Middle back pain is any type of pain or discomfort in the area between your upper and lower back. Health care professionals refer to this area as the lower thoracic area or lower thoracic spine. The upper thoracic area or upper thoracic spine makes up part of the upper back.
Amino Acids. Amino acids are the monomers of proteins. They have a positively-charged amino group on one side and a negatively-charged carboxyl group on the other. Attached to the central carbon is a variable group called the 'R' group. This group is different for each amino acid. There are 20 amino acids in human cells.
Structure of an Amino Acid. Amino acids are the monomers that make up proteins. Each amino acid has the same fundamental structure , which consists of a central carbon atom, also known as the alpha (Î±) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom.