Background
An enzyme is a biological catalyst which speeds up biochemical reactions, such as digestion and respiration, but they remained unchanged at the end of the process (Walpole, Merson-Davies, and Dann 53).
Problem Question
What is the effect of the substrate concentration on enzyme activity?
Hypothesis
As the concentration of the substrate increases, the rate of reaction also increases until it reaches its maximum point where all enzyme molecules are already active due to the solution becomes saturated with the hydrogen peroxide. Therefore, when the rate of reaction is finally at its maximum point, adding more substrate will not make any difference to the rate of reaction.
The rate of reaction increases when the substrate is added it caused the oxygen to be produced quickly. When the substrate molecules go beyond the number of active sites that is available, the rate of reaction will stop increasing. This is because the maximum point of reactions have been reached and are being done at once so if there is any additional substrate molecules in the process, they need to wait until the active sites are available for them.
Variables
Factors Variables How it is conducted
Independent Concentration of H2O2. Set up using syringe with the following concentration of H2O2;
1%
5%
10%
15%
20%
Dependent Rate of reaction - volume of O2 released by each concentration of H2O2. Make sure to be at the right eye level with the bottom of the meniscus to read the long graduated tube.
Controlled Variables WHY it must be controlled HOW it was controlled
1 Volume of the yeast suspension The experiment was done to investigate is the effect of the substrate concentration on enzyme activity. Always take 5mL of the yeas...
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...he one that was measured. Use a better quality burette than can help the experimenter to see the reading of the initial and final oxygen released better or the experimenter may ask for other’s assistance in the reading of the measurement.
Uncontrolled variable Although the temperature was controlled, trial 1 and trial 2 were done on a different day as trial 3, trial 4 and trial 5. Do all trials in the experiment on the same in order to make everything as similar as possible prior to beginning testing.
Human/experimenter error There might be a slight delay when the experimenter was injecting the syringe into the boiling tube while the experimenter also started and stopped the stopwatch. In order to make it more accurate, perhaps ask for another person’s assistance for doing one of the tasks; timing for 30 seconds or injecting the syringe into the boiling tube.
9. Get your stopwatch ready and drop the Alka-Seltzer tablet at the same time you started the timer. 10. When it finishes dissolving (you can see through the water and there is no more fizzing.) stop the timer and record the results. 11.
For both experiments, data were collected for thirty seconds.
The procedure of the lab on day one was to get a ring stand and clamp, then put the substance in the test tube. Then put the test tube in the clamp and then get a Bunsen burner. After that put the Bunsen burner underneath the test tube to heat it. The procedure of the lab for day two was almost exactly the same, except the substances that were used were different. The
Enzymes are biomolecules that catalyze or assist chemical reactions. ("Enzyme Information - Disabled World", n.d.,) Without enzymes it would be impossible for an organism to carry out chemical reactions. Enzymes are proteins that carry a chemical reaction for a specific substance or nutrient. For example, the digestive enzymes help food to be broken down so it can be absorbed. Enzymes can either initiate the reaction or speed it up. Substrates are the chemicals that are transformed by enzymes. (Gunsch & Foster, 2014) Reactants are the chemicals in the absence of enzymes. Metabolic pathways that occur in a cell are determined by a set of enzymes which are selective for their substrates and catalyze only a few reactions among the many possibilities.
Possible sources of error in this experiment include the inaccuracy of measurements, as correct measurements are vital for the experiment.
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.
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.
* Size of potatoes * Diameter of each potato tube * Time in sugar solution We need to make sure in both experiments the fair test lists are used and the procedures are carried out. This needs to be done otherwise my results will not be accurate and will look odd. Method: Firstly we got out all our equipment.
I shall be measuring how much gas is given off. This will be done by measuring the amount of froth on the surface of the liquid. The oxygen released is collected in the form of these bubbles. The equation for the reaction is: (catalase) [IMAGE] H2O2 2H2O + O2 (hydrogen peroxide) (2 part water) (oxygen) I will change the concentration of H2O2 and O2 (making sure the volume stay the same, when one part of a H2O2 particle is taken, an O2 particle is added. Prediction
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).
After the water, has been boiling for 10 minutes, and the temperature inside the test tube has been stable for 5 minutes, record the temperature and remove the thermometer.
In a 250ml beaker place 100mls of water, measure the temperature of the water and record this initial temperature onto a table. Set the timer and add one teaspoon of Ammonium Nitrate to the water, stir this continuously until the Ammonium Nitrate has dissolved. After 1 minute measure the temperature and record it, do this for a further 2 minutes (3 minutes in total). Repeat this process for a total of 10 teaspoons.
Also changes in pH affect the charges on the amino acids. within the active site such that the enzyme will not be able to form. an enzyme substrate complex. The pH at which an enzyme catalyses a reaction at the maximum rate is called the optimum pH. This can vary considerably from pH 2 for pepsin. to pH 9 for pancreatic lipase.
The time taken for this to happen is the measure of the rate of reaction. We must do this several times, and change the concentration of sodium thiosulphate. The rate of reaction is a measure of the change, which happens during a reaction in a single unit of time. The things that affect the rate of reaction are as follows. Surface area of the reactants Concentration of the reactants
There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.