Testing foods for proteins, lipids, sugars and starch. Aim: To test a variety of foods for various substances
Testing foods for proteins, lipids, sugars and starch.
Aim: To test a variety of foods for various substances.
Introduction:
Proteins are large molecules which are made from a chain of amino acids. There are 22 different amino acids which can be found in proteins. Nine of these are classified as essential because they cannot be manufactured in the body and need to be acquired through the food we eat. The remaining 13 are classified as nonessential and can be manufactured by the body from other substances.
Carbohydrates need to be broken down into sugars for them to be used as energy. Sugars are in carbohydrates: this means that they contain the elements Carbon, Hydrogen and Oxygen, and that there is twice as much Hydrogen as there is Oxygen. Hydrogen and Oxygen atoms are in the ratio of two to one as in water molecules. The simplest sugars are called monosugars or monosaccharides.
Starch is made by plants as a way of storing chemical energy; starch comes in two common forms. Amylase is believed to be a long, unbranched chain of alpha-glucose molecules, in which the fourth carbon atom of one sugar is joined to the first carbon atom of the next sugar. The second form is Amylopectin a branched series of glucose chains.
Lipids are made from one glycerol and three fatty acids. Cells break down fatty acids. It can also break down simple sugars. Fatty acids release about twice the energy of an equal amount of simple sugars. Lipids are energy rich organic compounds. Which is made of carbon, hydrogen, and oxygen. Lipids contain even more energy than carbohydrates. One of the lipids is cholesterol. Cholesterol is an important component of animal cell membranes.
