The Use of Enzymes in Biotechnology.

Felice Cartz

Mrs Naranthera

The Use of Enzymes in Biotechnology

Enzymes are biological catalysts, which are able to speed up chemical reactions without changing their conditions. They work on compounds called substrate molecules, and can either break them down (catabolic reactions), or join them together to make new molecules (anabolic reactions). Enzymes lower the activation energy of a reaction, meaning that less ATP is required for it to take place. It is this which speeds up the rate of the reaction. Enzymes are globular proteins, which explains why they have a distinctive tertiary structure. Each enzyme has a different shape and forms a pocket known as the active site, which is where the substrate molecule binds. The shape of the substrate must compliment the shape of the active site, in order for it to function. This idea was put forward by the theory of induced fit.

There are many different factors which affect enzyme activity, a significant one being the effect of temperature. An increased temperature provides more heat and kinetic energy to the particles within the reaction, which makes them move faster. This results in an increase in the number of collisions between enzymes and substrate molecules, meaning that more of the desired product will be made in less time. Other factors which affect enzyme activity include pH levels, substrate concentration and enzyme concentration.

Using enzymes can be very advantageous. They are specific to their reactions, which prevents the creation of unwanted products and they don’t require extreme conditions in order to work, therefore reducing costs. In addition to this, enzymes are biodegradable and subsequently have a less damaging effect on the environment. These reasons explain why enzymes are so widely used in industry; the main ones being in the production of dairy & alcoholic products, leather and biological washing powders.

The food industry is probably the most unknown to the public which uses enzymes. They are used for a number of ...

This is a preview of the whole essay

The food industry is probably the most unknown to the public which uses enzymes. They are used for a number of things including enhancement of flavour, aroma and texture, improvements to appearance, removal of unwanted flavours and other defects. The most used enzyme within the food industry is protease. This specific enzyme is responsible for the hydrolysis of peptide bonds of proteins, and is a vital substance in our bodies as it aids with digestion. An example of how protease works is visible within the baking industry; protease is used to reduce the protein content in flour for the increased production of biscuits.

There are numerous different forms of proteases, one example being rennet which is traditionally used in the production of cheese. The rennet breaks up the peptide bond present in the κ−casein protein in milk. The breaking down of this bond allows the milk to coagulate, and therefore curd to made cheese. Rennet is obtained from the stomachs of calves, and is subsequently quite expensive. Because of this, attempts to find cheaper alternatives using microbial sources are constantly being made.

Endogenous proteases are used on meat both to enhance flavour and to tenderise it. Dormant papain is injected into the animals prior be slaughtering which rapidly kills the animal. The enzyme accumulates in the muscles, which causes the meat to tenderise. This method of slaughter is however not favourable for the reason that it destroys the animals heart, liver and kidneys that otherwise could be sold.

When producing fruit juices, enzymes can be used to either maximise the production of clear or cloudy juice. The presence of natural pectins (polysaccharides) in non-citrus fruits such as apples and berries, are what cause hazing in their subsequent juices. To prevent this undesired cloudiness, pectin degrading enzymes are added to the juice at the pulping stage. The enzymes not only prevent haziness, but increase the yield of juice by reducing the viscosity of the solution. However, when producing citrus fruit juices such as orange juice, the opposite effect is desirable. Pectin methyl esterase is used to promote cloud formation by increasing the assembly of pectin.

Another industry that uses enzymes, possibly unbeknown to the public, is the detergent industry. Since the 1960s enzymes have been used to enhance the performance of biological washing products. Protease is once again a highly used enzyme in this particular industry. It can eradicate organic stains including sweat, blood and mud. In more recently years, however, lipases and amylases have also been used as they remove stains derived from fatty and starchy products respectively. Detergents are constantly being improved so that clothes are less vulnerable when washed. Cellulases are often used in washing powders to prevent fading of colours and “bobbling”. These enzymes remove detached fibres from the fabric this preserving the original brightness of the colour.

It is clear that enzymes are used extensively in biotechnology today, but will this continue to be the case in the future. Due to the fact that enzymes are not widely available on a large scale, industries are trying to seek out new enzymes in their natural environments as well as using them in as many ways that is possible. However it is becoming more and more common for enzymes to be genetically engineered. This not only increases the availability of existing enzymes, but allows for the creation of new ones.

Bibliography:

A New Introduction to Biology – Indge, Rowland & Baker

Heinemann Advanced Science; Biology – Fullick