Practical 7 Osmosis
Biology Laboratory Report 4
Practical 7
Osmosis
Name: Diana Baktybayeva
Tutorial Group: D
Lab Partner: Nurlan Mukazhanov
Day: Monday afternoon
Date: 17.11.14
Title: Osmosis
Introduction.
Osmosis is a particular type of passive transport involving the movement of water molecules from the region of low solute concentration to the region of high solute concentration through semi permeable membrane, which allows movement of solvent molecules, but not solute. The main principle of osmosis is to equalize the concentration of solute between the cells and their environment (Kent 2000). Generally, there are three different conditions, when the solution is isotonic, hypertonic or hypotonic to the cell. In isotonic solution, when water potential inside and outside the cell is equal, both animal and plant cell behave in the same way: there is no net movement of water. In hypertonic solution, when water potential of the cell is higher than that of the solution, the water molecules will tend to move out of the cell. Hence, the animal cell will shrink, while in the plant cell the cell membrane will move away from the cell wall and cell will become plasmolysed. In hypotonic solution, when water potential inside the cell is lower than that of the solution, water will seek to flow inside the cell. Thus, in plants cell membrane will push against cell wall, causing the cell to become turgid. However, animal cells do not have cell wall and huge gain of water molecules will cause the burst of the cell.
The main purpose of this practical work is to observe the osmosis in potato cubes, onion epidermis cells and visking tubes. To examine the effect of different concentrations of sucrose solutions on the plant cells and dialysis tubings.
Hazards
Precautions
Sharp knife, scalpel, broken glass may cause injuries.
Wear lab coat, gloves and safety goggles during the practical work. Be careful with sharp objects.
Materials and Method.
I. Water potential
Practical 7
Osmosis
Name: Diana Baktybayeva
Tutorial Group: D
Lab Partner: Nurlan Mukazhanov
Day: Monday afternoon
Date: 17.11.14
Title: Osmosis
Introduction.
Osmosis is a particular type of passive transport involving the movement of water molecules from the region of low solute concentration to the region of high solute concentration through semi permeable membrane, which allows movement of solvent molecules, but not solute. The main principle of osmosis is to equalize the concentration of solute between the cells and their environment (Kent 2000). Generally, there are three different conditions, when the solution is isotonic, hypertonic or hypotonic to the cell. In isotonic solution, when water potential inside and outside the cell is equal, both animal and plant cell behave in the same way: there is no net movement of water. In hypertonic solution, when water potential of the cell is higher than that of the solution, the water molecules will tend to move out of the cell. Hence, the animal cell will shrink, while in the plant cell the cell membrane will move away from the cell wall and cell will become plasmolysed. In hypotonic solution, when water potential inside the cell is lower than that of the solution, water will seek to flow inside the cell. Thus, in plants cell membrane will push against cell wall, causing the cell to become turgid. However, animal cells do not have cell wall and huge gain of water molecules will cause the burst of the cell.
The main purpose of this practical work is to observe the osmosis in potato cubes, onion epidermis cells and visking tubes. To examine the effect of different concentrations of sucrose solutions on the plant cells and dialysis tubings.
Hazards
Precautions
Sharp knife, scalpel, broken glass may cause injuries.
Wear lab coat, gloves and safety goggles during the practical work. Be careful with sharp objects.
Materials and Method.
I. Water potential
References: 1. Jane B. Reece and Martha R.Taylor. 2012. Campbell Biology. Pearson press. 2. Michael Kent. 2000. Advanced Biology. Oxford University press.