SBL1023

LAB 4 PROTEIN ANALYSIS INTRODUCTION Proteins are polymers of amino acids. Twenty different types of amino acids occur naturally in proteins. Proteins differ from each other according to the type, number and sequence of amino acids that make up the polypeptide backbone. As a result they have different molecular structures, nutritional attributes and physiochemical properties. Proteins are important constituents of foods for a number of different reasons. They are a major source of  energy , as well as containing essential amino-acids, such as lysine, tryptophan, methionine, leucine, isoleucine and valine, which are essential to human health, but which the body cannot synthesize. Proteins are also the major structural components of many natural foods, often determining their overall texture,  e.g.,  tenderness of meat or fish products. Isolated proteins are often used in foods as ingredients because of their unique functional properties,  i.e.,  their ability to provide de

LAB 5 LIPID ANALYSIS INTRODUCTION Lipid are another word for fat.A lipid is chemically defined as a substance that is insoluble in water and soluble in alcohol, ether, and chloroform. Lipids are an important component of living cells. Together with carbohydrates and proteins, lipids are the main constituents of plant and animal cells. Cholesterol  and  triglycerides  are lipids. Lipids are easily stored in the body. They serve as a source of fuel and are an important constituent of the structure of cells. Lipids include fatty acids, neutral fats, waxes and steroids (like cortisone). Compound lipids (lipids complexed with another type of chemical compound) comprise the lipoproteins, glycolipids and phospholipids. Lipids include fats, oils, waxes, cholesterol, other sterols, and most steroids. In the body, fat serves as a source of energy, a thermal insulator and cushion around Lipids are biologically important for making barriers (membranes of animal cells), whic