Enzymes are biological catalysts for mainly proteins which speed up reactions without being chemically changed by reducing energy barriers these enzymes can be found in plants and animal cells. Enzymes are able to fold in to complex shapes this allows molecules which are smaller to fit within them. Enzymes join a substrate complex molecule without changing the structure which are temporary held within the active site. When the reaction has occurred the enzymes separates then connects to another molecule. Enzymes are essential for life serving important in the body for digestion and metabolism breaking down molecules to smaller molecules so they can be absorbed by the body (Campbell and Reece, 2005). There are many factors that effect the …show more content…
Maximal velocity (Vmax) is used to measure when the sub rate concentration has increased. Resulting in enough substrate molecules filling the active site Vmax is the rate of reaction under these conditions reflecting on how fast the enzymes are being catalysed (Karp, 2009). Km is the michaelis constant in moles in the solution which is measured as half the maximal velocity (Km=1/2 Vmax). This varies between the different enzymes substrates if a small Km is recorded this suggests that the substrates are bonded tightly to the enzyme. A larger recording shows that the binds are much weaker. Vmax and Km is important to represent the amount of enzyme added and the time required to become synthesised from the amount of subtract used (Alberts et al., 2013). The salivary glands secret high quantities of α- amylase which allows the enzymatic process of digestion of starch beginning in the oral cavity and can also be found in the pancreas (Witts 2005). α - amylase catalyses hydrolysis of starch reaction 1-4 glycosidic to yield maltose which is a reducing sugar from 3- 5 dinitrosalicylic acid. The Benedict’s test is used when reducing sugar are tested they continue to colour change from green to yellow, orange, brown and red depending on the quality of reducing sugar (Toole and Toole, …show more content…
As 1% (w/v) starch solution = 1g of starch in 100ml of water. 0.07% (w/v) = 4.375µmols 0.14% (w/v) = 8.75µmols 0.28% (w/v) = 17.5µmols . To working out Km: -1/-0.058 mg/ml = 17.24 µmols.min-1.mg-1 and to determine Vmax: 1/1.9mg/ml = 0.52 µmols.min-1.mg-1 from these results show Vmax in µmols of maltose produced per minute per mg of α-amylase (µmols.min-1. mg-1). The smaller valve of km suggest that the affinity of the enzymes is higher. The results from the graph showing the amount of maltose released by the action of α-amylase in each tube show that as the starch concentration increase the kinetic energy speeds up. The starch concentration of 0.28%(w/v) has shown that as the maximum time measured is met the maltose concentration 1.12mM showing that maximum activity occurred at this point. A study conducted by Enemchukwu et al., (2013) into α-amylase enzyme samples from one hundred healthy adult smokers and fifty non smokers. This experiment showed the effects of temperature, pH and substrate concentration. The results showed that the Km valve of 3.30 ×10–2 mg/ml and 3.37×10–2mg/ml results from smokers and non smokers. The results suggest maximum activity occurred at the optimum temperature (40°C). Enemchukwu et al., (2013) concluded with stating that smoking has no effect on the salivary α-amylase enzyme
For example, if a person had been able to consume lactose products for their life with no problems, but in an unfortunate event had to have a portion of his or her small intestine removed, there would be a change in the number of present lactase enzymes in the stomach. Because the lactase enzyme is stored in the small intestine, the person may now experience lactose intolerance due to the decrease in the presence of lactase. Knowing where the lactase enzyme is stored can aid physicians in understanding what will happen after a procedure or the introduction of a new medication. The experiment was conducted to determine the optimal ph of lactose required to produce the maximum amount of glucose. It was predicted that the optimal ph of lactose would be most efficient at lactose ph 6, and that the lower the ph, the amount of glucose produced would increase
The control for both curves was the beaker with 0% concentration of substrate, which produced no enzyme activity, as there were no substrate molecules for...
Purpose: The purpose of this lab is to explore the different factors which effect enzyme activity and the rates of reaction, such as particle size and temperature.
The independent variable for this experiment is the enzyme concentration, and the range chosen is from 1% to 5% with the measurements of 1, 2, 4, and 5%. The dependant variable to be measured is the absorbance of the absorbance of the solution within a colorimeter, Equipments: Iodine solution: used to test for present of starch - Amylase solution - 1% starch solution - 1 pipette - 3 syringes - 8 test tubes – Stop clock - Water bath at 37oc - Distilled water- colorimeter Method: = == ==
Affect of the Rate of Reaction of Amylase on Starch and How Its Affected by the Concentration of the Substrate
Background information:. Enzyme Enzymes are protein molecules that act as the biological catalysts. A Catalyst is a molecule which can speed up chemical reactions but remains unchanged at the end of the reaction. Enzymes catalyze most of the metabolic reactions that take place within a living organism. They speed up the metabolic reactions by lowering the amount of energy.
Proteins are one of the main building blocks of the body. They are required for the structure, function, and regulation of the body’s tissues and organs. Even smaller units create proteins; these are called amino acids. There are twenty different types of amino acids, and all twenty are configured in many different chains and sequences, producing differing protein structures and functions. An enzyme is a specialized protein that participates in chemical reactions where they serve as catalysts to speed up said reactions, or reduce the energy of activation, noted as Ea (Mader & Windelspecht).
According to the graph on amylase activity at various enzyme concentration (graph 1), the increase of enzyme dilution results in a slower decrease of amylose percentage. Looking at the graph, the amylose percentage decreases at a fast rate with the undiluted enzyme. However, the enzyme dilution with a concentration of 1:3 decreased at a slow rate over time. Additionally, the higher the enzyme dilution, the higher the amylose percentage. For example, in the graph it can be seen that the enzyme dilution with a 1:9 concentration increased over time. However, there is a drastic increase after four minutes, but this is most likely a result of the error that was encountered during the experiment. The undiluted enzyme and the enzyme dilution had a low amylose percentage because there was high enzyme activity. Also, there was an increase in amylose percentage with the enzyme dilution with a 1: 9 concentrations because there was low enzyme activity.
Investigating The Effect of Temperature on the Structure of an Enzyme Introduction: For my GCSE Biology assessment I will be investigating the enzyme amylase with the substrate starch. This reaction, which I am going to investigate, is called the protein test for starch. Aim: My intention for this observation is to examine how the enzyme catalyses are affected by changes in temperature. Safety Precautions: In this investigation I am going to make sure that everything is as safe as possible and prevent any accidents from occurring.
at a volume of 4cm3. The preliminary work also proved to me that my basic method worked without any setbacks that may affect my results. Variables:.. The variables involved in the rate of reaction between amylase and starch are. The volume of amylase The volume of starch
Enzymes have the ability to act on a small group of chemically similar substances. Enzymes are very specific, in the sense that each enzyme is limited to interact with only one set of reactants; the reactants are referred to as substrates. Substrates of an enzyme are the chemicals altered by enzyme-catalysed reactions. The extreme specific nature of enzymes are because of the complicated three-dimensional shape, which is due to the particular way the amino acid chain of proteins folds.
Enzymes are types of proteins that work as a substance to help speed up a chemical reaction (Madar & Windelspecht, 104). There are three factors that help enzyme activity increase in speed. The three factors that speed up the activity of enzymes are concentration, an increase in temperature, and a preferred pH environment. Whether or not the reaction continues to move forward is not up to the enzyme, instead the reaction is dependent on a reaction’s free energy. These enzymatic reactions have reactants referred to as substrates. Enzymes do much more than create substrates; enzymes actually work with the substrate in a reaction (Madar &Windelspecht, 106). For reactions in a cell it is important that a specific enzyme is present during the process. For example, lactase must be able to collaborate with lactose in order to break it down (Madar & Windelspecht, 105).
= == In relative terms enzymes are biological catalysts; control the rate of chemical reaction, different temperatures and pH’s affect their optimum rate of reaction in living organisms. In detail; enzymes are globular proteins, which catalyse chemical reactions in living organisms, they are produced by living cells – each cell has hundreds of enzymes. Cells can never run out of enzymes as they or used up in a reaction.
Changes in pH lead to the breaking of the ionic bonds that hold the tertiary structure of the enzyme in place. The enzyme begins to lose. its functional shape, particularly the shape of the active site, such. that the substrate will no longer fit into it, the enzyme is said to. be denatured.
In order to understand enzyme kinetics, it is important to understand Vmax and Michaelis-Menten constant. The rate of reaction catalyzed by an enzyme increases linearly with the substrate concentration up to a point but soon reaches the maximum value called Vmax beyond which there is no further increase in reaction rate. Michaelis and Menten define a constant, designated as Km which is useful