Chemical Composition of Cells

891 Words4 Pages
CHEMICAL COMPOSITION OF CELLS BY OLADIWURA FAKIYESI BIOLOGY 101 LAB REPORT INTRODUCTION All cells contain four major types of macromolecules: carbohydrates, lipids, Nucleic acids, and proteins. Each macromolecule is a large polymer that is formed from constituent molecules known as monomers. Proteins, for instance, consist of a linear chain of amino acids joined together by peptide bonds (Murray et al., 2006). Carbohydrates are formed from monosaccharides and disaccharides joined together by glycosidic bonds (Varki et al., 2008). Lipids, such as fats and oils, are derived from glycerol combined with three fatty acids by ester bonds (G.P. Moss, 1976). And lastly, nucleic acids are composed of nucleotides; each of which contains a pentose sugar, phosphate group, and nucleobase (Mullis, 1993). In this experiment, three of the four macromolecules-- proteins, carbohydrates, and lipids will be studied. Various chemical tests can be used to detect the presence of each of these molecules. Most of the tests involve a color change visible to the eye. If a color change is observed, the test is considered positive. If the color change is not observed, the test is negative, indicating that a particular molecule is not present. In all the chemical tests we will be performing, we will also be using two controls. The negative control will be a sample of distilled water (which should not contain any macromolecules). For the procedure correlated to the detection of proteins, it is predicted that the albumin will contain traces of protein due to it being known to be present in egg whites (an excellent source of protein). In the procedure correlated to the detection of starches, it is

More about Chemical Composition of Cells

Open Document