CHEM215 Lecture Notes - Lecture 4: Cell Membrane, Mouthfeel, Phosphatidylcholine
Wk 2:2 - Lipids
Lecture outcomes:
• the importance of lipids - where are they found and what do they do?
• Properties of lipids
• Introduction to the different classes of lipids and their structures - ie. understanding
the ingredient labels on our food
• Focusing on the structure of triacylglycerides and the nomenclature of TAGS
• Learning how to name them
Lipids:
• a source of fuel
• Efficient storage of fuel
• Cell structural components
• Provide insulation and protection
• Metabolic precursors
• Gene regulators
• Satiety enhancers
• Flavour and mouth feel.
In mammals, 5-25% of body weight is fat. Most of the fat constitutes primary energy
reserves - fat stores 6x as much energy as glycogen.
Plant seeds store great quantise of fat to provide energy for the developing plant embryo.
Three classes of lipids:
1. Triacylglycerides (TAGS)
2. Phosphatidyl choline
find more resources at oneclass.com
find more resources at oneclass.com
Wk 2:2 - Lipids
3. Cholesterol
Properties and definitions of lipids:
• made from C,H,O - no nitrogen present
• immiscible with water
• Components of food
• Energy dense
• Fats are solid at room temperature; oils are liquid at room temperature.
• Triglycerides are main form of lipids in food and body
• Triglycerides - 95% of dietary fats; can be short, medium or long-chained and can
be saturated, monounsaturated or polyunsaturated.
• Cholesterol is found in animals membranes
• Phospholipids form a bimolecular sheet as FAs are too bulky to fit in the
micelle interior.
• Fats dissolve fat-soluble vitamins; serve as source of essential fatty acids; insulate
and protect organs.
• Recommended daily intake: 30% of kJs from total fat; 10% from sat fats and
300mg of cholesterol.
Properties of lipids:
• Fatty acids are the simplest lipids, and they are also constituents of more complex
liquids.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture outcomes: the importance of lipids - where are they found and what do they do: properties of lipids. Introduction to the different classes of lipids and their structures - ie. understanding the ingredient labels on our food: focusing on the structure of triacylglycerides and the nomenclature of tags, learning how to name them. Lipids: a source of fuel: efficient storage of fuel, cell structural components, provide insulation and protection, metabolic precursors, gene regulators, satiety enhancers, flavour and mouth feel. In mammals, 5-25% of body weight is fat. Most of the fat constitutes primary energy reserves - fat stores 6x as much energy as glycogen. Plant seeds store great quantise of fat to provide energy for the developing plant embryo. Three classes of lipids: triacylglycerides (tags, phosphatidyl choline. Properties of lipids: fatty acids are the simplest lipids, and they are also constituents of more complex liquids.
