enzyme | Definition, Mechanisms,Enzyme, Enzymes - an overview

 

ENZYMES

Enzymes are proteins that catalyze 

( i.e. speed up ) biochemical reaction

and are not changed during the     reaction.

The life of living organisms is a reflection of what is    going on in their bodies.

Metabolism is the set of biochemical reactions that occur in living organisms in order to maintain life.

These processes allow organisms to grow and reproduce, maintain their structure and respond to their environment.

Anabolism includes the biochemical processes in which larger molecules are synthesize.

Catabolism include the biochemical reactions in which are broken down.

 

So, energy is release din the catabolism and energy is consumed in anabolism.

In this way, the biochemical reaction are actually energy transfers.

Enzymes are crucial to metabolism because they act as biocatalyst and speed up and regulate the metabolic pathway.

The molecules at which enzymes act are called Substrate

Enzymes converts them into different molecules called Product

Activation Energy

ØAll chemical reaction require activation energy.

ØIt is define as the minimum amount of energy which is require to start a biological reaction.

ØThe need for the activation energy acts as barrier to the beginning of reaction.

ØEnzymes lower such barrier by decreasing the requirement of activation energy.

ØThus in the presence of enzymes, reaction proceed at faster rate.  

> Enzymes lower the activation energy in several 
    ways:

1: They may alter the shape of substrate and reduce
    requirement of energy for this change.

2: Some enzymes do so by disrupting the charge
    distribution of activation energy.

3: Enzymes may also lower activation energy by
    bringing substrate in the correct orientation to
    react. 

Categories of enzymes

1 : Intracellular enzymes : The enzymes work  inside the 

      cell. E.g. enzymes of glycolysis working  in the

      cytoplasm.

2: Extracellular enzymes: The enzymes work outside

     the cell e.g. pepsin enzymes working in the

      stomach cavity.