Practical Report- Diffusion in Agar Cubes
Sabrina Turtur- Stage 1 Biology

Introduction
Diffusion is the movement of particles (atoms, ions or molecules) from an area in which they are in higher concentration to areas of lower concentration. It continues until the concentration of substances is the same throughout. The act of diffusion occurs in respiration, photosynthesis and osmosis. Without it, cells would not receive the nutrients they need to resume stability. Commonly, molecules found within a liquid or a gas will diffuse more efficiently , however, the process of diffusion is altered by a range of permeability, such as the size of the diffusing molecules, the composition of the molecules and the surface area to volume ratio of the substance that the object is disseminating into.

The purpose of the experiment is to find out how the size of the surface area and the volume of a cell can effect the rate of efficiency of a cell diffusing into space. The agar cubes act as cells and the surface area acts as the cell membrane. Each group conducts the experiment so the class average data is as precise as possible. In the experiment, agar cubes with the indicator phenolphthalein are used to determine the diffusion of the cubes. Phenolphthalein is a base/acid indicator that turns clear when in contact with an acid. In this prac, a Sulphuric acid solution is used. When the surface of the agar cube is put in the sulphuric acid, it will become clear, but the insides of the cubes