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4.5. Enzymes

Enzymes

The metabolism is a series of chemical reactions that occur arranged in organisms in order to synthesize macromolecules from simple molecules, with the energy obtained the break chemical bonds of other macromolecules, reserve substances or foods.

As the substances that take part in these reactions are very stable, a lot of energy is necessary for this reaction to take place because if not, the reaction speed would be zero or too slow. This could be solved by increasing the temperature, but it could cause the death of the organism, so living beings use biocatalystsenzymes, which lower the activation energy necessary for the reaction to occur, thereby increasing its speed.

Animated image: Enzymatic reaction.

The enzymes meet both common laws for all catalysts:

  • They are not altered or consumed during the reaction.
  • They favor that the same amount of product is obtained in less time, without shifting the equilibrium constant so that more product is obtained.

Enzymes, unlike non-biological catalysts, have high specificity, act at room temperature, and achieve a one million to one trillion fold increase in reaction speed.

There are also other biocatalysts of a ribonucleoprotein nature called ribozymes, capable of catalyzing reactions of splicing of RNA segments.

Fundamental Ideas About Enzymes

The enzymes are specific biocatalysts that decrease the activation energy and increase the rate of metabolic reactions, joining the molecule that will transform the  substrate to form a new substance, the  product.

The two laws common to all catalysts:

  • They are not altered or consumed during the reaction.
  • They favor that the same amount of product is obtained in less time, without shifting the equilibrium constant so that more product is obtained.

Enzymes have great specificity.