These are fats and oils.
Fats are solid at room temperature while oils are liquid.
They are made up of carbon, oxygen and hydrogen atoms.
The structural units of lipids are fatty acids and glycerol.
Fatty acids are made up of hydrocarbon chain molecules with a carboxyl group (-COOH) at one end.
In the synthesis of a lipid, three fatty acid molecules combine with one glycerol molecule to form a triglyceride.
Three molecules of water are lost in the process.
This is a condensation reaction and water is given off.
Lipids are hydrolysed e.g. during digestion to fatty acids and glycerol, water is added.
Condensation = Glycerol + 3 Fatty hydrolysis Lipid + Water acids
Properties of Lipids
Essential and Non-Essential Amino Acids
Formation of Proteins
Functions of Proteins
As structural materials proteins-
As functional chemical compounds.
Examples are hormones and enzymes that act as regulators in the body.
Examples are haemoglobin that transports oxygen in the blood and myoglobin that stores up oxygen in muscles.
Contractile proteins - make up muscles, i.e. myosin and actin.
Proteins combine with other chemical groups to form important substances e.g. mucin in saliva.
Source of energy.
Proteins are a source of energy in extreme conditions when carbohydrates and fats are not available e.g. in starvation.
Properties of Enzymes
Naming of enzymes
Enzymes are named by adding the suffix -ase to:
Name of substrate that they work on e.g.
Factors Affecting Enzyme Action
KCSE BIOLOGY NOTES, SCHEMES OF WORK, OBJECTIVES, QUESTIONS AND ANSWERS
NUTRITION IN PLANTS AND ANIMALS: