Diffusion

Selectively Permeable Membrane

Animal Cell (Normal Saline 0.9%) = solute

Activity 1 Diffusion experiment Methylene blue MW 320g/mole Potassium permagnate MW 150 g/mole Form Hypothesis T0 initial diameter T60 final diameter Calc. rate of diffusion Room temp

Table 1. Rate of Diffusion in Methylene Blue vs Potassium Permagnate at Room Temp Time MB RT PP RT T0 10 mm T60 20 mm 10 mm/hr

Table 2. Rate of Diffusion in Methylene Blue vs Potassium Permagnate at Room Temp Group Data MB RT PP RT 1 10mm/hr 8 mm/hr 2 3 4 5 Ave SD

Activity 2 Osmosis through semipermeable membrane Create 4 dialysis bags, filled with unknown concentration sucrose solutions (10 ml) Weigh bags and then immerse in 10% sucrose solution (50 ml) Reweigh bags after 30 minutes of experiment Identify the bags containing 0%,10%, 20%, and 40% of sucrose, based on weight changes.

Unknown solutions of sucrose (0, 10, 20 & 40 %) 10 ml of unknown sucrose into dialysis bag

Dialysis Tubing Open tubing with water Tie knot at one end Fill with one of the unknown solutions (10ml) Tie other end

10 ml of unknown sucrose into dialysis bag

Weigh pre and post

Place dialysis bag in 50 ml 10% sucrose for 30 minutes