1. Cheese Production—The Evolution of Cheese Making
Lab 1C
Biotechnology Lab Manuel

2. Objectives
Each student performs an individual trial of producing cheese using one of four curdling agents
Students gather, process, and analyze data from multiple replications of cheese made with various agents
Students evaluate the cause and effect of variables in an experiment and attempt to limit variations between trials
Students report experimental findings in a standard conclusion format.

3. Watch Tutorials of Skills
1. Reading Pipets
2. Using Pipets
3. Micro Pipeting
4. P-10 P-20 Micropipeting
5. P-100 P-200 Micropipeting
6. P-1000 Micropipeting

4. Timeline Today: Review Key Concepts and set-up lab
Tuesday: Procedures Quiz, Steps 1-6
Thursday: Steps 7-9, data analysis, start conclusion write-up

5. The World of Cheese Who likes it? How big of a business?
How is it made?
How do you get so many kinds of cheese?
How have Biotechnology improvements in the cheese making process impacted the industry?

6. Biotechnology Impact on Cheese
Look at page 7 and 8 of lab manual
The increasing use of technology includes enzymes: rennin and chymosin

7. Enzyme Info.
No matter the origin, the enzymes are doing the curdling; either bacterial enzymes, fungus enzymes, or enzymes extracted from bacteria, fungi, plant or animal cells.
The enzymes are specialized proteins, are like other proteins, their production is coded for on DNA molecules. Some cells produce milk-curdling enzymes, and others do not, depending upon their DNA code.
Enzyme activity depends on several things:
concentration, temperature, pH, agitation

8. Hypothesis
If we test each of these curdling agents, buttermilk (a bacterial culture starter), rennin, chymosin, and no additional curdling agent (milk is a negative control), which agent do you think will produce the most cheese in the shortest period of time? And why do you think so?

9. Procedures/Flow Chart
Make sure you write your procedures with the tips we discussed last week
Make a flow chart…see example

10. Lab Set-up: Today Set-up stations with everything ACCEPT:
whole milk, buttermilk, rennin and chymosin
1ml pipet and pump (we will use the P-1000 instead)

11. Lab Work: Tuesday (Day 1)
Steps 1-6 Key Points
Measure 30mL of whole milk and take to bench
Bring tubes to front to get .25 mL buttermilk, rennin and chymosin
Looking for curds
If no curds—take home

12. Lab Work: Thursday (Day 2)
Steps 7-9 Key Points
Step 7—let filter for at least 30 min.
Use a lab scoop to get curds out of tube
Folding filter paper demo—don’t tear
Whey-o-meter set-up demo
Calculating curd volume
When finish with your table 1.2, 1 person per group should input it on the front computer

13. Data Analysis
This chart will be filled in by each group, then posted to the website, so you can finish the rest of the write-up and graphs

14. Conclusion/REE, PE, PA REE=Results, Evidence, Explanation
PE=Possible Errors
PA=Possible Application
See page 10 Conclusion for further explanation

15. Witnessing Make sure you get your lab signed by a classmate
See page 6-7 for details

16. Thinking Like a Biotechnician Helpful Hints to get you thinking
temperature, timing, shaking, measurements, etc.
Sufficient would require results to all (or almost all) be similar
Transfer of curds, filter paper absorbtion

17. Bar Graphs You will need to draw (or use excel) bar
graphs for the class averages (4) and then
compare your results to those averages (4).
You will have 8 bar graphs in total. Make
sure to draw your bar graph right next to the
averages. See example

18. Graph Details
A three part title that includes the subject tested, the independent variable and the dependent variable
Proper data-table set-up, independent on the left (x) and dependent on the right (y)
Label and units
Individual entries and averages