How to write a formal lab report correctly. This is based off a lab done in AP biology and all examples are taken from student lab write-ups.

Transcription

1 How to write a formal lab report correctly. This is based off a lab done in AP biology and all examples are taken from student lab write-ups. Title: Potato Catalase Enzyme Lab (1 point). * Objective, variables, and hypothesis ALL go together. Therefore determine the variables from the objective, and then write your hypothesis from the variables. * This information should also match how you word and answer questions in the conclusion. Objective: To determine which environmental factors: hot, cold, acidic, or basic reduces enzyme activity due to denaturation (1 point). Always use the lab directions objective unless you are doing in all inquiry lab. Good Example: To determine which factor: hot, cold, acidic, or basic environment reduces enzyme activity due to denaturation Bad Example: A- To determine what environment will cause the enzyme catalase to denature. B- To demonstrate the process of denaturation and observe different effects of an acid, base and hot and cold water. C- To observe the effects of different ph levels & temperature changes on enzyme reactions Variables: Independent (1 point for being correct) What specifically you are testing. Independent: environmental factors: hot, cold, acidic, or basic Dependent (1 point for being correct) What specific answer or result you are trying to obtain. Dependent: reduces enzyme activity *Incorrect variables lead to incorrect hypotheses. Bad Example: A-Independent- ph levels/temperature Dependent- Enzyme Amount B- Dependent: *Potato *water Independent: *Hydrogen peroxide *Vinegar *Baking Soda C- Independent: Acidic Factor Dependent: Catalysts Hypothesis: (2 points- for correct format of If...Then statement and for having the IF followed by the independent variable(s) and the THEN followed by the dependent variable. If an enzyme is tested in a hot, cold, acidic, and basic environment, then the acidic environment will reduce enzyme activity the most. Good Example: If enzymes are exposed to basic, acidic, hot, and cold environments, then the cold environment will cause the largest reduction in enzyme activity due to denaturation. Bad Example: A- If there is an increase in temperature then the intensity of the enzyme reaction will increase. If there is an acid the intensity of the enzyme reaction will increase rather than a base. B- If the environment of an enzyme changes based on great temperature and ph level then there will be less enzyme activity due to greater denaturation. C- If the environment is an acidic factor, then the catalysts reduces their speed of selective chemical reactions.

2 * This section is for Honors and Scholars: Materials list (2.5 points): May be in Bullet Points list or Numbered list. Good Example: * Hydrogen peroxide * 3 graduated cylinders HP, vinegar, base *Cup * Knife Good Example: 1. Vinegar 4. Test tubes 7. Hot water bath 2. Baking soda 5. Pipettes 8. Plate 3. Potatoes 6. Ice 9. Goggles Bad Example: grad. cylinder glass, grad. cylinder plastic, vinegar, hydrogen peroxide, 5 test tubes, goggles, plate, etc Procedure list (2.5 points): Must always be numbered in sequential steps and written so that it can be repeated by someone else. Good Example: Procedure: 1. Label the test tubes A, B, C,TH, and TC. A-acid, B- base, C- control, TH- temperature hot, TC- temperature cold. 2. Cut up and mash 5 grams of potatoes for each test tube, add potatoes to each test tube and 5 ml of water. Mix up contents. 3. Get 25 ml of hydrogen peroxide in a beaker and take it to your desk. 4. Add 5 ml of hydrogen peroxide to test tube C. Mark the start line of the potatoes and hydrogen peroxide solution Quickly with dry erase marker. DON'T SHAKE UP TEST TUBES AGAIN Measure the start and stop line distance and record data. Bad Example: 1. Label test tubes A B C TH TC 2. Cut up potatoes and add to tubes 3. Add 5 ml of water to tubes 4. Add 5mL of HP to tubes Measure Observations: A-(2 points) Written summary of what you did if you specifically manipulated something i.e. blowing soap bubbles. What you saw happening with Descriptive Details. These are the observations you are making as the lab is happening. No past tense conclusion type summary and no recap of procedure should be included here. Good Example: When hydrogen peroxide was added to test tube C the contents started bubbling immediately creating white frothy foam. The foam continued to increase in length up the test tube and even spilled out over the top of the test tube making it hard to measure an exact length of foam. Test tube A produced white foam but it was barely enough to measure. Test tube B produced foam and it rose to the top quickly also spilling out.

3 Bad examples: A-To begin the lab students labeled 5 test tubes with the letters A B C TH and TC. They then mashed up potatoes and put 5g of mashed potatoes in each tube and mixed with 5 ml of water and mixed each with 5mL of hydrogen peroxide. B- When hydrogen peroxide was added to each mixture different results had occurred. For the control the hydrogen peroxide immediately started to bubble a lot and slowed down after a minute. The acidic solution did nothing at all just like the hot temperature solution. C- During the lab foam was seen in test tubes to show enzyme activity. If there were many bubbles or long foam then there was high enzyme activity and if there were no bubbles/foam then there was no enzyme activity. B- (4 points) Numerical data- any and all measurements must be done using the metric system. No charts or tables should be here unless stated or given in the lab directions. Good Example: Test Tube A (acid): 1cm of foam length Test Tube B (base): 7cm of foam length Test Tube C (control): 11cm of foam length This is okay but written narration is not needed. The control test tube began at 2.5cm and increased to 12cm. The TC test tube started at 3.5cm and increased to 12.5cm. Bad Example: A- The control test tube s bubbles measured out to be 2.8 inches. The acidic environment only produced.2 inches of bubbles. This means that that hypothesis is correct; the acidic environment caused the largest decrease in enzyme activity. B- The control increased outside of the grad. cylinder There was a huge increase in the TC There was a 9 cm increase and it also stated to go out of the grad. cylinder Calculations :( 10 points total: 4 for graph or chart and 6 for correct labels, neatness, and color). A table, chart, and or graph should be in this section. THIS HAS TO BE BASED ON WRITTEN AND NUMERIC DATA THAT IS IN YOUR OBSERVATION SECTION. You could do a graph but for this lab a chart or table would be a better choice because written observation data was important as well as measured data. Good Example: A is better but B is acceptable and would not lose points. Test tube start to stop in cm obsv A. B.

4 Calculations continued Bad Example: A. B If graphs were expected here is a Good example and a Bad Example: Conclusion: The rubric states to answer each question separately. That means your answers should NOT be in paragraph form. It is okay to have a paragraph to answer one question but all 7 questions should NOT be in one paragraph. *Remember that you may not use pronouns even if the questions ask you to answer. And each question should be answered in a complete sentence. DO NOT write the question then answer in bullet point/note fashion. A complete sentence uses the question in the answer. a. (2 points) for 1-3 sentences regarding if your hypothesis was negated (incorrect) or supported (correct). Your answer should state the answer of your hypothesis and then state if it s supported or negated and answer the WHY using data from the lab. Good Example: The hypothesis stated that an acidic environment would decrease the enzyme activity the most due to denaturation. This hypothesis was supported because the enzyme

5 catalase experienced the greatest decrease in activity in the acidic environment, only a.2 cm foam length was measured as compared to the control with a 2.8 cm foam length. Bad Example: The hypothesis was supported because there was a greater amount of enzyme activity due to denaturation. b. (3 points) for 3-6 sentences giving a BRIEF summary of the observation section. It should include written and numeric data summary. Good Example: The reduction of enzyme activity varied between the different environmental factors tested. The acidic and hot environment had the least enzyme activity.2cm and.3cm foam length; there was barely enough bubble type foam to measure. However the cold test did not stop the enzyme activity at all and the foam length was 3.5cm which is actually a greater length than the control at 2.8cm. Bad Example: This is because in a cold environment there is enzyme activity while in hot environment enzyme activity is reduced. Along with the hot environment the acidic environment also reduced enzyme activity. In both hot and acidic there was no reaction. c. (0-5 points) these are additional lab questions to answer apart from the lab rubric conclusion questions A, B and D. These questions will be on the lab directions sheet or posted by the teacher. d. Making the connection. YOU NEED TO ANSWER THESE QUESTIONS USING PLENTY OF DESCRIPTION, DETAIL, AND EXPLAINATION. Questions 2 and 3 SHOULD BE MORE THAN ONE SENTENCE. If you are only writing one sentence you will lose points. Questions 1 and 4 can be one sentence without losing points. d. 1. (2 points) Purpose of the lab is to teach, show, and or have you participate in the objective. Good Example: The purpose of this lab was to give a visual and measurable model of enzyme activity being reduced due to environmental factors that caused denaturation. Bad Example: restating the objective word for word and not adding the CONNECTION pieces of seeing it and being able to measure it. d. 2. (3 points)what CONNECTIONS does this lab make to the topic you are learning? Good Example: This lab relates to topics in class such as biological macromolecules which include proteins and most enzymes are protein based. Proteins also have four structures they can stay in primary or they can change by going into each level to reach the fourth structure. When denaturation occurs in the protein, in this case an enzyme, its bonds are broken and it unfolds or unwraps into the structure formation below it. This causes the enzyme to become inactive. Another topic being learned is ph and ph values were manipulated in the testing of the enzyme catalase. An acidic environment with a ph below 7 was tested and a basic environment with a ph above 7 was tested. These topics have all been covered in class through reading, lecture, and activities/labs. Bad Example: The lab showed how a visual example of how certain environments can affect the reaction of enzymes due to denaturation. d. 3. What is more clear about the topic(s) you are learning now that you have completed this lab? Good Example: By completing this lab, it is clearer on how enzymes work, creating foamy bubbles when working properly, and how denaturation has a big part in effecting enzyme activity. This lab also showed how certain factors of the environment i.e., heat and acid can

6 reduce the enzyme activity by causing denaturation, no bubbles and foam, while cold and basic environments have little to no effect, therefore created bubbles and foam. Bad Example: A- It is more clear to me what environmental factors effect enzymes and how that process takes place. B- Enzymes and their effect on different substances were observed, and it is easier to understand the process of catalysis now after having done this lab. d. 4. What questions do you still have regarding the topics being learned or the lab? If you do not have questions then state that you do not have any further questions. If you do have questions and MOST OF YOU SHOULD HAVE QUESTIONS, be sure to not to ask questions you answered in your lab write-up. Your questions can be about the topic itself or the lab itself or both. Good Example: What would the results be if different salt solutions were added and tested on the enzyme? It stated in the textbook that salt can have an effect on enzyme activity too. Bad Example: What would happen if there was a different environment? Format: a. correct order of sections (2 points). You need to follow the sections in order in the lab rubric. b. Grammar, spelling, and complete sentences (4 points). READ your lab back to yourself out loud so that you find grammar mistakes such as wording and missing word issues. Example: The lab made connections to ph scale, catalysts, acid-base reactions, enzyme activity, and denaturation all lectured in class. The cold solution worked well but did not product as much foam as the control. Grammar and spell check won t pick up on correctly spelled words such as product instead of produce. b. continued- Complete sentences. They cannot start with It, They, or Because and cannot start with yes or no if you don t include what the yes or no is answering. Good Example: Complete sentences cannot start with It, They, or Because. Good Example: Yes an enzyme reaction occurred because 5cm of foam was produced. Bad Example: Yes, there was 5cm of foam produced. c. Written in third person. NO I, we, us, our, you, me, etc can be used anywhere in the lab write-up. How to change a sentence that is written with pronouns: I want to know why these specific environments reduce or enhance an enzyme? Why did these specific environments reduce or enhance the enzyme? If I put an enzyme in a hot, cold, acidic or basic environment, then I believe that the cold environment will have the most effect. If an enzyme is put in a hot, cold, acidic or basic environment, then the cold environment will have the most effect. This sentence should be If an enzyme is tested in a hot, cold, acidic and basic environment, then the cold environment will have the most effect on enzyme activity. to make it a complete sentence.

7 d. Typed (5 points) if any part of the lab is not typed then points will be lost. This includes computer generated graphs. If you cannot get the computer graph to include labels and a title then make your own graph by hand. Things to remember More Formatting: 1. Do not put a title of a section or question on the last line of the previous page then answer or put the information on the next page. 2. Do not handwrite sections on a computer graph. Lab connections: 1. Remember that the objective, variables, and hypothesis all go together and need to match. You also need to keep the wording from the objective in mind and use it when writing your conclusion.

8 2. Your data and your answers to conclusion questions must MATCH. Cold had the most enzyme activity according to the data but was stated as the least in the conclusion. 3. Be sure you understand the terminology and what is a positive and or negative result etc being used in the lab, if you are unsure ask. The observations section of this sample lab and the calculations clearly show that the enzyme works in the basic, cold, and controlled environments and that heat and acid had little or no reaction which means the enzyme IS NOT WORKING.