• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5
6. 6
6
7. 7
7

# investigating the water potential of potato cells

Extracts from this document...

Introduction

Internal assignment: Measure water potential of a potato's cells Research question: how is water potential of potato cells differ in different sucrose concentration? Background information: Investigate the water potential of a potato's cells in different sucrose concentrations. The concentrations will be: 0.8M, 0.4M, 0.2M, 0.15M, 0.075M and 0.00M. Terminologies used in this experiment: * Hypertonic solution: solution that has higher osmosis pressure (or has more solutes) than another solution to which it is compared. * Hypotonic solution: a solution that contains less solute (more water) compared to the cytoplasm of the cell. * Isotonic solution: Solutions of equal solute concentration1 * Diffusion: the spread of particles through random motion from regions of higher concentration to regions of lower concentration. * Osmosis: movement of solvent molecules through a selectively-permeable membrane into a region of higher solute concentration, aiming to equalize the solute concentrations on the two sides. It may also be used to describe a physical process in which any solvent moves, without input of energy, across a semi-permeable membrane (permeable to the solvent, but not the solute) separating two solutions of different concentrations * Water potential: potential energy of water per unit volume relative to pure water in reference conditions. ...read more.

Middle

0.75 gram 1.3 Ruler +/- 0.5 mm 2 mm 25 Variables: Controlled variables: * Length of time potato put in sucrose solution * Size of potato cubes * Volume of sucrose solution in a tube (5cm3) * Initial mass of potato cubes * Temperature of experiment's environment Independent variables * Sucrose solution's concentration Dependent variables: * Potato cells' water potential Test's results: Raw data: Raw data of mass of potato tissues (gram) after 15minutes putting in Sucrose solution at different molarity. The initial mass of potato cubes was 0.75 gram exact. Molarity Tube 1 Tube 2 Tube 3 Tube 4 Tube 5 0.8 0.55 0.66 0.60 0.65 0.68 0.4 0.72 0.78 0.70 0.73 0.74 0.2 0.81 0.85 0.82 0.83 0.87 0.15 0.87 0.85 0.84 0.88 0.84 0.075 0.99 0.93 0.90 0.94 0.97 0 1.01 1.17 1.04 1.03 1.10 Quantitative data: At first, when the sucrose solution as just added to the potato cubes, all of them sank. But the cubes floated slowly in the sucrose solution. There are differences between the float of the cubes in different concentration. In the 0.8M concentration, the cubes floated the most. The float of the cubes in other tubes is proportional to the dense of the concentration. ...read more.

Conclusion

This would affect badly on the result of the whole because the water potential of different potatoes' cells is different. Two, the second error is that while putting the potato cubes on the table for a long time without any cover, the water in potato cells evaporated, which might change the water potential of it. Three, while blotting the cubes, I might have blotted them so strongly, this made the water in cells come out, which also lead to the inaccurate. Four, because the amount of potato cubes was big, and we don't have enough time so that we only estimated the size the cubes. The size might not be exact 2mm3 LIMITATION AND SUGGESTIONS Limitations Suggestions Potato cubes stick together, hence the surface of potato cubes in sucrose solution might decrease Shake the tubes contain potato cubes gently and frequently in order to make the cubes separate. Water in potato cells will be lost because of evaporation Put the potato cubes in a box with lid or Petri dish with wrap after cutting. Using different potatoes Use one potato only. If the surround of the potato is dry and turn dark brown, cut it off and use the inner parts. The sensitiveness of digital balance can cause to an imprecise in measuring the potato cubes' masses because just a touch can change the result of a measure. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related International Baccalaureate Biology essays

1. ## The effect of concentration of sucrose solution on the osmosis in potato

PRAC ORDER FORM Method * Cut out 5 pieces from the same potato using a borer and cut the pieces into 2 cm length to give potato pieces around 1 cm3. * Cut the potato with more accuracy using a ruler making and electronic weighting balance to make sure that

2. ## Isotonic Point of Potatoes

Apart from this, the 0.1 M had the highest difference in mass and the second highest in change in length, where the highest was the 0.15M solution, which was a experimental anomaly. The general pattern of data suggested that as the concentration of the solution increased till 0.25M, the change

1. ## Osmosis Lab. Aim: To investigate the effects of different solute concentrations on osmosis, ...

The next graph shows the osmotic pressure of each sampled cup. As told before, the Osmotic pressure helps the inward flow of water in the semi permeable membrane during osmosis. The higher the pressure, the less water is entering into the cell causing it to shrink.

2. ## Osmosis. By this investigation, I tried to find out the changes in potato ...

By saying "wrong mass measuring" I have in mind few possible errors: * Potato cylinders weren't fully drained. That increased potato mass and decreased percentage change in mass. This is clearly seen in 0.0 M and 0.6 M concentrations in both types of potato, less deviation - in 0.2 M.

1. ## Experiment to find the water potential of the cytoplasm of potato cell (Solanum tuberosum ...

strips in 0.3 and 0.4mol Potato (Solanum tuberosum linnaeus) strips in 0.4 and 0.5mol df 4 4 4 4 P value 0.0114 0.0010 0.0240 0.004 T value 4.4300 8.6664 3.5409 10.6236 Ho Reject Reject Reject Reject Concentration of sucrose solution is 0.309 mol0.3mol when water potential of potato (Solanum tuberosum linnaeus)

2. ## sucrose concentration affects potato cells

Leave the potato pieces in the sucrose solutions for 30 minutes. 8. After 30 minutes, take the potato pieces out and dry them 9. Measure the mass of the potato pieces and record them. 10. Repeat steps 2 - 8 for the second and third trial.

1. ## Designing an Osmotic Potential Experiment with Potatoes

tap water into the solution, upon reaching the desired volume I will stop. The sugar must be weighed out first because if I fill the jar with 1l of water and then add another 342.3 grams of sucrose the total volume will exceed 1l.

2. ## How does changing the percentage of sucrose added to yeast affect the rate of ...

As you can see from the graph included below the ?rate peaked when the glucose concentration was at 5% and decreased substantially at the 10%, 20%, and 40%?[2]. This experiment shows what we would expect to occur at extremely high glucose concentrations, namely that the excess glucose would have such

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to