AIM: How do we write a lab report? December 8, 2014 AIM: How do we write a lab report? Do Now: Using the graph describe how temperature affects the speed at which enzymes work? HW: Transcribe notes Agenda: Do Now/Announcements Go over Quiz Answers Pre-Lab/How to write a lab report
What factors affect the RATE (speed) at which PEPSIN works? Temperature pH
Rate of Enzyme Activity The rate of enzyme activity dependent on temperature: Optimal Temperature Enzyme does not work as well because it begins to lose its shape As temperature rises enzyme activity starts to speed up Most enzymes work best at normal body temperature.
Quiz Answers Enzyme
Quiz Answers
Quiz Answers solution – homogeneous mixture formed when a substance (the solute) is dissolved in another substance (the solvent). Think of a solution like making Kool-aid. You add the powdered Kool-aid into water. What happens when you mix it around? The Kool-aid dissolves into the water. Kool-aid is the solute and water is the solvent. Homogeneous: consisting of parts all of the same kinds Homo = same Heterogeneous: consisting of parts of different kind Hetero = different
Salt Crystals Dissolving in Water Homogenous Solution Salt Crystals Dissolving in Water Water molecules Salt crystal molecules
You will have to write a lab report Lab Tomorrow! You will have to write a lab report Cover page Should include your title, name, and date. You can decorate your cover page for extra credit. Decorations should be inspired by the lab.
You will have to write a lab report Lab Tomorrow! You will have to write a lab report Lab and lab report Due Thursday Must be typed and printed Quiz Friday
Rate of Enzyme Activity The rate of enzyme activity depends on two factors: Temperature Optimal Temperature Enzyme does not work as well because it begins to lose its shape As temperature rises enzyme activity starts to speed up Most enzymes work best at normal body temperature.
The pH scale pH Acid or Base? Example Between 0 and 7.0 7.0 When you measure the pH of a substance, the measurement is a number between 0 and 14. acid base pH Acid or Base? Example Between 0 and 7.0 7.0 Between 7.0 and 14.0 acid neutral base
What would happen if stomach acid were to LEAVE the stomach??? The pH in the stomach is between 1 and 3. ACID! Stomach acid is important in digestion because it: helps to kill bacteria in food allows enzymes (pepsin) in the stomach to work properly. What would happen if stomach acid were to LEAVE the stomach???
Heartburn! Acid Reflux
Heartburn! Symptoms: burning feeling in the chest after eating cough burning in the throat Treatment: TUMS!
Lab Treating Heartburn Problem: What causes heartburn, and how is it treated? Materials: 3 “Mystery” Solutions pH test paper TUMS
3 “Mystery” Solutions A B C Which of these mystery solutions is most similar to the digestive juices in the stomach? Take their pH!
pH Paper
Start Rough Draft of Lab Report On loose leaf start drafting your lab report. Use complete sentences. Purpose Introduce the topic. Give me some background information on the topic. Why is it significant that we are doing this lab? What do you expect to find? Materials Procedure Observations Data/Results Calculations Analysis Conclusion
Lab : Treating Heartburn Procedure: Using the pH paper, take the pH of each of the mystery solutions. Record the pH of each solution in Data Table 1. Determine which mystery solution is most similar to the juices found in the stomach. Pour some of this solution into an empty cup. Use the mortar and pestle to grind up 2 Tums tablets into a powder, and add the powder to this cup. Wait a few minutes, then take use another pH test strip to measure the pH of the solution with Tums. Record this in Data Table 2. Answer the analysis and conclusion questions.
RESULTS Which of the mystery solutions was most similar to stomach acid? What affect did adding the TUMS tablet have on the pH of the mystery solution? Why is TUMS considered to be an “antacid”? Why might it be a bad idea to take too many TUMS?