Introduction To the Enzymes. Part#2
by Unknown
February 23, 2017
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So, I am back with 2nd part of my blog “INTRODUCTION TO ENZYMES.” Before starting the blog I would like to stat points of the last topic. In 1st part points covered were,
What are Enzymes?
Properties of Enzymes.
Structure and mechanism of enzyme action.
And now in this blog topics such as factors affecting rate of enzyme action, classification of enzymes, some examples of enzymes will be covered.
Factors Affecting rate of Enzyme Action
Some factors can affect the rate of enzyme action as they can affect the globular structure if enzyme and hence their specificity. Factors such as PH, temperature, the concentration of enzyme, and concentration of substrate can alter the rate of reaction.
Enzyme Concentration.
Rate of reaction no doubt depended on the concentration of the enzyme in presence if unlimited substrate concentration. If the concentration of enzyme is doubled the rate of reaction will also be doubled. This happens because increasing enzyme molecules increase the number of active sites. The more active site will convert more substrate to products in the given time.
Substrate Concentration
At low concentration of substrate, the rate of the reaction is directly proportional to the concentration of substrate. But a certain point reaches where a further increase in substrate concentration no longer increase reaction rate because all the active sites of enzymes are occupied.
Photo Credit ibbiologyhelp.com via article
Temperature
As temperature affects every reaction. Enzymatic reactions are also affected by the increase are the decrease in temperature as temperature provides energy for the reaction. The increase in reaction increases the rate if reaction by increasing kinetic energy of molecules but to a certain level. Every enzyme has its optimum temperature at which its work is maximum. For example, human enzymes act optimally at 37°C. Temperature above optimum temperature disturbed the globular structure of the enzyme hence decreasing the rate of reaction and vice versa.
Photo Credit Effect of PH.
Like optimum temperature, every enzyme has optimum PH value.
Optimum pH is a narrow range of PH at which enzyme function maximum. Slight change in PH can alter the ionization in the active site of the enzyme and it can also affect ionization of the substrate molecule. Under these conditions, the enzyme activity is decreased or blocked completely. The extreme change in PH level can denature enzyme configuration and destroy enzyme structure completely.
Optimum pH is a narrow range of PH at which enzyme function maximum. Slight change in PH can alter the ionization in the active site of the enzyme and it can also affect ionization of the substrate molecule. Under these conditions, the enzyme activity is decreased or blocked completely. The extreme change in PH level can denature enzyme configuration and destroy enzyme structure completely.
Photo Credit Classification of enzymes
Oxidoreductases
These enzymes catalyze oxidation-reduction reactions in which electrons are transferred.
Transferase
These enzymes catalyze reactions that involve group transfer. The transfer occurs from the donor to the acceptor. An example of these enzymes is Hexokinase used in glycolysis reaction.
Hydrolases
These enzymes catalyze hydrolysis reactions. This usually involves the transfer of functional groups from molecules to water. Chymotrypsin is an example of transferases.
Lyases
Lyases add functional groups to break double bonds in molecules and vice versa. For example Fructose-bisphosphate aldolase.
Isomerases
Isomerases transfer functional groups within a molecule producing isomeric forms. For example phosphoglucose isomerase.
Ligases
Ligases are used in reactions where two substrates are ligated.
Examples of some enzymes( some popular enzymes.)
lactase
lactase enzyme is produced by many organisms in their small intestine this enzyme helps in proper digestion of the milk in the intestine. It digests lactose a sugar present in milk. lactase is also available in the market. It can be added to milk for producing lactose-free food. Lactase is also used in medical treatment of intolerance of lactose.
Photo Credit Proteases
Protease enzyme is also produced by the organisms to digest proteins in their food. Protease performs breakdown of proteins in our digestive track. Proteases are classified in my classes that can perform similar functions.As proteases are themselves proteins that's why some proteases are degraded by other proteases.
DNA polymerase
DNA is hereditary material;l of living organisms and when one cell divides the DNA in also divided to pass parental information in the newborn cell. DNA polymerase enzyme carries out replication of the DNA molecule in our cell. So, DNA polymerase enzymes very important in the procedure of passing information from one generation to other generation.
Photo Credit Inhibitors
Substrate reacts with enzyme and is converted into products. But an inhibitor is a chemical substance that binds with enzyme but is not converted into products. Thus, blocks the active site if the enzyme temporarily or permanently, preventing substrate to react with the enzyme.
For example, Poisons, like cyanide antibodies, anti - metabolites, and some other drugs inhibit enzyme activity.
For example, Poisons, like cyanide antibodies, anti - metabolites, and some other drugs inhibit enzyme activity.
Classification of Inhibitors
Inhibitors are divided into two types depends on how they inhibit active site of the enzyme, temporarily or permanently.
Irreversible Inhibitors
These inhibitors permanently occupy the active site of an enzyme or destroy the globular structure if enzyme. They bind with active site forming covalent. So, permanently inhibiting the enzyme activity.
Reversible Inhibitors
Reversible inhibitors as clear from their name are temporary inhibitors and their effect can be decreased or neutralized completely by an increase in a concentration of the substrate.
These inhibitors are further devised into two types.
These inhibitors are further devised into two types.
Competitive Inhibitors
Their structure is similar to the substrate. So they compete with the substrate to bind to the active site. But when they are attached to active site blocks it and products are not formed. Increased concentration of the substrate can decrease the effect of competitive inhibitors.
Non-Competitive Inhibitors
There is no similarity of structure in non-competitive inhibitors and substrate. These inhibitors bind with the enzyme at the site other than active site but alter the structure of the enzyme that it can not form products even a substrate in attached to its active site.
That all I have to discuss with you people.I hope you will like and appreciate my work.
Keep smiling and stay blessed.
Introduction To the Enzymes. Part#2
Reviewed by Unknown
on
February 23, 2017
Rating: 5
Reviewed by Unknown
on
February 23, 2017
Rating: 5
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