Proteins & Nucleic Acids Proteins make up around 50% of the bodies dry mass and serve many functions in the body including: – Enzymes - Catalysts that selectively speed up chemical reactions – Storage – Defense against foreign substances – Structural components – Transport molecules – Movement (Muscles) – Cellular communications

Proteins Proteins are made of one or more polypeptides made from 20 amino acids. – All amino acids contain the same backbone with amino and carboxyl side groups and differ only in their functional groups (-R). – The carbon in the middle is called the  carbon. Attached to it is the a hydrogen atom and -R. The side chains determine the individual characteristics of an amino acid

Peptide Bonds Bonds between amino acids are called peptide bonds and are formed via dehydration synthesis. – A union of many amino acids forms a polypeptide

4 levels of protein structure primary - sequence of amino acids secondary - b pleat or a helix tertiary - 3D structure aided by the formation of H- bonds, Van der Waals interactions (hydrophobic attraction), & disulfide bridges (-S-S-) quaternary - 2 or more polypeptides wound into one macromolecule.

Nucleic Acids Macromolecules containing C, H, O, N, P! Nucleic acids transmit and store Genetic information 2 basic types: – DNA (Deoxyribonucleic acid) – RNA (Ribonucleic acid)

Nucleic Acid Structure 3 parts – 5-carbon sugar makes up the backbone – Phosphate group – Nitrogenous base (AGCT or U)