A2 - How Genes Produce Proteins?

DNA is composed of building blocks known as nucleotides. Each nucleotide is made up of a sugar, a phosphate, and a base group.

The nucleotides are identified by the following bases: adenine (A), thymine (T), cytosine (C), and guanine (G). These bases pair together to form a double-stranded DNA molecule. Adenine pairs with thymine.

Cytosine pairs with guanine.

The order of the nucleotides in DNA is the code that carries information about which proteins the cells should build. During replication, cells make copies of DNA molecules before they divide to form new cells. During normal cellular functioning, the information in DNA is copied to a molecule called ribonucleic acid, or RNA.

A type of RNA called messenger RNA carries the information copied from DNA in the nucleus to the ribosomes located in the cytoplasm of the cell. This process is known as transcription.

At the ribosome, the RNA’s message is translated into a protein. The process of making proteins from RNA is called translation. When RNA is used to build a protein, the specific sequence of bases encodes a specific protein. If the sequence of bases is transcribed or translated incorrectly, the protein may not function properly. The types of proteins your body makes determine your traits.