Within each of our cells, there is a set of 23 chromosomes which encodes our unique genetic “blueprint”. Each chromosome consists of two long strands of DNA linked together to form a double helix. The basic building blocks of the DNA are nucleic acids (aka “bases”) of which there are 4: adenine (A), cytosine (C), guanine (G), and thymine (T). Each base links to the opposing base (A with T, C with G) on the other strand, thereby forming the double helix. A gene is a segment of DNA which has a certain sequence of base pairs to encode protein. Each gene contains regions of nucleic acid (exons) separated by non-coding DNA (introns). DNA is first transcribed into RNA, which has 4 bases; 3 are the same as DNA (A, C, G) but T is replaced by uracil (U) and the sugar (ribose) has an additional hydroxyl (OH) group. The RNA then undergoes processing prior to being translated into proteins. During translation, every 3 bases along the strand of RNA are read by transfer ribonucleic acid (tRNA) and encode for an amino acid. As the RNA is translated, an additional amino acid is added to the chain, which further elongates and becomes a protein. HnRNPU has 825 amino acids.
More information on DNA and genetics can be found at www.genome.gov