• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Investigating the relationship between cell size and rate of diffusion

Extracts from this document...


Investigating the relationship between cell size and rate of diffusion Aim: To plan and carry out an investigation to show the relationship between volume, surface area, and diffusion; and to demonstrate, using diffusion, why the size of cells is limited. Hypothesis: In this experiment, I expect to find that when the surface area to volume of a cell reaches a certain level, diffusion alone won't be able to supply the cell materials needed, and as single-celled organisms take in and release substances by means of diffusion across the cell membrane, this process limits cell size. I predict that as the rate of diffusion will be too slow to deliver materials to the center of the cell in the larger cells, it could result in cell malfunction. ...read more.


3. After around 10 mins. cut one of the smaller cubes in half to see if the color has reached the middle of the cube. If it has then stop the investigation, take out all cubes and rinse them in water. In not, allow the investigation to carry on for a reasonable period of time and then stop the investigation. 4. Once all cubes are taken out, cut them all in half and measure the area which has changed pink with a ruler. 5. Record all the data in a raw data table. Diagram: Results: We did the experiment twice, as to get a range of data, however we got the same results both times. SA (cm ^2) Volume (cm^3) Simplest ratio 3 cm agar cube 6(3x3)= 54 cm^ 2 (3x3x3)= 27 cm^3 2 : 1 2 cm agar cube 6(2x2)= 24 cm^2 (2x2x2)= 8 cm^3 3 ...read more.


When cells grow to a certain size, their rate of growth slows down until they have stopped growing completely (restrains cell size). Once a cell has reached its size limit, and when one of the larger cells divide into smaller ones, the rate of growth again increases. So generally, the relationship between the rate of diffusion and cell size is that the rate of diffusion stays the same, but as all the cells are small, diffusion occurs quicker throughout the cells, than in larger cells. Even though we used agar jelly containing pH indicator to represent a cell and NaOH to represent the state of simple diffusion, this really is the process that occurs millions of thousands of times in our bodies. As the single-celled organisms take in and release substances by means of diffusion across the cell membrane which is important to their successful function, this is the reason that there is a limit to cell size. ...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

Here's what a teacher thought of this essay

The investigation does not really address the central question of the effect of surface area to volume ratio in enough detail.

Too much focus is placed on the calculation of the surface area to volume ratio and its relationship with the size of the cube.

The data from the experiment is missing.

The discussion does approach the reason why a high surface area to volume ratio is important as it allows faster diffusion rates which is vital for cell functioning. It does not really explain that the more surface area that is available compared to volume means that there is more of its volume exposed to the outside environment and that this increases diffusion rate.

Marked by teacher Jon Borrell 22/05/2013

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

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Marked by a teacher

    Osmosis Internal Assessment (Biology)

    4 star(s)

    Using a cylindrical borer, bore 5 cylindrical strips (1cm in diameter) out of a Potato. 4. Using the ruler, measure each strip and cut into pieces that are 4 cm long. 5. Place each potato strip on a fresh paper towel to drain off excess juices.

  2. Biology IA - Investigation of the relationship between surface area and volume using different ...

    Size of cube (cm) Cm diffused from walls Rate of diffusion (cm/min) 1. 1x1x1 0.5 0.05 2. 1x2x4 0.5 0.05 3. 2x2x2 0.5 0.05 4.

  1. Effect on temperature on the rate of transpiration of HIbiscus sp

    5. Pull the syringe and adjust the air bubble to 0. 6. Wait for about 1 minute and allow it to equilibrate. 7. Measure the distance moved by the air bubble along the scale on the potometer in 1 minute and collect data.

  2. Biological Membrane Lab

    1 - This table describes the data we collected in our individual group(s). Methanol Concentration (%) Group 1 Group 2 Group 3 Group 4 Average 0 0.128 0.130 0.061 0.104 0.105 10 0.124 0.138 0.068 0.104 0.108 20 0.103 0.112 0.069 0.104 0.097 30 0.170 0.145 0.071 0.104 0.122 40 0.112 0.163 0.079 0.104 0.114 Ethanol Concentration (%)

  1. Factors affecting the rate of transpiration

    would increase. When the leafy shoot will be placed in dark conditions there will be a significant decrease in the amount of water uptake by the shoot, thus resulting in a lower transpiration rate. The third hypothesis that will be tested is that when half the leaves are removed, there

  2. Ecology Open Investigation Does the geographic location affect the biotic and abiotic ...

    Aquatic macroinvertebrates have different tolerance levels to water pollution therefore in this investigation macroinvertebrates will be used as bioindicators thus also allowing the healthiness of the waterways to be determined. [4] Focus Question: Does the geographic location affect the biotic and abiotic factors in Brown Lake and 18 Mile Swamp located on North Stradbroke Island.

  1. What is the effect of increasing pH concentration (pH 3, 4, 5, 6 and ...

    Length of stem (±1cm) Number of leaves(±1) Color of leaves p H 6 Day 1 0.45 - - - Day 3 1.41 1.76 20 Green Day 5 2.51 2.43 24 Green Day 7 3.35 3.58 28 Green p H 7 Day 1 0.81 - - - Day 3 1.81 1.75

  2. An experiment to determine the effect of caffeine on heart rate

    This can be done so by placing two fingers on the neck or placing two fingers on the opposite wrist. Record this data in a table. Start off with the 25ml of Bison. Drink this volume of Bison and start the stopwatch.

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