lab on cell diffusion
Diffusion in Cells
Isabel Zak
Question: How does the size of a cell affect the distribution of chemicals throughout the cell?
Hypothesis: The larger the cell is, the more difficult it will be for the chemicals to reach the centre of the cell, and diffuse throughout it. This is because there will be a higher surface-area to volume ratio in the larger cells, making the centre of the cells further away from the surface. Therefore, when dipped in sodium hydroxide, the larger cells will not be dyed pink all the way through like the smaller cells after the ten minutes.
Materials:
1x1x1 cm agar cube
2x2x2 cm agar cube
3x3x3 cm agar cube
100 ml of sodium hydroxide
Goggles
Petri dish
Scissors
Timing device
Tweezers
Beaker
Graduated cylinder
Procedure: Refer to 'Nelson Science Perspectives 10' pages 38-39, section 2.4; 'What Limits Cell Size?'.
Safety:
All long hair was tied back, and loose clothing was removed. Goggles were worn at all times, and the sodium hydroxide was handled carefully to prevent contact with skin, and was not ingested, as it is poisonous. All of the tests were preformed whilst standing, and in a well-ventilated area. Nothing was eaten or drank during the experiment.
Observations:
Cell
Length of the sides
(mm)
Area of sides
(mm)
Total Surface Area (mm2)
Volume of Cell
(mm3)
Ratio of surface-area to volume
Distance colour extended into cube from surface
Diffusion Rate Per Minute
(depth of dye/time (minutes))
A
10
100
600
1000
3:5
5 mm (all the way through)
.5 mm/minute
B
20
400
2400
8000
3:10
5 mm
.5 mm/minute
C
30
900
5400
27000
1:5
5 mm
.5 mm/minute
Graph:
Ratio of surface-area to volume
Analysis: The colour change in the cells represents how far into the cells the sodium hydroxide was able to diffuse within ten minutes. The sodium hydroxide diffused into the cells at the same rate, .5 mm per minutes. This meant that only the smallest cube, which was 10 mm
Isabel Zak
Question: How does the size of a cell affect the distribution of chemicals throughout the cell?
Hypothesis: The larger the cell is, the more difficult it will be for the chemicals to reach the centre of the cell, and diffuse throughout it. This is because there will be a higher surface-area to volume ratio in the larger cells, making the centre of the cells further away from the surface. Therefore, when dipped in sodium hydroxide, the larger cells will not be dyed pink all the way through like the smaller cells after the ten minutes.
Materials:
1x1x1 cm agar cube
2x2x2 cm agar cube
3x3x3 cm agar cube
100 ml of sodium hydroxide
Goggles
Petri dish
Scissors
Timing device
Tweezers
Beaker
Graduated cylinder
Procedure: Refer to 'Nelson Science Perspectives 10' pages 38-39, section 2.4; 'What Limits Cell Size?'.
Safety:
All long hair was tied back, and loose clothing was removed. Goggles were worn at all times, and the sodium hydroxide was handled carefully to prevent contact with skin, and was not ingested, as it is poisonous. All of the tests were preformed whilst standing, and in a well-ventilated area. Nothing was eaten or drank during the experiment.
Observations:
Cell
Length of the sides
(mm)
Area of sides
(mm)
Total Surface Area (mm2)
Volume of Cell
(mm3)
Ratio of surface-area to volume
Distance colour extended into cube from surface
Diffusion Rate Per Minute
(depth of dye/time (minutes))
A
10
100
600
1000
3:5
5 mm (all the way through)
.5 mm/minute
B
20
400
2400
8000
3:10
5 mm
.5 mm/minute
C
30
900
5400
27000
1:5
5 mm
.5 mm/minute
Graph:
Ratio of surface-area to volume
Analysis: The colour change in the cells represents how far into the cells the sodium hydroxide was able to diffuse within ten minutes. The sodium hydroxide diffused into the cells at the same rate, .5 mm per minutes. This meant that only the smallest cube, which was 10 mm