amino acid 3

Amino acids used as a building block for hormones
Amino acids as a precursor for Thyroid Hormones
Amino acids are a precursor of building up a peptide neurotransmitters for example an enkephalin is a pentapeptide made from amino acids and involved in regulating nociception in the body. Responsible for pain sensation such as chili powder in the eyes.
Amino acids used as a building block for hormones such as insulin and glucagon Amino
Peptides and Proteins
- There are 20 amino acids commonly found in proteins and these differ from each other in the nature of the R-groups attached to the alpha
carbon.
- Proteins are organic compounds made up of chains of alpha amino acids linked together by peptide linkage [-C=(O)NH-].
This linkage is formed when the acid group (COOH) of one amino acid joins with the amine group (NH2) of a second amino acid through condensation as shown in the following scheme.
• ? compound containing two amino acids joined by ? peptide bond is specifically called ? dipeptide;
• Three amino acids in ? chain constitute ? tripeptide; and so on.
• The name oligopeptide is used to refer to peptides with 10 to 20 amino acid residues.
- The chains containing less than 50 amino acids and more than 20 amino acids are called “peptides”, while those containing greater than 50 amino acids are called “proteins”.
• Proteins:
Proteins are polypeptides that contain more than 50 amino acid units, average 350 for most proteins , some others up to 1000. Some proteins have molecular masses in the millions. Some proteins also contain more than one polypeptide chain
Protein Structure
• Proteins are macromo lecules and have four different levels of structure
• Primary,
• secondary,
• Tertiary and
• Quaternary.