$igure / 6 'bsorbance vs concentration graph. 7oncentration of unno!n /+/* 8 7oncentration of unno!n /+/** 8
mg+ml mg+ml
Di!c!!ion
9roteins are polymers made up of amino acids joined by peptide bonds. These peptide bonds have partial double bonds character and absorb light. These feature is also important in measurement of absorbency. "iuret reagent contains 7u: ion !hich form complex !ith peptide bonds of the protein. The "iuret method is not highly sensitive but it is the most linear because its colour depends on a direct complex bet!een 7u: and peptide bonds of the proteins. Thus, the colour may slightly different depending on the concentrations of the proteins. ' standard curve %$igure /( !as graphed using data from the five samples of no!n absorbance and concentration. 3nno!n solution /+/* and unno!n solution /+/** have absorbance of *.--20 and *./*0 respectively, !hen ran through the spectrometer. These points are then plotted on the y;axis of the graph and a line is dra!n to the curve. The intersection of both points sho! the protein concentration of unno!n /+/* as mg+ml and unno!n /+/** as mg+ml.
Concl!ion
$rom the standard curve plotted using the data recorded in this experiment, it can be concluded that the amount of absorbance is directly proportional to the concentration of proteins. In other !ords, the higher the concentration of protein, the higher the level of absorption. 'lso, it is dependant on the amount of !ater in the solution. When the amount of !ater increases, the concentration !ill decrease, thus the absorbance !ill also decrease. "y using the standard curve from data of this experiment, it is easier to determine the concentration of unno!n protein solution by first determining its level of absorption.
