Proteins

Enzymes: Chapter 6

* Enzymes are biocatalysts (catalyst: substance that increases the velocity or regularize of a chemical reaction without itself undergoing any change in the overall process) synthesized by living mobile phones
* They are protein in genius (exception-RNA acting as ribozyme), colloidal and thermolabile in quotation and specific in action
* Example: laboratory hydrolysis of proteins by bullnecked acid at 100 deg. takes at least a duette of days. The same protein is fully digested by enzymes in the gastrointestinal tract at body temperature (37 deg) within a couple of hours.





Historical Background

* Berzelius in 1836 coined the term catalysis (Greek: to dissolve)
* 1878 Kuhne used word enzymes (Greek: in barm) to indicate the catalysis taking place in the biological systems
* 1883 closing off of enzyme system from cell-free extract of yeast was conduced by Buchner, who named active principle as zymase (later found to need mixture of enzymes) which could convert sugar to alcohol
* James Sumner first achieved the isolation and crystallization of the enzyme urease from jack bean and identified it as a protein

Nomenclature and Classification

* Early days: enzymes given names by their discoverers in an arbitrary manner and gave no information or so the function of the enzyme (trypsin, pepsin)
* -ase was sometimes added to enzyme name (lipase acts on lipids) and were known as trivial names, which also failed to give complete information on enzyme reaction
* Enzymes are considered under to broad categories
* Intracellular enzymes: utilitarian within cells where they are synthesized
* Extracellular enzymes: active outside the cell; all the digestive enzymes belong to this group
* International Union of Biochemistry (IUB) establish an Enzyme Commission in 1961
* Committee mad a native study of existing enzymes and devised some basic principles for the classification and language of enzymes...If you want to get a full essay, order it on our website: Orderessay



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