Focus Area 2

Main groups of substancesInorganic Substances (these substances do not contain carbon)

Organic Substances (these substances contain carbon)

MineralsWaterOxygenIronCalciumSodium

CarbohydratesLipidsNucleic Acids

Carbohydrates• The most common form of organic compound• All carbohydrates contain carbon. Hydrogen and oxygen atoms.• Their role is to supply living organisms with energy• Carbohydrates are stored in the form of starch in plants and as

glycogen in animals

• From these storage molecules, carbohydrates can be broken down into simplier and more useable forms such as glucose.• Carbohydrates also play a role in cell structure. Cellulose is a

carbohydrate and is the main component of plant cell walls

Lipids• Lipids contain hydrogen, carbon and very few

oxygen atoms• They are a more efficient energy molecules then

carbohydrates however they are a secondary source• Long term storage of energy• Fats and oils are examples

• Act as insulation for the body, protect internal organs• Help in the absorption of some minerals• Form an important structural part of all membranes in cells• Some act as essential structural parts of hormones which are

chemical messengers (steroids)

Proteins

• Contain carbon, hydrogen, oxygen and nitrogen• Long chains of amino acids• Used in structure, storage,

movement and transport of cells• Examples of proteins are

hormones and antibodies• Enzymes are proteins that speed

up chemical reactions

• Proteins are made up of amino acids• There are 20 different amino acids

Nucleic Acids• Contains the elements carbon, hydrogen, oxygen, nitrogen and

phosphorous• The heredity information found in the nucleus of your cells• DNA stands for: deoxyribonucleic acid• RNA stands for: ribonucleic acid

• Made of nucleotides, linked together to form single chains (RNA) or double strands (DNA). Each is made up of a simple sugar, a phosphate and a nitrogen base.

• DNA stores the information that controls the cell and therefore the whole organism• DNA is responsible for transmitting inherited information from one

cell to another• RNA is a nucleic acid found in small amounts in the nucleus but in

larger amounts in the cytoplasm.

VIDEO• https://www.youtube.com/watch?v=YO244P1e9QM

Movement in and out of cells• What are some substances that need to enter and leave the cell?

Model of the Cell Membrane