Biological Molecules
Carbohydrates are foods that contain sugar and starch
❖ They contain carbon
❖ They are found in all living things
❖ It provides energy and is needed for energy
❖ Provides raw materials for growth and repair
❖ Lipids
❖ Proteins
❖ All contain carbon, hydrogen and oxygen
Isomers have the same chemical formula but different chemical arrangement
Water is an important solvent
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Enzymes
Enzymes are biological catalysts.
Catalysts are substances that speed up the rate of chemical reactions but are not changed
by the reaction.
This is because the enzyme’s specific shape(substrate) bonds with the other molecules and
breaks them down faster
Enzymes are proteins
Proteins are specific molecules that are folded into a specific shape made of amino acids
The part of the enzyme where the reaction occurs is known as the active site
,The enzyme will become denatured in extreme PH and extreme temperatures
One enzyme is specific to one substrate molecule or type of molecule
The lock and key hypothesis states that the active site specifically matches the shape of the
substrate molecule
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Nutrients
Vitamin C
❖ Helps heal wounds and maintain connective tissue
❖ It comes from Citrus fruit and Leafy green vegetables
❖ Vitamin C deficiency leads to Scurvy
❖ The symptoms of Scurvy include bleeding gums, loss of teeth and tiredness
Vitamin D
❖ Helps maintain healthy bones
❖ Comes from eggs and oily fish
❖ Vitamin D deficiency leads to rickets and bone pain
Vitamin A
❖ Needed to maintain good vision, healthy skin and strong immunity
❖ It comes from dairy products and oily fish
❖ Vitamin A deficiency leads to Night Blindness, where it is difficult to see in dim light
Calcium
❖ Needed to maintain healthy bones and teeth, for normal blood clotting and to control
muscle contractions
❖ Calcium comes from dairy products and leafy green vegetables
❖ Calcium deficiency leads to weak bones and teeth, poor blood clotting ability and
muscle spasms
Iron
❖ Needed to produce Haemoglobin
❖ It comes from liver, red meat, beans, nuts and dried fruits
❖ Iron deficiency causes Anaemia
❖ People with Anaemia are tired and weak as their blood does not carry as much
oxygen
Water
❖ Two thirds of the human body is water
❖ Water comes from drinking it
Dietary Fibre
❖ Dietary fibre is indigestible material found in food
❖ It is found in fruits, vegetables and cereals
❖ Dietary fibre provides bulk, which aids peristalsis
❖ Lack of dietary fibre can lead to constipation