Organic compounds contain the elements carbon and hydrogen. They can have other elements, but, to be an organic compound, they definitely have those two. Important ones to know in biology are sugars and starches which are known as carbohydrates, proteins, lipids, nucleic acids. The term monomer means a simple molecule, or a component of a more complex molecule called a polymer. For example, glucose is a monomer--it's a simple sugar with the formula C6H12O6. It is called a monosaccharide, or single sugar. The ratio of Hydrogen to Oxygen atoms is 2:1. This holds true of all carbohydrates. If two glucoses are joined together, by the process called dehydration synthesis, a disaccharide forms. When many sugars are joined together, a polysaccharide forms. The prefix poly refers to "many". Starch is a very important polysaccharide which is an energy storage compound in plants. Proteins are important organic compounds as they are found in the cell membrane, muscles, bones, enzymes and hormones. They consist of smaller units known as amino acids, consisting of carbon, hydrogen, oxygen, nitrogen and sometimes sulfur. When several amino acids join together, a polypeptide forms. These amino acids are held together by peptide bonds. When this long chain of amino acids folds into a 3 dimensional shape, a functional protein is the result. Lipids, which are fats, oils, and waxes, are made of fatty acids and glycerol. These consist of the elements carbon, hydrogen and oxygen, however, the H:O ratio is not 2:1, as in carbohydrates, but is much higher. Nucleic acids are large molecules, made of smaller units called nucleotides. Two important nucleic acids are DNA the hereditary material of the chromosomes and found in the nucleus and RNA, found in the nucleus and cytoplasm. Carbohydrates, Proteins, Lipids and Nucleic acids are all important organic compounds in biology.