Difference between revisions of "GCSE Biology Required Practical: Decay of Organic Material"
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Investigate the effect of [[temperature]] on the [[decay]] rate of organic material. | Investigate the effect of [[temperature]] on the [[decay]] rate of organic material. | ||
===Method=== | ===Method=== | ||
| − | *[[Independent Variable]] - | + | *[[Independent Variable]] - Temperature of organic material. |
| − | *[[Dependent Variable]] - | + | *[[Dependent Variable]] - pH of milk. |
| − | *[[Control Variable]]s - | + | *[[Control Variable]]s - Volume of milk, volume of indicator solution. |
| − | # | + | #Fill a 500ml beaker with 250ml of hot water which will act as a water bath. |
| + | #Place 5cm<sup>3</sup> of lipase into a testube using a pipette. | ||
| + | #Place 5cm<sup>3</sup> of milk into another test tube using a pippette with 5 drops of 'Cresol Red' solution. | ||
| + | #Add 7cm<sup>3</sup> of sodium carbonate solution to the milk in the test tube. | ||
| + | #Place both test tubes in the water back and a thermometer into the milk test tube. | ||
| + | #Once the milk mixture has reached the temperature of the water bath add 1cm<sup>3</sup> of lipase to the mixture and start a timer. | ||
| + | #Stir throughout then record the time taken for the for the solution to turn yellow. | ||
| + | #Repeat this using different temperatures of water in the beaker. | ||
Revision as of 17:23, 22 November 2018
Key Stage 4
Meaning
Investigate the effect of temperature on the decay rate of organic material.
Method
- Independent Variable - Temperature of organic material.
- Dependent Variable - pH of milk.
- Control Variables - Volume of milk, volume of indicator solution.
- Fill a 500ml beaker with 250ml of hot water which will act as a water bath.
- Place 5cm3 of lipase into a testube using a pipette.
- Place 5cm3 of milk into another test tube using a pippette with 5 drops of 'Cresol Red' solution.
- Add 7cm3 of sodium carbonate solution to the milk in the test tube.
- Place both test tubes in the water back and a thermometer into the milk test tube.
- Once the milk mixture has reached the temperature of the water bath add 1cm3 of lipase to the mixture and start a timer.
- Stir throughout then record the time taken for the for the solution to turn yellow.
- Repeat this using different temperatures of water in the beaker.