Find out the concentration of the cell contents of a potato

Satisfactory Essays
Find out the concentration of the cell contents of a potato

Introduction

Osmosis is the diffusion of water from a lower concentration of solute

to a higher concentration of solute through a partially permeable

membrane. This lets smaller molecules such as water, pass through but

does not allow bigger molecules through. The molecules continue to

diffuse until they reach a balanced state, where no area has a higher

or lower concentration than any other.

In a high concentration of water the amount of sugar solution is low.

This is called a weak/dilute solution. In a weak concentration of

water the amount of sugar solution is high. This is called a

strong/concentrated solution.

When a semi-permeable membrane divides two solutions, the water will

move from the area of high concentration to the area of low

concentration, until both sides are equal.

Aim

To find out how much sugar concentration there is in a cell of a

potato. This means I will put the potato cylinders in different

solutions of different concentrations.

There are also other factors involved, these are:

· Temperature of water

· Size of potato cylinder

· Mass of potato cylinder

· Volume of solution potato cylinder is in

· Type of potato

· Time left in solution

Fair Testing

If this experiment isn’t a fair test, we will be collecting the wrong

results, which can lead us to the wrong conclusions. To conduct a fair

test I will ensure that the experiment is carried out at room

temperature. The size of the potato is an important factor, as the

amount of weight lost or gained will alter. Also the potato cylinders

will be weighed before and after the experiment to see if osmosis has

taken place. The type of potato I will use will stay the same as

different potatoes may absorb at different rates.

Planned Method

A range of sugar solutions will be arranged with concentrations……………..

Sections of potato will be cut with a scalpel and measured with a

ruler. This has to be done carefully as the difference of surface area

may allow more or less osmosis to occur. The mass of each cylinder

will be weighed to ensure consistency. I will do each experiment three

times so that I can take an average for each sugar solution. By doing

this I will receive more accurate results and therefore draw up a more

accurate conclusion. I will also use 20 ml of each solution and of

tap water. The potato cylinders will then be left for 15 minutes. When

the cylinders are removed I will clean them with a paper towel, to

remove excess moisture, and then re-weigh them.

Prediction

For this investigation, I think the lower the concentration of the