Osmosis Potential In Potatoes Biology Essay

The intent of this probe is to analyze the consequence of changing the concentration of a sugar solution ( sucrose ) on the sum of osmotic activity between a murphy piece and the solution.

Introduction

Osmosis is a particular type of diffusion which involves the motion of H2O molecules through a partly permeable membrane. Osmosis occurs when H2O moves from an country of a higher concentration ( distilled H2O ) to an country of a lower concentration ( sucrose solution ) . In bend this could be defined as H2O traveling from a weak to a strong solution i.e. the more concentrated sucrose solution.

Figure 1 – Osmosis

Across the partly permeable membrane a concentration gradient exists. Water molecules are able to travel in any way through the partly permeable membrane. On the right side of the membrane there is a higher concentration of H2O therefore there will be an overall motion of H2O to the left.

The H2O molecules pass through the partly permeable membrane until each side has the same concentration degree.

Osmosis

Osmosis in workss cells

In workss cells H2O moves in and out of them depending on the concentration of the solution environing the cells. As works cells have to the full permeable cell walls this allows anything dissolved to go through through. The cell wall prevents excessively much H2O come ining and in bend spliting due to osmotic force per unit area. When H2O moves into a works cell the vacuole within additions in size and pushes the cell membrane against the cell wall. As a consequence, the force of the membrane forcing against the cell wall makes the cell wall turgid. ( In consequence the osmotic force per unit area is responsible for maintaining herbaceous ( non-woody ) workss unsloped ) . Plant cells which do non have adequate H2O consequences in wilting happening hence do the works flaccid. During osmosis if a works loses excessively much H2O it consequences in plasmolysis occurring.

Figure 2 – Plant cells under different environments

If a works cell was surrounded by a concentrated solution, with a lower H2O concentration than the cell this would ensue in the cell losing H2O by osmosis. This would be defined as hypertonic.

If a works cell was surrounded by a solution with the same concentration as the cell there would be no overall motion of H2O across the cell membrane. This would be defined as being isosmotic.

If a works cell was surrounded by a dilute solution, which would hold a higher concentration of H2O than the cell so the cell would derive H2O from osmosis. This would be defined as being hypotonic.

Hypothesis

As osmosis is defined as the motion of H2O molecules across a partly permeable membrane from an country of high H2O concentration to an country of low H2O concentration, I predict that as the H2O concentration decreases in the murphy pieces the overall mass and length will diminish excessively. ( As the sucrose solution concentration is increased the more obvious the alteration in mass and length will be in the murphy piece ) . I besides predict that by the terminal of the experiment the murphy piece in the distilled H2O ( 0M ) will weigh the most as in osmosis the H2O from outside the cells will come in the vacuole to thin it as the cells have a stronger solution in them. Therefore the cells will go full of H2O and as a consequence will go bombastic.

During the experiment, the little holes within the membrane of the murphy piece will let the H2O molecules to go through through in and out of solution and the murphy piece. This depends on the concentration of the solution.

In the 0 molar – distilled H2O solution, the H2O will come in the murphy piece because it is of a higher H2O concentration than the liquid inside the cell of the murphy piece. As a consequence the murphy should increase in weight and length. This may besides ensue in the murphy piece going bombastic as the solution environing the murphy piece is of a weaker concentration.

In the 0.2 grinder concentrated solution, I believe there will be a smaller sum of alteration in footings of the murphy pieces ‘ weight. This is because the concentration of the solution and the cell of the murphy piece are really similar. I think there will be a little addition in weight of the murphy piece.

In the 0.4 grinder concentrated solution, I predict that the murphy piece will diminish in weight due to the rise in concentration of the sucrose solution. Although I do believe the consequence will merely diminish by a little sum as the concentration of the solution and the cell of the murphy piece are still rather close.

In the 0.6 grinder concentrated solution, I believe there will be an obvious lessening in the weight of the murphy piece. This is due to there being a higher concentration within the murphy cell than of the sucrose solution.

In the 0.8 grinder concentrated solution, I believe there will be similar consequence to that of the 0.6 grinder but there will be a more noticeable weight loss.

In the 1 grinder concentrated sucrose solution, I think there will be the most seeable alteration in weight loss of the murphy piece compared to the old 0.8, 0.6, 0.4, 0.2 and O molar solutions. This is because the solution environing the murphy piece is of a much higher concentration than within the murphy cell, which consequences in more H2O come ining the cell sap of the murphy piece.

There are besides the proposed variables involved that will let me to be after and explicate the experiment carefully, they are outlined below:

The Independent variable: The independent variable is what I intend to alter in the experiment, which in this instance will be the concentration of each solution, as stated antecedently from 0 grinder to 1 grinder. The ground for altering the concentration is to see the consequence it has on the murphy piece when placed in a sucrose solution of different molar concentrations.

Dependent Variable: The dependant variable is what I will be mensurating during the osmosis experiment, which will be the alteration in mass and length of each murphy piece. I will be entering the mass before and after the experiment utilizing graduated tables, and I will enter the length before and after the experiment utilizing a swayer.

Controlled Variables: When transporting out the experiment I intend to do the trial carnival by commanding the variables. I will be mensurating each murphy piece with a swayer to guarantee each is of an equal length ( 2cm ) . I will utilize the same sum of solution in which each murphy piece will be placed into ( 10ml ) . I will besides be utilizing the same type of murphy during the experiment to avoid any anomalous consequences as a different murphy may impact the rate of osmosis. Finally I be carry oning the experiment at room temperature.

Preliminary consequences

The preliminary trial was conducted utilizing six equal lengths of murphy pieces and puting each in a varying sucrose solution from a high concentration to a low concentration ( distilled H2O ) . Each murphy piece was measured in length and mass before the trial was conducted in order to enter the terminal consequences.

During my first preliminary trial I made the error of non mensurating the mass and merely the length of the murphy piece. From this I was able to larn how to transport out the trial decently. Below is the consequence of the 2nd preliminary trial:

Solution – Molar

Weight Before ( g )

Weight After ( g )

Change in weight ( g )

Length Before ( centimeter )

Length After ( centimeter )

Change ( centimeter )

A – 1.0

0.44

0.39

– 0.05

1

1

— — — — — — —

B – 0.8

0.45

0.41

– 0.04

1

1

— — — — — — —

C – 0.6

0.45

0.42

– 0.03

1

1

— — — — — — —

D – 0.4

0.44

0.43

– 0.01

1

1

— — — — — — —

E – 0.2

0.43

0.47

0.04

1

1

— — — — — — —

F – 0

0.44

0.50

0.06

1

1

— — — — — — —

From the tabular array above I can reason that as the sucrose solution concentration was increased the overall weight loss had increased excessively. In bend the more H2O concentrated the solution, the more addition in weight. There were no seeable alterations in length as a consequence of the increased sucrose concentration.

As a consequence of my preliminary trial I will be altering the length of the murphy pieces to 2cm alternatively of 1 centimeter as this will give me a better scope of consequences in order to pull up decisions.

Apparatus

Below is the list of setup used to carry on the experiment:

Safety goggles

Test tubing rack

1 Cork bore bit

6 trial tubings

Measuring cylinder

Cuting tile

Ruler

Timer

Scales

Sucrose solutions

Distilled H2O

Potato

Fair Test

In order to do my experiment a just trial I had to guarantee that the same method was used through each of the three experiments. During the experiment I had to alter one key variable which was to change the concentration of the sucrose solution. This was to let a varied scope of consequences in order to pull up a decision on the experiment. When transporting out the experiment I made certain to lodge to the undermentioned variables:

During the experiment I worked at room temperature

I used the same type of murphy throughout the experiment.

I measured precisely 10ml of solution for each trial tubing to guarantee the same volume of solution was used.

The murphy piece was cut to 2cm utilizing a swayer in order to maintain the lengths of the murphy pieces the same.

The mass of the murphy piece was a dependent variable so I measured the weight of each murphy piece utilizing graduated tables before carry oning the experiment.

The experiment was timed utilizing a timer for 30 proceedingss to guarantee complete and accurate consequences.

The mass of each murphy piece was measured after the experiment to see if osmosis had taken topographic point.

The length of each murphy piece was measured after the experiment to see if osmosis had taken topographic point.

Method

Gather the setup needed for the probe.

Using a cork bore bit step out six equal pieces of murphy.

Using a swayer cut each piece of murphy to a length of 2cm.

Fill five trial tubing with 10ml of five changing strengths of sucrose solution.

Fill the 6th trial tubing with 10ml of distilled H2O.

Topographic point the six trial tubings into a trial tubing rack.

Label each trial tubing from A to F, A being the highest concentration to F being distilled H2O. This is to separate each changing strength of the solution in order to hold accurate consequences.

Using graduated tables weigh each piece of murphy and record the weight.

Place one murphy piece into each of the trial tubing.

10. Get down the timer and clip for 30 proceedingss.

11. After 30 proceedingss take each murphy monetary value out of the remainder of

the trial tubing.

12. Using the graduated tables, weigh each murphy piece and record the

new weight.

13. Record the consequences in a consequences tabular array.

14. To guarantee truth reiterate the experiment twice, this will

give a varied tabular array of consequences.

15. From the consequences plot a graph.

Diagram

Solution

Test tubing

Potato bit

1 Molar

Distilled Water 0.2 Molar 0.4 Molar 0.6 Molar 0.8 Molar

( 0 Molar )

Observations

During the experiment I noticed that the murphy pieces of which were placed in the most concentrated sugar solution by and large floated to the top of the trial tubing.

Consequences Table

Solution

Weight Before ( g )

Weight After ( g )

Change in Weight ( g )

Average weight ( g )

Length Before ( centimeter )

Length After ( centimeter )

Change in Length ( centimeter )

Average length ( centimeter )

1

2

3

1

2

3

1

2

3

1

2

3

1

2

3

1

2

3

A – 1.0

0.56

0.61

0.59

0.51

0.54

0.54

– 0.05

– 0.07

– 0.05

– 0.06

2

2

2

1.9

1.9

1.9

– 0.01

– 0.01

– 0.01

0.01

B – 0.8

0.60

0.56

0.59

0.52

0.56

0.55

– 0.08

— — — — –

– 0.04

– 0.04

2

2

2

1.9

1.9

1.8

– 0.01

– 0.01

– 0.02

0.013

C – 0.6

0.57

0.53

0.60

0.55

0.51

0.55

– 0.02

– 0.02

– 0.05

– 0.03

2

2

2

1.9

1.8

1.9

– 0.01

– 0.02

– 0.01

0.013

D – 0.4

0.58

0.62

0.59

0.55

0.62

0.57

– 0.03

— — — — –

– 0.02

– 0.02

2

2

2

1.9

2.0

2.0

– 0.01

— — — — –

— — — — –

0.003

E – 0.2

0.61

0.59

0.63

0.63

0.61

0.64

+ 0.02

+ 0.02

+ 0.01

0.02

2

2

2

2.0

2.0

2.0

— — — — –

— — — — –

— — — — –

0

F – 0

0.56

0.60

0.53

0.60

0.63

0.58

+ 0.03

+ 0.03

+ 0.05

0.04

2

2

2

2.0

2.0

1.9

— — — — –

— — — — –

– 0.01

0.003

Graph

Decision

From my consequences table I can see the consequence of osmotic activity within the murphy pieces by H2O molecules traveling through a partly permeable membrane which exists across the concentration gradient. The molecules move into an country of lower concentration which in this instance is the sucrose solution because osmosis merely takes topographic point from an country of high H2O concentration to an country of low H2O concentration. The more osmotic activity which took topographic point resulted in the murphy pieces diminishing in length and weight. From the graph you can see that the pieces of murphy which were placed in a 0.2 molar concentration or less increased in weight and length and those placed in a 0.4 molar concentration or higher decreased in weight and length.

As stated in my hypothesis I predicted that there would be a lessening in weight and length. As the murphy cell was surrounded by a more concentrated solution this resulted in there being a lower H2O concentration within the murphy cell which meant osmosis took topographic point doing it hypertonic. As predicted my consequences were right the murphy pieces which were more H2O concentrated weighed more compared to the murphy pieces which were in a more sucrose concentrated solution.

Evaluation

Overall I feel that the experiment went good as there no major anomalousnesss during the experiment. I think the method that was used to carry on the experiment was really suited as it was n’t excessively clip devouring and it was easy to transport out. It was besides a good method to utilize because it gave me dependable and accurate consequences in order to pull up a decision. The preliminary trial besides allowed me to be after out how I would transport out the existent experiment and if I needed to do any alterations such as the length of the murphy piece which was increased to 2cm alternatively of 1cm.

However if I were to transport out the experiment once more there would be a few things that I would alter. When transporting out the experiment I used a scope of 0, 0.2, 0.4, 0.6, 0.8 and 1 molar solution to see the consequence of osmosis in the murphy pieces. In the hereafter I would wish to hold more varied scope of the concentration of the solution in order to bring forth a more varied scope of consequences i.e. 0, 0.1, 0.2, 0.3… There was an anomalous consequence as shown on the consequences graph as the 0.4 molar solution was farther off from the line of best tantrum. This may hold been due to the fact that the murphy piece was dried more compared to each other murphy piece therefore this would ensue in a more noticeable lessening in mass i.e. it went from a 0.02 addition in mass in the 0.2 grinder to a 0.02 lessening in mass in the 0.4 grinder. As a consequence in transporting out any future experiments I would do certain each murphy piece is dried under the same sum of clip and method. I would besides go forth the murphy pieces in the solution for a longer length of clip as they were merely in the trial tubing for 30 proceedingss. I would see altering the clip to 60 proceedingss as I feel at that place would be a more noticeable scope of consequences hence better decisions could be drawn up. There would besides be a great advantage to reiterating the trial 5 times alternatively of 3 as this would change the consequences even further.

– In the figure 1 visking tubing there is a much higher concentrated solution than the solution environing the visking tubing inside the beaker which is distilled H2O. As a consequence this means the sum of liquid inside the visking tubing will lift through osmosis.

– In the figure 2 visking tubing there is a much lower concentrated solution than the solution environing the visking tubing inside the beaker which is a sucrose solution. As a consequence the degree of liquid inside the beaker will lift through osmosis.

In the hereafter I would besides see making a different type of experiment such as visking tubing. Visking tube is a partly permeable membrane which is made from regenerated cellulose which allows little molecules like H2O to go through through but does n’t let big molecules to go through through such as glucose because they are excessively large to spread out into the H2O. When a visking tubing is placed into a beaker, which is filled with distilled H2O, the H2O molecules will go through from the beaker into the visking tubing which will thin the sucrose solution. The visking tubing is attached to a glass tubing ; this allows the rise of H2O to be seen from the glass tubing when H2O is traveling from the beaker into the visking tubing.