CHAPTER ONE
1.1 INTRODUCTION
The primary aim of this project is centered on the determination of the catalytic and specific activities of enzymes in fermentation of starch from maize. These enzymes are DIASTASE, MALTASE and ZYMASE. This determination study is made possible through certain unique properties which these collection of enzymes posses.
Speaking in concrete terms, ENZYMES serve as biocatalysts, speeding up chemical reactions. Like those involved with fermentation of starch. Enzyme molecules accelerate the rate of reactions, often by many orders of magnitude, thereby allowing the substance involved undergo a chemical breakdown.
Enzymes in fermentation of starch go about their work in an ASSEMBLY-LINE fashion, each enzyme performing a specific task at a particular stage of the fermentation process. For instance, the enzyme – MALTASE, breaks down MALTOSE into two isomeric fermentable sugars namely - Glucose and Fructose; thereby preparing another stage for another enzyme to act during the fermentation process. Enzymes in fermentation process, especially in starch; perform their work at blinding speed.
A single molecule of enzyme can catalyze thousands of chemical reactions per second. This is because enzymes in fermentation reaction particularly in starch have a marked ability to accelerate the reaction and also to promote the specific processes involved under the chemically mild conditions, which prevails in the fermentation process.
In all ways, these enzymes readily make essential physiochemical contributions to the fermentation process by virtue of their organized and involved three-dimensional structure, which reveals certain regions on the enzyme surface where small solute molecules or ions can bind reversibly. Such solutes are called LIGANDS; a term borrowed from ORGANOMETALLIC CHEMISTRY.
There may be many ligard-binding sites on the surface of an enzyme. But each site usually possesses the power to bind only a limited range of ligards, by virtue of the character of the site. The term “CHARACTER” is here used to cover not only the three-dimensional shape of the site but also its charge characteristics and to what degree it is hydrophobic or hydrophitic.
The character of a binding site is clearly a function of the amino acid side chains that are brought together there by the folding of the polypeptide chain. Enzymes are distinguished from other protein molecules by having ACTIVE SITES. The substrate binds at the active site of its enzyme in much the same way as other ligards might do, but once bound there, a chemical reaction ensures because of the special nature of the enzyme active site in respect to their catalysis and specificity in fermentation bio-process.
Maize is the most widely grown grain crop in the Americas, with 332 million metric tons grown annually in the United States alone. The kernel of maize has a pericarp of the fruit fused with the seed coat referred to as “caryopsis”, typical of the grasses, and the entire kernel is often referred to as the “seed”. The grains are about the size of peas, and adhere in regular rows round a white, pithy substance, which forms the ear.
1.2 AIM AND OBJECTIVES OF RESEARCH
The research is aimed at determining the activities and specificity of enzymnes in fermentation of starch from maize.
1.3 SIGNIFICANCE OF RESEARCH
This study will help to determine the content of starch and the activities and specificity of enzymes involved in starch biosynthesis