In this experiment I will be testing the effect of temperature on the plasma membrane of a beetroot. I will do this by measuring the percentage light transmission using a spectrophotometer. Once I have obtained my results, I will justify them using scientific knowledge explaining what I have observed whilst carrying out the experiment.
Factors to be controlled
"« The pH concentration
"« Regular use of distilled water
"« Ensuring that the surface area of each piece of beetroot is the same
"« Use the same volume of water
"« Start with the required temperature before placing the beetroot into the boiling tube.
"« Use a new piece of beetroot for each experimental temperature
"« Ensuring that the boiling tubes are left in the water baths for the same amount of time
Through secondary research I found that if I were to prevent the structure of the protein from altering in any way, I would need to keep the pH level constant. Subsequently, I decided to will be using distilled water throughout the experiment as it has a pH 7 and is neutral; neither acid nor alkali. By surrounding the beetroot with distilled water the protein will not have been altered, and the concentration gradient will be fairly constant for each of the temperatures also. This is because I will be exposing the beetroot to the surroundings of the same type of water, maintaining a fair test as distilled water may contain less or more impurities as other types of water, for example: tap water. I will have to control the amount of distilled water I use to place the beetroot pieces in and control this by using a measuring cylinder. I will measure 15cm3 of distilled water each time. It is important to keep the amount of water constant, as the dilution will affect the rate of diffusion, therefore affecting the results.
Another factor that I will be controlling is the surface area and mass of the beetroot pieces used. This is because the surface area affects the...