This investigation was undertaken in order to observe the effects of changing the temperature of the solution that a potato cube is placed in. The temperatures that were tested in this investigation were 0°C, 20°C (room temperature), and 70°C. This investigation tested the hypothesis:
The rate of osmosis will increase as the temperature increases
2x2x2cm cubes of potato were weighed and then placed into 100mL of 10% NaCl solutions for 10 minutes. After 10 minutes the cubes were again weighed to determine the amount of mass that they lost/gained and thus get an indication of the rate of osmosis. The results collected showed that the rate of osmosis was highest in the 70°C solution and lowest in the 20°C solution. From these results it was concluded that the hypothesis was partially supported as the rate of osmosis was highest in the highest temperature solution, however it was higher in the 0°C solution than it was in the 20°C solution which does not support the hypothesis.
Introduction
The purpose of this investigation is to observe the effects of changing the temperature of the external environment of a plant cell on the rate of osmosis.
In both uni-cellular and multi-cellular organisms, the control of water is vital. Cells contain both water and dissolved solids and for their efficient functioning, cells must maintain the correct osmotic potential. All living organisms consist of cells and all cells are surrounded by a membrane.
One of the cell membranes major functions is to regulate the passage of materials into and out of the cell. Cell membranes are ‘semi-permeable’ which means that some substances can easily pass through them, whereas others cannot. Materials move by simple diffusion from high concentration on one side of the membrane to a lower concentration on the other side. Water is the most abundant and one of the most important substances in cells. The diffusion of water across a membrane is called osmosis. Water will diffuse