Introduction Enzymes are biocatalysts of proteinous nature, which accelerate the rate of biochemical reactions but do not affect the nature of final product. Like catalyst the enzymes regulate the speed and specificity of reaction without being used up but unlike catalysts enzymes are produced by the living cells only. Like catalysts enzymes also influence the rate of biochemical reaction so that they can take place at a relatively low temperature. Thus the enzymes are known to lower the activation energy. In many cases enzymes initiate the biological reaction.
The term enzymes is derived from Greek word enzymes which means 'in yeast' because the yeast cells were first to reveal the enzyme activity in living organisms. The term enzyme was coined by W. Kuhne in the year 1878.
Properties of Enzymes Properties of enzymes can be classified into three groups:
Physical Properties of Enzymes The physical properties of enzymes are:
Chemical Properties of Enzymes There are two main chemical properties of enzymes:
General Properties of Enzymes General properties of enzymes are:
Chemical Nature of Enzymes All enzymes are proteins, but all proteins are not enzymes. However, there are some conjugated enzymes with a non protein moiety attached to the protein part of enzyme, which is called apoenzyme. The non protein part is known as co factor. If the co factor is of inorganic nature like potassium calcium, magnesium, manganese it is known as prosthetic group. Prosthetic group is generally tightly bound to the protein part of enzyme and it is difficult to separate it with simple method like diffusion. The enzyme with prosthetic group and apoenzyme is called holoenzyme.
If co factor attached to an enzyme protein is organic moiety like NADP, NAD, FAD, etc , it is called coenzyme. A co enzyme is generally loosely bound to apoenzyme and can easily be separated than prosthetic group. Co enzymes are heat resistant also.
Difference between apoenzyme and co-factor The difference between apoenzyme and co-factor are as follows:
Conclusiong So in this article you read about enzymes, their properties, chemical nature and comparison of apoenzyme with co-factor. You will read comparison of enzyme and catalyst, nomenclature of enzyme and biological significance of enzymes in enzyme part II .
Hakimuddin Kuwakhedawala is based in India with over 15 years experience as a teacher. Teaching and writing are his passion. Most of the articles of Hakimuddin are related to education, exam, environmental problems, etc.
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