1. Deoxyribonucleic acid (DNA): This is the genetic material found in most living organisms. It contains the instructions for building and maintaining an organism. DNA is a double-stranded helix, with each strand composed of nucleotides containing a deoxyribose sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T).

2. Ribonucleic acid (RNA): RNA plays a crucial role in protein synthesis. It's involved in copying the genetic code from DNA and carrying it to the ribosomes, where proteins are assembled. RNA is usually single-stranded and contains a ribose sugar instead of deoxyribose. It also has uracil (U) instead of thymine (T) as one of its nitrogenous bases.