35 Amino acids are joined in a protein by the formation of a peptide bond + H 3 N C C N C C O - + H 2 O H R 1 H R 2 O O H + H 3 N C C O - + + H 3 N C C O-H R 1 H R 2 O O Peptide (amide) bond Dipeptide â contains two amino acid residues planar. 36 20 amino acids can form 20 2 or 400 dipeptides.
Hydroxylapatite, also called hydroxyapatite (HA), is a naturally occurring mineral form of calcium apatite with the formula Ca 5 (PO 4) 3 (OH), but is usually written Ca 10 (PO 4) 6 (OH) 2 to denote that the crystal unit cell comprises two entities.Hydroxylapatite is the hydroxyl endmember of the complex apatite group.The OH â ion can be replaced by fluoride, chloride or carbonate, producing fluorapatite or chlorapatite. It crystallizes in the hexagonal crystal system.ydroxylapatite is the hydroxyl endmember of the complex apatite group. The OH â ion can be replaced by fluoride, chloride or carbonate, producing fluorapatite or chlorapatite. It crystallizes in the hexagonal crystal system.
Calcium is used to produce the minerals contained in bones, shells and teeth through a process called biomineralisation. Calcium phosphate (also known as hydroxyapatite) is the mineral component of bones and teeth and is a particularly good example of how organisms fabricate 'living' composite materials.alcium was named after the Latin term calx meaning lime, and is a reactive silvery metallic element found in Group 2 of the periodic table. It was first isolated in 1808 in England when Sir Humphry Davy electrolyzed a mixture of lime and mercuric oxide.