Question

name one non-protein class of biological catalyst- What was it?

What are the classes of enzymes?

What are four advantages of biological catalysts over chemical catalysts?

General properties of enzymes

Compare and contrast with chemical catalysts

Answer 1

1. Ribozymes are non protein class of bological enzymes.

• Ribozymes are Ribonucleic acid(RNA) enzymes.

2. Enzymes can be divided upon SIX classes according to the type of the reaction they catalyze and the nature of the substrate involved-

• Oxidoreductases - Catalyzes Oxidation-reduction reactions
• Transferases - It is involved in Group Transfer reactions
• Hydrolases - Involved in Hydrolysis
• Lysases - Catalyze double bond formation reactions
• Isomerases - Involved in Isomerization reactions
• Ligases - Involved in addition of two compounds.

3. There are some natural advantages that the biological catalysts enjoy over their chemical counterparts-

• Chemical catalysts are Metals those have loosely bound electrons and they help the reaction to speed up by using these electrons,no partial bonding with the substrate take place here.On the other hand, biological catalysts are enzymes and these aid the substrate molecules to get fit into the active site and the enzyme drives the entire reaction thereafter.These enzyme kinetics are quantitatively described by the Michaelis-Menten equation.
• As enzymes are available inside the body (or available lifeforms),they generally do not need any specific optimum temperature as is the case with chemical catalysts.Reactions take place at body temperature with the biological enzymes.
• Also the chemical catalysts work under certain optimum pressure which is not the case of the biological enzymes
• Biological enzymes are characterized for their highly specific behavior to the substrates i.e. each enzyme is specified for a particular substrate only and it doesn't catalyze other type of substrates. This is not the case with the chemical enzymes.

4. General Properties of Enzymes-

• Enzyme are generally very Complex macromolecules
• Nearly all enzymes are Proteins (there are exceptions too as your very 1st question!!)
• Enzymes can catalyze biochemical reactions within the cell itself
• enzymes are very much Substrate specific in action
• being class of proteins,increase in temperature cause a decrease in the enzymatic activity
• Enzymes work under neutral pH region
• being proteins,enzymes also have the Primary,Secondary and tertiary structures among which the Tertiary structure has several pockets within it which acts as active site and aids the catalytic process.

5. Both Chemical and Biological catalysts (enzymes) have one similar property i.e. they are used to speed up the reaction and both the class of catalysts works under certain conditions.However they have some contrasting behavior to mention-

Properties	Enzymes	Chemical catalysts
Nature	These are High molecular weight complex Biomolecules	These are Metals with loosely bound electrons
specificity towards Substrate	Enzyme are substrate specific in action	Chemical catalysts do not maintain such specificity
Optimum Conditions	Enzymes do not require any high temperature to catalyze a reaction. At high temperatures,enzymes,being proteins in majority cases,tends to decrease activity.	These catalysts require an optimum temperature and pressure to get the Energy kick for the reaction.