1. The Chemical Evolution The molecules we know today are descended from the first molecules that formed life on Earth. The behavior of today's biological molecules reveals clues about their potential roles in the origin of life. Earth’s Primordial Environment  Present atmosphere

2. Aim: What is the structure of RNA ? Every living thing is descended from its ancestors. Evolution results when changes occur along the way. At a molecular level, the same idea applies. Each genetic information molecule must be copied and passed on to future generations. These molecules also evolve when they are changed along the way.

3. RNA is a polymer made up of four repeating subunits called nucleotides. Each nucleotide contains a sugar, a phosphate group and a nitrogenous base.

4. Atom  Element  Compounds Living things are made from organic compounds (C, H, O, N, S, P and other elements in minute amounts) Organic Compounds Carbohydrates – sugar, starches Proteins – enzymes & structural proteins Nucleic Acids – RNA, DNA Lipids - fats

5. Nucleotides in RNA are made up of a sugar, phosphate and base

6. Structure of DNA and RNA