Biological Catalysts And Metabolic Reactions Biology Essay

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Enzymes are biological catalysts that alter the speed of reaction (1), without themselves undergoing a permanent change (3). All metabolic reactions are catalysed by enzymes (1). Enzymes are large precise three dimensional globular proteins with a specific active site. The active site can only change one type of substrate molecule which has the same shape of the active site. (2). The active site has a similar shape as its substrate molecule, thus allowing the substrate molecule to perfectly fit into itself. The bonds such as R group and the amino acids (2) between the large substrate molecule are broken,

Pulling the substrate out of shape and making a product (2) which is know as enzyme- substrate molecule (1). This is also known as the lock and key theory (). However, recently scientists have discovered a another theory which is fairly practical theory that the active site do not have the same shape as the substrate molecule but it temporarily

changes its shape according to its substrate molecule due to some chemicals produced by the substrate molecule (4).

As enzymes are proteins, they have certain properties. Enzymes get denatured at temperatures above 35-37°C(5). Typically almost all reactions speed up with a raise in temperature. However with enzymes this theory does not work. At low temperatures the rate of enzyme reaction is slow this is because the substrate molecules do not often collide with the active site (2). As temperature increases the rate of reaction also increases due to more often collision of the substrate with the active site. This breaks the Hydrogen bonds in the enzyme which results in a change of shape of the enzyme molecule (1).

Graph of effect of temperature graph of effect of pH on enzymes. Enzyme inhibitors are molecules that interact in some way with the enzyme to

prevent it from working in the normal manner. There are a variety of types of inhibiters including: nonspecific, irreversible, reversible -competitive and non-competitive.

Most reaction catalyzed has commercial uses enzymes were not used, the contents were heated or strong acids were added. However after the introduction of enzymes in the industries, they have been enjoying many benefits out of it. As enzymes are very specific, by- products are less likely to be produced. Enzymes are also biodegradable so less environmental pollution is caused. A lot of energy is saved as enzymes work at neutral pH, atmospheric pressures and low temperatures. However if all these conditions are not maintained properly enzymes can be denatured. Industries such as cheese industries, biological washing powder industries, bread industries, leather industries, beer industries, baby food industries etc highly depend on enzymes for making their products. Due to this they have to extra c.areful in controlling the conditions so as the enzymes can work effectively.

Biological washing powders contain enzymes well as detergents which make the biological C powder more effective then the non-biological

powders. The detergents help to make the greasy soluble in water so as it can be washed away. The breakdown other kind of substances which can clothes. They breakdown large molecules.I the substances into small molecules which can be soluble in water. plus,FAB, Breeze, Dynamo

There are different kinds of enzymes in the biological powder. There are proteases, amylases and lipases in the washing powder. Lipases catalyses the breakdown of

Into fatty acids and glycerol. Amylases breakdown starch

to glucose molecules so as they can be dissolved in .Proteases catalyses the breakdown of proteins to amino

In addition the enzyme cellulose is also added to in the so as to smoothen the fabrics in the cloth.

The structure of protease has at least three levels of molecular structure, some might also have four. The first one is the primary structure where by the amino acids are bonded together by peptide bonds.

The secondary structure is when the peptide bonds bends into a certain form, producing a coil shape in space, resulting in alpha helix or folding produces a sheet, which is know as the beta sheet. Between the peptide bonds, hydrogen bond holds the structure in its shape

The tertiary structure is its 3 dimensional shape .u proteases the peptide bind bend in different ways (5) Normally. the hydrophilic .heads are on the outside of the structure making It soluble m water. This structure contains many different bonds such as covalent bonds, ionic bonds, disulphide bonds. The covalent bond forms between the R chains and disulphide bond between two amino acids.

Quaternary structure is formed when two or more peptides are present in the same

Active site of an enzyme is a 'dent' which has the same size and shape as its substrate which changes polymers into monomers. In this case proteases change proteins into amino acids.

Biological washing powders use the enzyme protease. This k enzyme is used to break down protein stains for example food and blood. The enzymes need alkali conditions to work the best and the detergents provide this. And as the enzymes work at relatively low temperatures this means the washing machine does not have to work at high temperatures. This is also environmental friendly.

To be effective in a production process the enzyme molecule must be brought into maximum contact with the substrate molecules. The solutions can be mixed in suitable concentrations or immobilization of the enzyme may be used. This involves attaching the enzyme to an inert surface such as plastic beads and then bringing the surface into contact with a solution of the substrate. Immobilization has the advantage that the enzyme molecules can be used over and over again, with the result that a lot of product can be made from a relatively small amount of enzyme.

Proteases are obtained from both animal and plant tissues, but now proteases are also being produced on a large scale in industries. Most enzymes come from bacteria which live in hot springs. So this means these proteases can work at high temperatures as well as low temperatures. These enzymes can work at or around 45°C. Mostly these enzymes are produced using bacteria and fungi. This is because these microorganisms grow and reproduce fast in bulk fermenters. The artificial enzymes become isolated.

These artificial isolated enzymes in industries cannot be used again, this can be disadvantageous. So manufacturing of this enzyme becomes costly. However the alternative immobilized enzymes, which is attached to the fibers or held in granules, are attached in the passage area of the substrate. By these enzymes, industries benefit the cost of producing new enzymes as they can be reused.

Its is suspected that biological washing powders triggers the eczema, which results in allergies. Many workers in the biological washing powder industries have been suffering from these allergies. But it is still debated. As eczema is heritable disease many people do not opt to use biological washing powders.