What Influences Enzyme Activity
Biology Lab
2010-09-25
Summary
In this lab we learned about what influences enzyme activity. We learned many terms and concepts in this lab. Enzymes decreases the amount of energy needed in a reaction. Catalyst speeds up reaction. A substrate is what the material with which catalyst reacts. A product is the modification of the substrate. This was a very informative and good lab.
Materials
1. 1 Reaction spot plate
2. 3 Small Cups
3. 3 Plastic pipettes
4. 1 Bottle starch indicator solution.
5. Prepared starch solution
6. Prepared diastase solution
7. Distilled water
8. Clock with second hand
9. Bottle of dilute hydrochloric
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2. Add two drops of starch solution in each of the two wells.
3. Add a drop of enzyme solution to only one of the wells. The other well without enzyme added to it will be your control.
4. After 3 minutes, test for the presence of sugar formation in both of the wells. Wait 10 seconds, then observe and record any color change in Table 4. The indicator changes color in varying degrees, from the initial pink to dark purple in the presence of increasing concentrations of glucose. A color change after 10 seconds is indicative of glucose production from the digestion of starch.
5. After testing for glucose, add one drop of the starch indicator solution to both wells to test for the presence of starch. Record your observations.
Results
Table Number 1- Reaction Times With Increasing Enzyme Concentration
|Number of Drops of Enzyme |Reaction Time (sec) |
|1 |360 |
|2 |60 |
|3 |40 |
The purpose of this lab was to test different substances using various procedures to see what biomolecules were present and ultimately find out what restaurant Anna Lyza had eaten at before she died. For the first control test, we used vegetable oil to test for lipids. So, if the solution does not contain lipids, it does not become translucent when placed onto a paper bag square and held up to a light. So, it is a negative result. However, in the presence of lipids, the solution will become translucent when placed onto a paper bag square and held up to a light. Therefore in this case, the result is positive. On the other hand, we used albumin egg to test for proteins in another control test. If the solution does not contain proteins, it will not experience any color change and so it is a negative result. When there are proteins existing in the solution, it will turn bluish/purplish and for this reason it is a positive result. Furthermore in the third control test, we used dextrose to test for simple carbohydrates such as glucose. If the solution does not contain simple carbohydrates, it will not undergo any color change and will remain a blue color. So, it is a negative result in this circumstance. If there are simple carbohydrates present in the solution, the solution will turn reddish and so the result is positive. For the last control test, we used starch solution to test
Enzymes are biological catalysts, which means it decreases activation energy in reactions. The lower activation energy in a reaction, the faster the reaction rate. Many enzymes alter their shape when they bind to the activation site. This is called induced fit, meaning for the enzyme to work to its full potential it has to change shape to binding substrate. The location of enzyme’s activation site is on the surface of the enzyme, where the binding of substrates take place. Enzyme activity can be influenced by a variety of environmental factors. If the concentration of enzyme is low, and there is a great deal of substrate, then increasing enzyme concentration results in more molecules available to convert substrates to products. Thus, increasing enzyme concentration can increase reaction rate. If substrate concentrations are low, and many of the existing enzymes are idle because of a lack of substrate, then adding enzyme will have no effect on reaction rate. Enzyme concentration affects the enzyme activity, because the more enzyme concentration the faster the reaction rate, until it hits it’s limiting factor. When substrate concentration is increased, it also increases rate of reaction. Temperature plays an important
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
During the eighteenth century a group of French writers and critics known as the Philosophes favored change and reform. They believed in the power of the human mind, which was an idea that was inspired by the Scientific Revolution. The philosophes had faith in the power of rational criticism to challenge the tradition of the past. They also sought to apply the rules of reason and common sense to nearly all major institutions and social practices. The philosophes proposed a new kind of organized religion, a social religion which encouraged harmony and tolerance while strengthening the bonds of moral obligations within society. One of the major French philosophes during the eighteenth century was Voltaire.
b) Benedict test the solution color will change from blue to pink/orange red, indicating simple sugars are present. Lugols test the solution color will change from yellowish brown to dark purple, indicating starch and polysaccharides are present. Sudan iV test the lipid content will turn into red, indicating lipids are
11. It is then repeated for the solution of unknown concentration (A, B or C).
4.Measure 35mL of warm water and add them into each of the 4 test tubes at about roughly the same time. It is essential that the water is warm. Do not seal the test tube.
Enzymes are a key aspect in our everyday life and are a key to sustaining life. They are biological catalysts that help speed up the rate of reactions. They do this by lowering the activation energy of chemical reactions (Biology Department, 2011).
Sugar content in organic products versus natural products tested with thin layer chromatography Carbohydrates are one of the most important components for food sources. Carbon based molecules are also called organic compounds. Large organic molecules have elaborate shapes. The chain of carbon atoms is called a carbon skeleton. Other monosaccharides carbon skeletons may have 3 to 7 carbons.
Then 50 ml beaker with the glucose and starch mixture was also tested for glucose with a glucose strip. The dialysis tube was then clipped on one end and opened on the other end. The 15 ml of glucose and starch mixture was then poured into the dialysis tube with a pipette. The dialysis tube was then twisted and clipped on the unclipped end of the tube. The mass of the tube was then measured by a quadruple beam balance. The tube was then rinsed in the sink and blotted dry by a paper towel to clean the tube in case some of the glucose accidentally spilled out of the tube. The tube was then placed into the 250 ml beaker and left there to sit for 15 minutes. After 15 minutes, the 250 ml beaker was then tested for glucose with a glucose test strip and so was the contents inside of the tube. All observations and results were recorded in the chart below the procedure. Such observations listed were things like color change in the solutions, mass changes in the dialysis tubing, and what the glucose strips would indicate about the solution
Organisms cannot depend solely on spontaneous reactions for the production of materials because they occur slowly and are not responsive to the organism's needs (Martineau, Dean, et al, Laboratory Manual, 43). In order to speed up the reaction process, cells use enzymes as biological catalysts. Enzymes are able to speed up the reaction through lowering activation energy. Additionally, enzymes facilitate reactions without being consumed (manual,43). Each enzyme acts on a specific molecule or set of molecules referred to as the enzyme's substrate and the results of this reaction are called products (manual 43). As a result, enzymes promote a reaction so that substrates are converted into products on a faster pace (manual 43). Most enzymes are proteins whose structure is determined by its sequence of its amino acids. Enzymes are designed to function the best under physiological conditions of PH and temperature. Any change of these variables that change the conformation of the enzyme will destroy or enhance enzyme activity(manual, 43).
Record observations: what color did the solution turn? Orange or blue/ black? This will tell whether the amylase is able to denature the starch solution Orange=Negative Blue/black= Positive
After the 30 minutes, the color was observed and recorded on the data sheet. The dialysis tubing was removed from the beaker and a small slice was made, we then used a glucose indicator strip to test for the presence of glucose, along with the solution in the beaker. The results were then recorded in table 1on the data sheet.
Collect to 2 large beakers both large beakers are to be filled with hot water (labtutor). Then obtain seven conical tubes these will be used to collect the levels of gas, you will also need test tube a stopper and a plastic tube (labtutor). You want to fill the conical tube to at least 50 ml of water (Cressy). Take the four conical tubes filled with water and place two in each beaker, to do this you must invert the tube and cover the release hole as to not lose any water (Cressy). Then place the beakers with the tubes in the bath so they can be at the same temperature as the bath (Cressy). Next mark all of your test tubes in number order to be sure which tube contains what concentrations and pH (Cressy). Having mixed a solution to the specifications of 2.5 ml of glucose in all tubes, 3 ml of yeast in 2 tubes of pH 5, 2 tubes of pH 9, and the single pH 7 tube, the remaining two tubes will contain no yeast as they will be negative controls. Next add 2 ml of pH buffer 3 tubes will receive pH of 5, three will receive a pH of 9 and a single tube of pH 7. Finally add pure water to make sure all test tubes have 10 ml of solution. When making the solutions
The tubes are removed using a clamp and the concentration of maltose is compared using the following scale: red (+++), orange-yellow (++), green (+), blue (-).