1. 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

2. What factors affect the RATE (speed) at which PEPSIN works?
Temperature pH

3. 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.

4. Quiz Answers
Enzyme

5. Quiz Answers

6. 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

7. Salt Crystals Dissolving in Water
Homogenous Solution
Salt Crystals Dissolving in Water
Water molecules
Salt crystal molecules

8. 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.

9. 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

10. 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.

11. 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

12. 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???

13. Heartburn!
Acid Reflux

14. Heartburn! Symptoms: burning feeling in the chest after eating cough
burning in the throat
Treatment:
TUMS!

15. Lab Treating Heartburn
Problem: What causes heartburn, and how is it treated?
Materials:
3 “Mystery” Solutions
pH test paper
TUMS

16. 3 “Mystery” Solutions A B C
Which of these mystery solutions is most similar to the digestive juices in the stomach?
Take their pH!

17. pH Paper

19. 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

20. 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.

21. 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?