1. Introduction a-Amylase catalyses the firststep in the digestion of starch, a main source of carbohydrate in the humandiet. Amylase that is present in human saliva was one of the initial enzymesever to be recognized. Starch is brokendown when mixed with saliva from a human. The agent that is in the saliva isresponsible for the chemical reaction that occurs. There are many aspects ofamylase and starch biochemistry that continually puzzle investigators includingthe full physiological significance of that familiar amylase in saliva. The beginning stage in the metabolism ofstarch is catalysed by a-amylase which progressively brings out hydrolysis ofthe polysaccharide resulting in the production of maltose, maltotriose andlimit dextrins as the main products.
In crystalline starch, the packing of thedouble helices are stabilised by hydrogen bonding between glucan residues. Eachglucan residue H bonds to various amino acid side chains that line the activesite. Therefore it can be expected that portions of polysaccharide chain thatare intimately associated in forming crystallines are unlikely to bind securelyto the active site. It is likely that crystalline regions contain a number ofregions where the crystals are imperfect to give ‘amorphous zones’ where thechains are capable of becoming H-bonded to active site residues of amylase.There would seem to be a high probability of damage to crystalline areas duringindustrial processing such as milling. If damaged areas are relatively few innumber, enzyme binding to these amorphous zones is not very likely unless theconcentration of amylase is high.
Knowledge of the structuresand properties of starch and a-amylase has increased significantly in recent years.This information is helping our understanding of the reasons for variations inthe rates at which starches from different botanical origins and/or fromdifferent starch foods are digested by amylase. A number of uncertainties stillremain, however, particularly with regard to the full physiological importanceof the products of amylase gene AMY1 and the evolutionary significance ofpossession of multiple copies of amylase genes. The choice of kinetic modelsfor studying starch amylolysis in vitro is also subject of some controversy. (Butterworthet al, 2018).Aim: To find out what effects amylase has in thereaction of iodine with starchHypothesis: There will be a difference in colourof the solution containing saliva.
2. Literaturereview An adequate supply of salivais critical to the preservation and maintenance of oral tissue. Cliniciansoften do not value the many advantages of saliva until quantities are lessened.A lot is written on the subject of salivary hypofunction, but little attentionis paid to normal salivary flow and function.
Saliva plays a vital role inmaintaining the health of the oral cavity and gastrointestinal tract by addingin lubrication, inhibiting potentially harmful microbes, and promoting oraltissue healing. Amylase is a digestive enzyme produced by the salivary glandsand pancreas that cleaves the glycosidic linkages in starch molecules toproduce smaller saccharides. Salivary amylase can account for up to 50% oftotal salivary protein in some individuals. Others produce barely detectableconcentrations. Such substantial variation in amylase production is due to bothenvironmental and genetic factors, such as copy number variation in AMY1, thegene that codes for salivary amylase.