Diffusion in Cells Is bigger always better Lab
Diffusion in Cells: Is bigger always better? Lab #8
1) In diffusion, molecules move: a) from low to high concentration b) from high to low concentration c) from an area where there are few to an area where there are many
2) Molecules will move until they are: a) all together in one place b) on one side of a membrane c) evenly distributed
3) Diffusion occurs in: a) Liquid b) Gas c) Both liquid and gas
Diffusion in Agar Cells • Simulation of diffusion into a cell • Agar “cell” put into solution • Indicator in cell will show diffusion of solution into cell (changes color) • Size of cell determines how long it takes for diffusion to complete • Hypothesis: Diffusion will complete fastest in _____ cube 1 cm 2 cm 3 cm
Diffusion in Agar Cells • Each pair will get a 5 x 3 cm “cube” • Use plastic knife to make a 3 x 3, 2 x 2 and 1 x 1 cm cube • Be as precise as possible! 5 cm • Put all three cubes in beaker of solution for a total of 10 minutes 1 cm 3 cm 2 cm
• During the 10 minute wait for diffusion, copy data table below • After 10 minutes cut cube in half and fill in data table Side x Side Length of white area Diffusion depth / 10 minutes Surface area / volume (cm) (cm/min)
1) When the size of a cell increases, does surface area or volume increase faster? 2) Which cube had more surface area in comparison to its volume? 3) Why do cells need to be so small? 4) Why is the endoplasmic reticulum long, skinny and folded?
- Slides: 8
