1. Aerobic Respiration and alcohol fermentation
Bio 201 Lab # 7
Dr. Santos

2. How organisms obtain energy (ATP) for metabolism
Three ways;
Aerobic respiration (uses oxygen) C6H12O6 +6O 6CO2 + 6H /38 ATP
Anaerobic respiration (no oxygen)
Fermentation (partial breakdown of glucose); 2 types alcohol and lactic acid
Alcohol fermentation (only produces 2 ATP)
C6H12O 2CO2 + 2C2H5OH + 2ATP

3. 2 EXERCISES TO DO AEROBIC RESPIRATION EXERCISE
QUESTION; Do germinating peas (growing) undergo more aerobic respiration than dried peas (dormant seeds)?
Hypothesis;_______________________________________________________________
Lets set up an experiment to find out!
Follow the procedure on pages to set up your 2 respirometers!
WE WILL MEASURE THE RATE AT WHICH OXYGEN IS CONSUMED!!!

5. PAGE 55 REVIEW QUESTIONS
Once experiment starts, the peas will start to undergo aerobic respiration, they will use up oxygen gas.
They will release carbon dioxide gas.
The carbon dioxide will react with KOH to form a solid product, KHCO3

6. Exercise 2 Fermentation
C6H12O 2 Pyruvate molecules + 2ATP  2CO acetaldehyde  C2H5OH
Mg+2 is an important cofactor needed by many of the enzymes involved in the above reactions!
The chemical NaF is a respiratory inhibitor in that blocks fermentation by combining with Mg+2 . Without the cofactor, the enzyme changes shape and its noncompetitively inhibited by NaF.
In this experiment you will set up 5 tubes, some will have NaF, which means these should have less fermentation, since you are adding the inhibitor!
The tube with the most fermentation will produce the most Carbon dioxide gas!!!

7. Tube 1- 25 ml yeast /glucose +10 ml of water
Tube ml yeast/glucose + 5 ml water and 5ml inhibitor (0.02M NaF)
Tube ml yeast/glucose + 5 ml water and 5ml inhibitor (0.2M NaF)
Tube ml yeast/glucose + 5 ml water and 5ml cofactor (0.2M MgSO4)
Tube ml yeast/glucose + 5 ml water and 5ml cofactor (0.02M MgSO4)
Incubate for 1 hour!
Follow procedure on Page 57

8. What is expected?
Tube 1 = + reaction Tube 2 = less fermentation than tube 1 since it has the inhibitor Tube 3 = even less than tube 2 since you added a higher concentration of the inhibitor Tube 4 = very good reaction, more than 1 since you added the cofactor! Tube 5 = very good reaction, lots of gas!

9. Review
1- glucose is the starting compound for both aerobic respiration and fermentation
2- germinating seeds take up oxygen
3- carbon dioxide builds up throughout positive reactions
4- the dry seeds are not undergoing aerobic respiration (dormant)
5-the KOH reacts with the carbon dioxide produced forming KHCO3
6- If we performed the experiment without the KOH, the higher level of carbon dioxide will not interfere with the change of volume of gas in the respirometer for the amount of oxygen consumed.