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