1. add distilled water to a small beaker and add the agar-agar powder 2. place the agar-agar solution on a hotplate and heat it up 3. add the phenolphthalein solution to the heated beaker 4. turn off the hotplate and allow the beaker to cool, the solution will solidify and form agar lumps (umu) The phenolphthalein-soaked agar balls in front of you can be likened to cells of different sizes 5. place the agar balls in a solution of sodium hydroxide 6. take out the agar balls that have changed color one by one 7. cut the agar balls with a knife 8. observe the agar agar that has turned red
<Result - The larger the piece, the less substance was absorbed in the center - The larger the cells, the less efficient the exchange of substances is - As the agar piece grows larger: the rate of increase in volume is greater than the rate of increase in surface area, reducing the efficiency of mass exchange