Bond To The Active Site Of Enzymes example essay topic
Enzymes are catalytic proteins; therefore they change the rate of a reaction without being consumed. This means that once and enzyme does its job it can still perform the same function as it did before. Organic catalysts change the rate of a reaction without being permanently changed. Enzymes are polypeptides that are made up of amino acids. Enzyme variable groups that are exposed are the places in which biological processes take place. These side chains, commonly called 'R groups,' make up the active site and catalyze the conversion of the substrate to make a product.
These side chains are often called variable groups because they are often what determines the kind of enzyme it is, therefore determining what substrates it will bond with. A change in temperature or a fluctuation in pH can alter the enzyme's structure. Anent temperature the alteration of the enzymes occurs when the temperature is very high and the enzyme denatures and is unable to perform the desired task. The temperature is so high that the active site of the enzyme changes and it is unable to bond with substrates. The pH at which different enzymes denature differs from enzyme to enzyme. Similar to too high a temperature, if a specific enzyme is at a pH at which the active site changes, the enzyme is unable to function.
This illustrates how the structure of an enzyme is vital to its proper functioning. Allosteric enzymes differ in structure than the previous enzymes addressed. The extreme temperature an dpH rules, however, still apply. Most enzymes are composed of two or more sub units, each having its own active site.
The enzymes are constantly changing between two conformational states, active and inactive states anent functioning. This oscillation helps in the regulation of the enzymes. Enzymes function as organic catalysts, meaning that they are organic molecules (proteins) that change the rate of reaction without being consumed by the reaction. Enzymes form weak bonds substrates to break them apart or bring them together to form bonds. The function of enzymes is to lower the energy (activation energy) required to break bonds. Bonds of substrates are needed to be broken in order to make the products; this process requires energy to break the bonds.
Enzymes speed up the process of converting substrates to products by lowering the required energy. Enzymes lower this energy by putting pressure on the bonds. The substrate induces the enzyme to slightly change its shape so that the active site fits more snugly around the substrate; this induced fit brings chemical groups of the active site into strategic positions that enhance the enzyme's ability to perform its function of catalyzing the chemical reaction. Enzymes may also function by providing a the substrate which a particular type of reaction.
For example, near the active site of an enzyme there may be specific side chains that aid in the transferring of specific elements to the substrate that are critical steps in catalyzing the reaction. Many enzymes require co factors, non-protein helpers, for catalytic activity. These co factors may be bonded permanently bonded to the active site or may bond loosely with the substrate. If the co factor that aids in the functioning of the enzymes is an organic molecule, it is more specifically called a coenzyme.
Most vitamins are coenzymes or are raw materials of coenzymes; therefore vitamins help in the functioning of enzymes. The operation of each enzyme and metabolic pathway is tightly regulated, either by inhibitors or activators. Inhibitors can covalently bond to the active site of enzymes, in which case the inhibition is irreversible, if the inhibitor is bonded with weak bonds the inhibition is reversible. Competitive inhibitors compete for the active site of the enzyme, hence the name. These inhibitors may resemble the enzyme and bind to the active site, blocking the substrate from bonding with the enzyme, thus reducing the productivity or the enzymes. Noncompetitive inhibitors inhibit reactions to occur by binding to a part of the enzyme other than the active site.
The interaction of this inhibitor and the enzyme causes the enzyme to change its shape, rendering the active site unable to receive substrates and make products. Allosteric enzymes also have specific ways to regulate enzymatic functioning. While the enzymes oscillates from its active and inactive form inhibitors or activators may bond to the sites. The binding of an activator to the site while the enzyme is in active form will allow the enzyme to function, the binding of an inhibitor to the site while the enzyme is in the inactive form will impede the ability of the enzyme to function. Cooperativity is when a substrate binds to the active site of an enzyme thus leaving the enzyme inactive form and aiding in the binding of other enzymes to the other active sites of the enzymes.
Feedback inhibition occurs when a metabolic pathway is turned off by the end product of the reaction. For example, the end product of a specific reaction maybe an inhibitor to the specific enzyme that makes the product; this prevents the enzyme to make more products when they are not needed. As the product accumulates the product slows down the synthesis or products. In conclusion, the structure of the enzyme is mainly dependent on the active site and variable groups.