Bell ringer Peer mark Carbs WS

Lesson objectives describe the molecular structure of a triglyceride with reference to the formation of ester bonds and relate the structure of triglycerides to their functions in living organisms describe the structure of a phospholipid and relate the structure of phospholipids to their functions in living organisms

Lipids: Fats & Oils

Reasons our bodies need fat Provides a concentrated source of energy Surrounds and protects certain vital organs Forms an insulating layer beneath the skin to keep in body heat Forms part of the structure of cell membranes Provides a source of fat soluble vitamins Provides a reserve of energy for long term storage Provides texture and flavour in foods Foods containing fat provide a feeling of fullness as digestion is slow

Lipids fat Lipids are composed of C, H, O Diverse group long hydrocarbon chain Diverse group fats phospholipids steroids Do not form polymers big molecules made of smaller subunits not a continuing chain fat Made of same elements as carbohydrates but very different structure/ proportions & therefore very different biological properties

Characteristics of Lipids Composed of Carbon, Hydrogen, and Oxygen Greater than 2:1 ratio of H:O Includes fats, oils, phospholipids, and cholesterol Building blocks are fatty acids and glycerol. Energy storage molecules Phospholipids part of cell membrane 6

Types of Lipids Lipids with fatty acids Waxes Fats and oils (trigycerides) Phospholipids Sphingolipids Lipids without fatty acids (similar properties, not structure) Steroids

Dehydration synthesis Condensation reaction enzyme Pulling the water out to free up the bond enzyme enzyme

Task Use the cut and stick activity to make a triglyceride, glue it in your book Use the model and the textbook to complete the worksheets on carbohydrates

Saturated and Unsaturated Fatty Acids Saturated : C–C bonds Unsaturated : one or more C=C bonds

Fatty Acid Structure Carboxyl group (COOH) forms the acid. “R” group is a hydrocarbon chain. 12

Unsaturated Fatty Acid Saturated Fatty Acid 13

Glycerol 14

Synthesis of a Lipid 15

Check your work

Triglyceride Formation - Modelling Cut out the parts of the molecules and stick them in your books to show how a triglyceride is formed Label glycerol Label triglyceride Label sterification and hydrolysis

Plenary

Self-assessment

Self-assessment