DNA and RNA are essential molecules in all living organisms. DNA (deoxyribonucleic acid) consists of two long strands forming a double helix, made up of four nucleotide bases: adenine (A), thymine (T), cytosine (C), and guanine (G). These bases pair specifically (A with T and C with G) to store genetic information. RNA (ribonucleic acid) is typically single-stranded and plays a crucial role in protein synthesis. It contains the same bases as DNA, except that thymine is replaced by uracil (U). RNA can be classified into different types, including messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA), each serving unique functions in the cell.