Investigating the concentration of Glucose inside Cell sap in potatoes Through Osmosis.

Essay by xSnuffxHigh School, 12th grade May 2004

download word file, 4 pages 2.3

In the following experiment I will be investigating the concetration of glucose in the cell sap of a potato cell by weighing the samples of potato before and after soaking them in a concetrated glucose solution. I predict, that the stronger the solution of glucose, the more weight the piece of potato will lose, and when placed in a more dilute glucose solution, the potato will gain weight.

This is due to Osmosis, the movement of water molecules from an area of high concetration to an area of low concentration. The cell membranes are permeable to water, and so if the glucose concentration inside the cell is more concentrated than the solution it's placed in, water molecules will pass through the cell wall to the solution, causing the potato to gain weight.

For this experiment I will be using small cylinder shaped pieces of potato, 5cm long, and cut with a cork borer to ensure the same width for each piece.

I will be finding out the concentration of glucose inside the cell sap by controlling the same amounts of different glucose solution of a different concentration. I will be weighing the mass of the potato before and after placing it in the glucose solution, and measuring the amount of weight gained, or lost, once soaked for exactly ten minutes.

Equipment

Stopwatch

Cork Borer

Ruler

Electronic Weighing Scales

Measuring Beaker

Petre Dishes

I will be making my test as fair as possible, by ensuring I have enough data to note down the average results. I will be doing this by placing three pieces of potato into each petre dish filled with the same amount of desired concetrated glucose solution. All three pieces must be exactly the same size, and so I will be measuring to make sure the length...