Amylase Investigation

Have a little read: ... Amylase Investigation Aim Industries today rely on enzymes because they can make processes more profitable. Enzymes are biodegradable proteins that make production processes more efficient and cost-effective, resulting in higher quality products. Enzymes are the key to a sustainable future as they help protect the environment by reducing waste and the need for harsh chemicals. Our bodies also produce enzymes for example fighting diseases, growth and digestion. Therefore, in order to understand what to do when reactions in our bodies are not working very well or to make industries as efficient as possible, we need to know about the conditions enzymes work best in. This investigation deals with looking at which temperature the enzyme Amylase digests starch at the fastest. It investigates the effect of temperature on the breakdown of starch by amylase, and finding the optimum temperature for the reaction. Background Information Enzymes Enzymes, are any one of many specialized organic substances, composed of polymers of amino acids, that act as catalysts to regulate the speed of the many chemical reactions involved in the metabolism of living organisms. Enzymes are biological catalysts. Catalysis is defined as the acceleration of a chemical reaction by some substance which itself undergoes no permanent chemical change. For example, platinum is used to catalyse the reaction that breaks down nitrogen oxides in car exhaust, yet platinum has many other uses. Unlike ordinary catalysts, enzymes are specific to one chemical reaction. An ordinary catalyst may be used for several different chemical reactions, but an enzyme only works for one specific reaction. The catalysts of biochemical reactions are enzymes and are responsible for bringing about almost all of the chemical reactions in living organisms. Without enzymes, these reactions take place at a rate far too slow for the pace of metabolism. Plants, animals, bacteria, or fungi, if they are alive, use enzymes to control all living chemical reactions. Plants turn the energy of sunlight directly into food by tying sunlight energy into chemical bonds in the form of sugar. Enzymes are responsible here too; they control the absorption of radiant energy. Yeast use enzymes to levin bread and ferment sugar into alcohol. Bacteria use enzymes to break down cellulose fibre in the stomachs of cows and the stomachs of termites. Reproduction, growth, metabolism, synthesis, are all enzymes regulated reactions in living things. Enzymes are made from amino acids, and they are proteins. Because they are made up of proteins, they are sensitive to heat, pH and heavy metal ions. When an enzyme is formed, it is made by stringing together between 100 and 1,000 amino acids in a very specific and unique order. The chain of amino acids then folds into a unique shape. That shape allows the enzyme to carry out specific chemical reactions. An enzyme acts as a very efficient catalyst for a specific chemical reaction. Examples of enzyme-aided reactions include all digestion, growth and building of cells, any breakdown of substances such as vitamins, and nutrients, and all reactions involving transformation of energy. Enzymes also control reactions. The rate and location or site of a reaction is also controlled by enzyme action. A good example of the involvement of enzyme action is in the building of living material within the cell. The human body probably contains about 10,000 different enzymes. At body temperature, very few biochemical reactions proceed at a significant rate without the presence of an enzyme. Lack of specific enzymes is the cause of many disorders. Disorders such as albinism, diabetes, and cystic fibrous are traceable to either a lack of a specific enzyme or an imbalance of one. Human saliva contains an enzyme called amylase. This enzyme helps to turn starch into a sugar called maltose. When you swallow a mouthful of food, the amylase stops working because it is too acidic in the stomach (pH 2). Amylase works best in neutral or slightly alkaline conditions, i.e. at about pH 7. When your food gets into the small intestine, the pancreas makes more amylase and this turns the remaining starch into maltose. Another enzyme (maltase) turns all this maltose into glucose. Glucose is then absorbed into the blood. Enzymes in the human alimentary canal and what they digest are shown in Table 1: Table 1 The name enzyme was suggested in 1867 by the German physiologist Wilhelm Kühne (1837-1900); it is derived from the Greek phrase en zymç, meaning "in leaven". Identified enzymes now number more than 700. Enzymes are classified into several broad categories, such as hydrolytic, oxidizing, and reducing, depending on the type of reaction they control. Hydrolytic enzymes accelerate reactions in which a substance is broken down into simpler compounds through reaction with water molecules. Oxidizing enzymes, known as oxidases, accelerate oxidation reactions; reducing enzymes speed up reduction reactions, in which oxygen is removed. Many other enzymes catalyse other types of reactions. Enzymes work by bonding molecules so that they are held in a particular geometric configuration that allows the reaction to occur. Enzymes are very specific; few molecules closely fit the binding site. Each enzyme catalyses a specific type of chemical reaction between a few closely related compounds, which are called substrates. Individual enzymes are named by adding ase to the name of the substrate with which they react. In older names the suffix is added to the name of the substrate, as in amylase, an enzyme that breaks down the polysaccharide amylose. In newer names, the suffix is added to the type of reaction, as in lactase dehydrogenase, an enzyme that converts lactase to pyruvate by transferring a hydrogen atom to nicotinamide-adenine dinucleotide (NAD). The enzyme that controls urea decomposition is called urease; those that control protein hydrolyses are known as proteinases. Some enzymes, such as the proteinases trypsin and pepsin, retain the names used before this nomenclature was adopted. The active site on the enzyme attaches to a substrate molecule (such as a disaccharide) forming an enzyme-substrate complex. While attached to the substrate, the enzyme causes a weakening of certain chemical bonds in the substrate molecule, resulting in a breakdown (hydrolysis) of the substrate into two smaller product molecules (such as two monosaccharides). The enzyme is unaltered during the reaction and is free to catalyse the breakdown of another substrate molecule. The enzyme and the substrate fail to bind if their shapes do not match exactly. This ensures that the enzyme does not participate in the wrong reaction. When the products have been released, the enzyme is ready to bind with a new substrate. A theory to explain the catalytic action of enzymes was proposed by the Swedish chemist Savante Arrhenius in 1888. He proposed that the substrate and enzyme formed some intermediate substance, which is known as the enzyme substrate complex. The reaction can be represented as: S + E ES Or it can also be represented as: S + E ES P + E Properties of Enzymes As the Swedish chemist Jöns Jakob Berzelius suggested in 1823, enzymes are typical catalysts: they are capable of increasing the rate of reaction without being consumed in the process. All known enzymes are proteins. They are high molecular weight compounds made up principally of chains of amino acids linked together by peptide bonds: Enzymes can be denatured and precipitated with salts, solvents and other reagents. They have molecular weights ranging from 10,000 to 2,000,000. Many enzymes require the presence of other compounds -cofactors- before their catalyst activity can be exerted. This entire active complex is refereed to as the holoenzyme, i.e., apoenzyme (protein portion) plus the cofactor (coenzyme, prosthetic group or metal-ion-activator) is called the holoenzyme. One of the properties of enzymes that make them so important as diagnostic and research tools is the specificity they exhibit relative to the reactions they catalyse. A few enzymes exhibit absolute specificity, that is, they will catalyse only one particular reaction. Other enzymes will be specific for a particular type of chemical bond or functional group. In general, there are four distinct types of specificity: Absolute specificity - the enzyme will catalyse only one reaction. Group specificity - the enzyme will act only on molecules that have specific functional groups, such as amino, phosphate and methyl groups. Linkage specificity - the enzyme will act on a particular type of chemical bond regardless of the rest of the molecular structure. Stereo-chemical specificity - the enzyme will act on a particular steric or optical isomer. Some enzymes, such as pepsin and trypsin, which bring about the digestion of meat, control many different reactions, whereas others, such as urease, are extremely specific and may accelerate only one reaction. Still others release energy to make the heart beat and the lungs expand and contract. Many facilitate the conversion of sugar and foods into the various substances the body requires for tissue-building, the replacement of blood cells, and the release of chemical energy to move muscles. Pepsin, trypsin, and some other enzymes possess, in addition, the peculiar property known as autocatalysis, which permits them to cause their own formation from an inert precursor called zymogene. As a consequence, these enzymes may be reproduced in a test tube. Enzymes can be classified by the kind of chemical reaction catalysed: 1. Addition or removal of water Hydrolases - these include esterases, carbohydrases, nucleases, deaminases, amidases, and proteases. Hydrases such as fumarase, enolase, aconitase and carbonic anhydrase. 2. Transfer of electrons Oxidases. Dehydrogenases. 3. Transfer of a radical Transglycosidases - of a monosaccharides. Transphosphorylases and phosphomutases - of a phosphate group. Transaminases - of amino group. Transmethylases - of a methyl group. Transacetylases - of an acetyl group. 4. Splitting or forming a C-C bond Desmolases. 5. Changing geometry or structure of a molecule Isomerases. 6. Joining two molecules through hydrolysis of pyrophosphate bond in ATP or other triphosphate Ligases. Enzymes are extraordinarily efficient. Minute quantities of an enzyme can accomplish at low temperatures what would require violent reagents and high temperatures by ordinary chemical means. About 30 g (1 oz) of pure crystalline pepsin, for example, would be capable of digesting nearly 2 tonnes of egg white in a few hours. The kinetics of enzyme reactions differ somewhat from those of simple inorganic reactions. Each enzyme is selectively specific for the substance in which it causes a reaction and is most effective at a temperature peculiar to it. Although an increase in temperature may accelerate a reaction, enzymes are unstable when heated. The catalytic activity of an enzyme is determined primarily by the enzyme's amino-acid