1. Biological Molecules
-Biological molecules consist primarily of carbon, oxygen, hydrogen, and nitrogen.
-These elements share valence electrons to form bonds so that they have electron configurations like those of a noble gas element.
-Since there are so combinations of carbon, nitrogen, oxygen, and hydrogen, it is possible to form many compounds from just these few elements.

2. Biological Molecules
-Biological molecules, such as proteins, nucleic acids, and starch, are made up of various combinations of a small number of subunits.
Examples:
carbohydrates (bread, pasta) – sugars
proteins – amino acids
DNA – nucleotides

3. Biological Molecules
-Proteins are long chains (polymer) made up of many small subunits called amino acids. Bonds between amino acids are called peptide bond, is identical for any pair of amino acids.
-Different proteins have different amino acids and are ordered in different ways which determines their function.

4. Biological Molecules
-DNA determines how protein molecules are made and biotechnology is a career field that studies DNA, amino acid sequences, and the shapes and functions of proteins.