joined

by condensation reactions

Outcomes: - name the two types of lipids.

- Outline using diagrams how triglycerides are formed from its parts

- describe and explain the difference between saturated and unsaturated lipids.

- discuss the roles of triglycerides

Roles of Triglycerides:

Energy source (lipids contain twice the energy content as carbohydrates)

Waterproofing (lipids are insoluble, some plants have a waxy cuticle to keep out the water from leaves) A good term to use is hydrophobic

Insulation (fats are slow conductors of heat and good insulators to retain heat)

Protection (fats are often stored around internal organs to protect them)

Outcomes: - name the two types of lipids.

- Outline using diagrams how triglycerides are formed from its parts

- describe and explain the difference between saturated and unsaturated lipids.

- discuss the roles of triglycerides

Saturated fats vs Unsaturated fatsThe fatty acid chains don’t always have to be the same length. Different fats have different

length of the fatty acid. Also sometimes they chains have

double bonds in

Outcomes: - name the two types of lipids.

- Outline using diagrams how triglycerides are formed from its parts

- describe and explain the difference between saturated and unsaturated lipids.

- discuss the roles of triglycerides

Plenary: Whiteboards

1. What are the 2 types of lipids?2. Name the components of a triglyceride3. Draw a simple triglyceride4. What reaction joins the components

together?5. Why would we say that lipids are not

polymers6. 2 roles of lipids/fats?7. What do the terms: Saturated,

unsaturated and polyunsaturated mean?

8. What state are polysaturated fats? Why is this?

9. What state are saturated fats likely to be?

Outcomes: - name the two types of lipids.

- Outline using diagrams how triglycerides are formed from its parts

- describe and explain the differences between saturated and unsaturated lipids.

- discuss the roles of triglycerides

Lets get started: Quick recall test

Answer the questions in the back of your notes.

Outcomes: - name the two types of lipids.

- Outline using diagrams how phopholipids are formed from its monomers

-explain the properties of phospholipids and link to their function

- use the emulsion test to identify the presence of lipids in solutions.

Phospholipids

1 molecule of glycerol 2 fatty acids joined by condensation reactions 1 phosphate group joined instead of a fatty

acid by condensation reactions.

Outcomes: - name the two types of lipids.

- Outline using diagrams how phopholipids are formed from its monomers

-explain the properties of phospholipids and link to their function

- use the emulsion test to identify the presence of lipids in solutions.

Phospholipids - properties

The phosphate group is hydrophilic (polar) The fatty acids are hydrophobic (non polar).

http://www.johnkyrk.com/cellmembrane.html

Outcomes: - name the two types of lipids.

- Outline using diagrams how phopholipids are formed from its monomers

-explain the properties of phospholipids and link to their function

- use the emulsion test to identify the presence of lipids in solutions.

Test for Lipids (Lab books)

Title: Testing for Lipids Aim: to identify which food

substances contain high lipid content.

Method: Write yourself Risks: Write yourself Results table: similar to the

tests for sugars (adapt from this)

Conclusions: Sum up which foods contain high fat content and how you could tell.

Outcomes: - name the two types of lipids.

- Outline using diagrams how phopholipids are formed from its monomers

-explain the properties of phospholipids and link to their function

- use the emulsion test to identify the presence of lipids in solutions.

Plenary – Summary Questions

Fats and oils make up a group of lipids called __ which when hydrolysed form their components____ and fatty acids. A fatty acid with more than one C=C (double bond) is called ___. In a phospholipid, the number of fatty acids attached is __. These are described as ___ because they repel water. Phospholipids are used in creating the ___ because they are ____.

Outcomes: - name the two types of lipids.

- Outline using diagrams how phopholipids are formed from its monomers

-explain the properties of phospholipids and link to their function

- use the emulsion test to identify the presence of lipids in solutions.