Enzyme Lab Report

In this lab or experiment, the aim was to determine the following factors of enzymes: (1) the effects of enzymes concentration the catalytic rate or the rate of the reaction, (2) the effects of pH on a particular enzyme, an enzyme known and referred throughout this experiment as ALP (alkaline phosphate enzyme) and lastly (3) the effects of various temperatures on the reaction or catalytic rate. Throughout the experiment 8 separate cuvettes and tubes are mixed with various solutions (labeled as tables 1,3 & 4 in the apparatus/materials sections of the lab) and tested for the effects of the factors mentioned above (concentration, pH and temperature). The tubes labeled 1-4 are tested for pH with pH paper and by spectrophotometer, cuvettes 1a-4a was tested for concentration and cuvettes labeled 1b-4b was tested for temperature in four different atmospheric conditions (4ºC, 23ºC, 32ºC and 60ºC) to see how the enzyme solution was affected by the various conditions. After carrying out the procedures the results showed that the experiment followed the theory for the most part, which is that all the factors work best at its optimum level. So, the optimum pH that the enzymes reacted at was a pH of 7 (neutral), the optimum temperature that the reactions occurs with the enzymes is a temperature of 4ºC or

Enzyme catalysis is dependant upon factors such as concentration of enzyme and substrate, temperature and pH. These factors determine the rate of reaction, and an increase in temperature or pH above the optimum will

Enzymes are biological catalysts, which speed up the rate of reaction without being used up during the reaction, which take place in living organisms. They do this by lowering the activation energy. The activation energy is the energy needed to start the reaction.

Enzymes are catalysts that function to speed up reactions; for example, the enzyme sucrose speeds up the hydrolysis of sucrose, which breaks down into glucose and fructose. They speed up reactions but are not consumed by the reaction that is taking place. The most important of the enzyme is the shape as it determines which type of reaction the enzyme speeds up. Enzymes work by passing/lowering and energy barrier and in doing so; they need to bind to substrates via the active. Once they do, the reaction speeds up so much more quickly than it would without the enzyme. Coenzymes and cofactors aid the enzyme when it comes to binding with the substrate. They change the shape of the active site so the substrate can bind properly and perform its function.

2. We measured 1 mL of turnip peroxidase (the enzyme) and 3 mL of neutral buffer (pH corresponding to the test tube number i.e. pH 5 in test tube 5) with a syringe and disposed it into tubes 3, 5, 6, 7, 8, and 10

Hypothesis: If the temperature increases, then rate of the chemical reaction will increase as well, and if the temperature decreases, then the rate of reaction will also decrease.

1. An enzyme is a macromolecule that acts as a catalyst and also speeds up reactions.

Enzyme = 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. (Microsoft® Encarta® Encyclopedia '99.)

We then tested the last set of test tubes containing milk and lactase, we did this to find which ones would present the most glucose concentration results, when placed in different temperatures, 4°C, boiling and room temperature. What we wanted to know was how far temperature could affect lactase to perform its enzymatic activity. We hypothesized that if the lactase is placed in a high or low temperature outside its active range, the temperatures would have a negative impact on the functions of the enzyme. If the temperature has an affect on lactose then we would see some temperatures in which lactase will be function able. We came to a conclusion that enzymes work at a temperature that is closest to body temperature (25°C); boiling water (100°C) denatures the enzyme, while the enzyme is not able to function properly if

The overall purpose of the lab was to study an enzyme found in the liver called catalase and how its rate of reaction was dependent on the specific conditions surrounding it. The research question provided for this lab was: “How do pH, temperature and surface area affect the action of catalase?”

First Day: Water Extraction of the Enzyme In a 400-mL beaker, wheat germ (50 g) and cold distilled water (200 mL) were added. The beaker was placed in an ice bath and the wheat germ solution was stirred for 30 minutes. The wheat germ solution was transferred to a centrifuge bottle and it was centrifuged for 10 minutes. After centrifuging, the wheat germ solution was measured in a graduated cylinder and transferred into a clean centrifuge bottle, discarding the pellet (PI). The supernatant I (SI), containing the enzyme, was placed in the freezer.

In the following experiments we will measure precise amounts of potato extract as well as Phenylthiourea, combined with or without deionized water and in some instances change the temperature and observe and record the reaction. We will also investigate the different levels of prepared pH on varying samples of the potato extract and the Phenylthiourea and record the results. We will answer question such as what is the best temperature for optimum temperature reaction as well as the best pH level for the same reaction.

The results from this experiment show the effects that concentration, pH and temperature have on enzyme activity. In part A, three different concentrations of enzyme solutions were tested. The undiluted enzyme had the fastest enzyme activity, the 1:9 dilution had the slowest enzyme activity and the 1:3 dilution fell in between the undiluted one and the 1:9 dilution. This result showed that the undiluted enzyme converts the amylose at a faster rate. Increasing enzyme concentration will increase the rate of reaction because more active sites are available to bind to substrate and more enzymes will be colliding with substrate molecules (Berkson 1937).

The purpose of this lab report is to investigate the effect of substrate concentration on enzyme activity as tested with the enzyme catalase and the substrate hydrogen peroxide at several concentrations to produce oxygen. It was assumed that an increase in hydrogen peroxide concentration would decrease the amount of time the paper circle with the enzyme catalase present on it, sowing an increase in enzyme activity. Therefore it can be hypothesised that there would be an effect on catalase activity from the increase in hydrogen peroxide concentration measured in time for the paper circle to ride to the top of the solution.

Enzymes are catalytic proteins that act to speed up chemical reactions that occur in our bodies and in the bodies of many other organisms by reducing the amount of activation energy required in order for a reaction to occur. Without enzymes, the chemical reactions that take place in all organisms would take place too slowly to keep the organism alive. Since all enzymes are proteins, and protein’s functions are dependent on their structure, enzymes require certain conditions to maintain their perfect structure. The disorder of structure and function of an enzyme is known as denaturation. Certain factors such as temperature, pH, enzyme concentration, and substrate concentration have certain effects on enzyme activity. To investigate the effects of these different conditions, an experimental investigation was set up to test the four different variables and their effect on the enzyme catecholase as it catalyzes catechol, the solute. Results can be seen on Figures A – D.