The Effect of Glucose Concentration on Anaerobic Respiration in Yeast

750 Words3 Pages
The Effect of Glucose Concentration on Anaerobic Respiration in Yeast

Aim:To investigate the effect of glucose concentration on anaerobic

respiration in yeast.

Equipment list:

2* conical flask

Delivery tube with bung

Dropper

Yeast

Glucose

Limewater

Water bath

Stopwatch

Measuring Cylinder

Method:I am going to do 5 tests & each test will be performed 3 times

to get an average result. In one conical flask, I will mix together

25ml of yeast & 25ml of a glucose solution, with a delivery tube with

a bung in the top of it and leave it for 5 min so it gets

acclimatised; in the other conical flask I will put enough water to

cover the end of the delivery tube.

On the first test I will use a 10% concentration of glucose.

On the second test I will use a 15% concentration of glucose.

On the third test I will use a 20% concentration of glucose.

On the fourth test I will use a 25% concentration of glucose.

On the fifth test I will use a 30% concentration of glucose.

I will then put the yeast & glucose mixture in a warm water bath and

count how many bubbles of CO2 are produced within 5 min.

Fair Test:to make it a fair test, I am going to keep the water

temperature, volume of yeast and glucose, concentration of yeast and

the timings constant and the one thing I will change is the

concentration of the glucose so we can tell how the concentration of

glucose effects the respiration of yeast.

Prediction: I predict that the conical flask with the yeast and the

most glucose concentration will respire quickest.

[IMAGE]The conical flask with the yeast and the least glucose

concentration will respire slowest. This is because of the Lock and

Key Theory. Enzymes basically work due to the 'lock and key' theory,

where the substrate (the 'key') fits into the active site on the

enzyme and they bind together, the reaction takes place and the
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