Recognise the Characteristics of Enzymes and Their Involvement in Physiological Processes

All living organism depend on catalytic proteins called enzymes, these compound are responsible for metabolism and biochemical regulation of energy, there are millions of enzymes and hundreds of enzymes have been identified in the human body as well. All living system possess enzymes as vital components of the body, enzymes are found in all organisms.
Everyone has a natural pH balance in the body. Enzymes are complex proteins which speed up chemical reactions if this did not happen it would occur to slowly for us to survive.
They are involved in breaking down large molecules in to smaller ones or they can build up smaller molecules in to bigger ones.
Enzymes speed up chemical reactions but they aren’t changed by the reaction so they can be re-used. (www.herbs2000.com/)
Enzymes are biological catalysts and they are proteins.
Enzymes in the body help carry out various chemical functions like digestion of food, assist in the process of providing cellular energy, support the brain functions, repairing and healing processes within the body, breaking down toxins, detoxification of blood.
The properties of enzymes are that they reduce the amount of energy needed for molecules to react together
Two examples of enzymes are:

Digestive Enzymes Digestive enzymes are secreted by the body that helps in digestion of food. The names of enzymes that help in digestion are: •Amylase: This enzyme helps in breaking down carbohydrates. It is found in saliva, pancreas and intestinal juices. •Proteases: It helps in digestion of proteins. It is present in the stomach, pancreatic and intestinal juices. •Lipases: Lipases assist in digestion of fats. It is seen in the stomach, pancreatic juice and food fats. Amylase I and II are secreted by the salivary glands initially and then by the pancreas. They break the bonds between carbohydrate molecules and produce disaccharides and disaccharides. Amylase I is activated by chewing and convert starch to maltose. Amylase II is secreted only by the pancreas and carries on with the process that has been initiated with Amylase I.( www.ehow.com /) Pepsin is produced as a proenzyme pepsinogen by the chief cells of the stomach. It gets activated by the hydrogen in the stomach and produces hydrochloric acid at the same time. It breaks the bonds between amino acids in the proteins and produces short chain polypeptides. It also kills any pathogen that enters the body through food. Pancreas produces trypsin as a proenzyme trypsinogen. It works on polypeptides and proteins producing short chain peptides. It is also acts as an activating enzyme for other pancreatic proteinases. Chymotrypsin produced by the pancreas acts on proteins and polypeptides producing short-chain peptides. Food Enzymes Food enzymes are present in all raw foods like animal or plant products. The names of enzymes that are plant-based are protease, lipase, amylase and cellulase. They contain active units that help break down fat, proteins and carbohydrates in the body at the broadest range of pH within the body. They also help in maintaining a proper digestive system and help the body produce more metabolic enzymes. Pepsin, bromelain, etc. are animal based enzymes that help in digestion, as an anti-inflammatory agent. Trypsin helps in braking down arginine or lysine and is active at alkaline ph. The other enzymes that carry out chemical reactions are rennin that readies the milk for the action of pepsin and lipase by breaking it down to proteins and fats.( www.enzymestuff.com)
Enzymes work throughout the digestive system; however each enzyme will only work in specific areas under the correct conditions. Enzymes are composed of long chains of amino acids that have folded into a very specific three-dimensional shape which contains an active site. An active site is a region on the surface of an enzyme to which substrates will bind and which catalyses a chemical reaction involving the substrate. The active site of each enzyme has a very specific and intricate shape and it also has distinct chemical properties that match those of its substrate. Not only does the substrate molecule fit the shape of the active site but it is also chemically attracted to it. Enzymes are specific as each type of one catalyses one particular reaction and works on one particular substrate. The specific action of an enzyme with a single substrate can be explained using a Lock and Key analogy . In this analogy, the lock is the enzyme and the key is the substrate. Only the correctly sized key fits into the key hole) of the lock.
Smaller keys, larger keys, or incorrectly positioned teeth on keys (incorrectly shaped or sized substrate molecules) do not fit into the lock (enzyme). Only the correctly shaped key opens a particular lock. This is illustrated below.

The induced-fit theory assumes that the substrate plays a role in determining the final shape of the enzyme and that the enzyme is partially flexible. This says why certain compounds can bind to the enzyme but do not react because the enzyme have been distorted too much. Other molecules may be too small to induce the proper alignment and therefore cannot react. Only the proper substrate is capable of inducing the proper alignment of the active site.

Enzymes are pH sensitive therefore they only work in those areas suitable for them. A change in pH disrupts an enzyme 's shape and structure. When the pH changes an enzyme 's structure, the enzyme can 't do its job. Changes in pH break the delicate bonds that maintain an enzyme 's shape. An enzyme will unravel, or denature, and become useless in a different PH.

Enzyme activity will increase as temperature increases (often doubles with every 10˚C rise). At a higher temperature more collisions occur between the substrate and the enzymes due to faster movement of molecules. However, at high temperatures enzymes are denatured and stop working. High heat causes vibrations inside the enzymes which break bonds needed to maintain the structure of the enzyme. . (www.bing.com)
As pH levels increase or decrease from the optimum level for each specific enzyme, the activity level is reduced. Both acids and alkalis can denature enzymes. A pH of 7 is optimum for most enzymes. (www.bing.com) (www.bing.com)

Substrate concentration has an effect As the concentration of substrate increases, the rate of reaction also increases until the point saturation occurs. It means as you increase the concentration, rate keeps increasing and then one point comes when the maximum rate is achieved and there is no free enzyme to bind with substrate and all the active sites of enzyme are bound to the substrate. So after that point, increasing the concentration wont have any effect.
Enzyme concentration usually a very small amount of enzyme can consume a large amount of substrate. The rate of reaction depends directly on the amount of enzyme present at a specific time at unlimited substrate concentration. If two folds increase the amount of enzyme the reaction rate is doubled. By increasing the enzyme molecules an increase is the number of active sites takes place. At higher concentration of the enzyme the inhibitors will fall short. More active sites will convert the substrate molecules into products, in the given period of time. After a certain limiting concentration, the rate of reaction will no longer depend upon this increase. (faculty.clintoncc)

REFERENCES http://www.herbs2000.com/h_menu/enzymes.htm http://www.ehow.com/digestive-enzymes/ http://www.enzymestuff.com/basicswhichenzyme.htm www.bing.com
http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Laboratory/Enzymes/Enzymes.htm

References: http://www.herbs2000.com/h_menu/enzymes.htm http://www.ehow.com/digestive-enzymes/ http://www.enzymestuff.com/basicswhichenzyme.htm www.bing.com http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Laboratory/Enzymes/Enzymes.htm