Biological Molecules Breakfast Lab 2008-2009

Abstract

The purpose of this lab is to find and test various types of organic molecules including proteins, lipids, and carbohydrates in common food products. Characteristics of organic molecules will be made evident by using different procedures and stains to identify the macromolecules.

Introduction

Can organic molecules be found in food? The chemistry of living systems is the chemistry of carbon-containing compounds. Carbon's unique chemical properties allow it to polymerize into chains by dehydration synthesis, forming key biological macromolecules such as: proteins, lipids, carbohydrates and (nucleic acids).

Proteins perform the chemistry of the cell. Proteins are linear polymers of amino acids. Because the 20 amino acids that occur in proteins have side groups with different chemical properties, the function and shape of a protein are critically affected by its particular sequence of amino acids. Proteins are typically characterized as fibrous or globular.

Lipids are not soluble in water. Fats are one type of water-insoluble molecules called lipids. Fats can be saturated, like animal fat or contain unsaturated fats like margarines and oils. Fats are molecules that contain many more carbon hydrogen bonds than carbohydrates and, thus, provide a more efficient form of long-term energy storage. Other lipids include phospholipids and steroids.

Carbohydrates contain many carbon hydrogen bonds. Carbohydrates consist of monosaccharides or polymers of monosaccharides, and are used principally for energy, which is stored in their carbon-hydrogen bonds. The most metabolically important carbohydrate is glucose, a six-carbon sugar. Organisms often transport sugars as disaccharides and therefore, cannot be utilized wile they are being transported. Excess energy resources may be stored in complex sugar polymers called starches (in plants) and glycogen (in animals and fungi). The hypothesis is that if proteins, lipids, and carbohydrates are found in basic food produces, then they will be indicated as such using specific stains.

The following pictures are showing student extracting and indicating monosaccharides and polysaccharides from common jelly and bread:

A few here are using their own enzymes (salivary amylase) to break down starch by

chewing the bread for 2 minutes…Mmmmmmmmmm - good !