October the 4th
Respiration + Gas exchange
Activity 11.3 (B. Page 143)
A1: Water is needed to be boiled to drive off any dissolved air.
A2: The sugar solution has to be cooled begore adding the yeast, because if not, the yeast would die
A3: The liquid Paraffin’s function is to isolate yeast from air and vice versa.
A4: In the test tube which does not contain liquid paraffin, the substance it’s going to be clear as the yeast is dead and cannot respire. On the other hand, the tube containing liquid paraffin, the substance it’s going to be cloudy aa the yeast is alive and can respire.
A5: The substance we will expect to find is alcohol as it is the result of yeast respiring anaerobically.
Activity 11.8 (B. Page 148)