14 Catabolism Lab p. 115
is much more efficient than fermentation,
but needs Oxygen, as
O) is released in the citric acid cycle.
- THE EFFECTS OF TEMPERATURE ON THE RATE OF FERMENTATION
- Alcohol fermentation:
C6H12O6 -> 2CH3CH2OH + 2CO2 + energy;
CO2 is released as pyruvate is converted to acetaldehyde.
- Yeast fermentation of sucrose at 3 (not 4) different temperatures for 60 minutes.
Each group needs 75 ml sucrose + 30 ml yeast, divided equally into 3 fermentation tubes.
Make 1 batch of the yeast solution for the whole class: multiply above measures by number of groups.
set oven temperature to low - do not overheat the racks.
- Measure amount of CO2 released into top of fermentation tube.
- MEASURING THE RATE OF OXYGEN CONSUMPTION p. 116
Use Electrolytic Respirometer to measure rate of aerobic respiration.
- EFFECTS OF ACTIVITY ON RESPIRATION RATES IN HUMANS p. 117
Cellular respiration releases CO2 as one of its products,
together with heat.
Carbon dioxide forms carbonic acid
in water: CO2 + H2O -> H2CO3:
this will be measured.
Phenolphthalein as pH indicator: colorless in acid, pink
in neutral or basic (alkaline) solutions.
NaOH to make 100 ml. standard solution with a light - medium pink
Divide this 100 ml. into 2 flasks - one will be your standard, and the other will be the experimental