PHYSICAL PHARMACEUTICS

Physical Pharmaceutics



Physical Pharmaceutics

INTRODUCTION

Enzymes, proteins that act as catalysts, are the most important type of protein. Catalysts speed up chemical reactions and can go without being used up or changed without enzymes, the biochemical reactions that take place will react too slowly to keep up with the metabolic needs and the life functions of organisms. Catecholase is a reaction between oxygen and catechol. In the presence of oxygen, the removal of two hydrogen atoms oxidizes the compound catechol, as a result of the formation of water. Oxygen is reduced by the addition of two hydrogen atoms, which also forms water, after catechol is converted to benzoquinone. Long branched chains, the structural backbones of the red and brown melanoid pigments that cause darkening, are formed when the benzoquinone molecules are linked together.

Enzymes have a three-dimensional structure that is very complex. This three-dimensional structure consists of one or more polypeptide chains. These polypeptide chains form an active site, an area into which the substrate will fit.

There are four factors that will have an effect on the structure of an enzyme's active site, the activity of the enzyme, and the rate of the reaction in which the enzyme is involved. The four factors that can affect the activity of an enzyme include temperature, pH, enzyme concentration, and substrate concentration.

In the effects of temperature on enzyme activity, the rate of an enzyme-catalyzed reaction increases at temperature increases, up to the point at which the rate is its maximum. Most enzymes active in living tissue becomes denatured, their secondary or tertiary protein structure breaks down, at the temperature above 40°C.

In the effects of pH on enzyme activity, the way a protein folds can be changed in the presence of various ions that can interfere with the pattern of positive and negative charges within a protein molecule . In result, the shapes of the enzyme's active site may be changed. It is expected that the changes in pH would have an effect on the action of enzymes. In this case, optimum pH is the most favorable pH value because it is the point at which the enzyme is most active. Not only can denaturation be brought on by extremes in temperature, extremely high of low pH values can result in a complete loss of enzyme activity.

In the effects of enzyme concentration, an enzyme-substrate complex is formed when a substrate fits into the active of an enzyme. The reaction rate that the enzyme has with the chemical reaction is usually directly proportional to the enzyme concentration. Then, a product is formed. If the substrate is present in excess amounts, the reaction rate will increase in proportion to an increasing enzyme concentration, so that the available substrate does not limit the rate of reaction.

In the effects of substrate concentration on enzyme concentration, the velocity, the rate of speed, at which the enzyme works will increase until it reaches a maximum. This is only possible if the amount of enzyme is kept ...