REFLECTION 13: INTRODUCTION TO ENZYMES

Hey fellow biochemians! Welcome back to my biochemistry blog! Today we will be moving on to the topic Enzymes, and this first blog post will be an introduction to enzymes. Happy Learning!

What are enzymes?

Enzymes are biological catalysts that speed up the rate of a chemical reaction without themselves being used up or altered. Enzymes are able to do this by providing an alternative pathway with lower activation energy.

What is the transition state?

As a chemical reaction proceeds the structure of the substrate changes into the structure of the products.  The transition state refers to the highest energy along the reaction coordinates. It is said to be more free in energy that the substrate or products. See image below.

Transitionstatechem114A

What is the activation energy referring to?

The activation energy refers to the minimum amount of energy required for a reaction to proceed. To speed up the rate of reaction as we said earlier the enzymes provide an alternative path with lower activation energy. By lowering the activation energy more substrate molecules are converted to products per unit time hence quicker reaction. See image below.

ch06c1

How are enzymes named?

Officially, there are six major classes in which enzymes are divided into. Within each class there are subclasses which consist of sub-subclasses whereby individual enzymes are listed. Six major classes of enzymes are as follows:

1.      Oxidoresuctases

2.      Transferases

3.      Hydrolases

4.      Lyases

5.      Isomerases

6.      Ligases

Please ensure, when learning these classes you learn them in order as it will be important when you are given an enzyme classification number and you are asked to identify which class the enzyme belongs to.

What are cofactors & coenzymes?

Cofactors– substances that cooperate with enzymes in catalysis

Coenzymes– organic, loosely bond cofactors that play accessory roles in enzyme catalyze reactions e.g. as a donor of a substance involved in the reaction

 

References:

Featured Image-

http://en.wikipedia.org/wiki/Enzyme

Images-

http://en.wikibooks.org/wiki/Structural_Biochemistry/Enzyme/Transition_state

http://163.16.28.248/bio/activelearner/06/ch6c1.html

Youtube- BiochemJM

http://answers.yahoo.com/question/index?qid=20080929093411AAn1dmm

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