Membrane Permeability
Title Membrane Permeability
Aim To determine the effect of various chemicals and high temperature on the membrane permeability of beetroot
Hypothesis Organic solvent and high temperature will destroy the cell membrane and make it permeable to the red pigment. The higher the concentration of the alcohol, the greater will be this effect.
Principle
Beetroot is the material used in this experiment to demonstrate the effects of high temperature and chemicals on the permeability of the cell membranes. Beetroot contains a red pigment called betalain, which is located in the large central vacuole of the beetroot cells. The vacuole is enclosed by a single membrane called tonoplast and the whole cell is enclosed by cell membrane made up of phospholipids. As long as the cells and their membranes are intact, the betalain will remain inside the vacuoles. However, if the membranes are damaged, betalain will leak out and produce a red colour in the water surrounding. More cells being damaged will cause a higher red colour intensity in the solution.
Cell membrane is made up of a bimolecular leaflet of phospholipids, which contains hydrocarbons and phosphate. Protein molecules can also be found embedded within and attached onto the surface of the membrane. The selective permeability of cell membrane can be easily destroyed by certain chemicals and high temperature because the function of a protein molecule depends on its structure, which is easily denatured.1. High temperature and alcohols denature membrane proteins, and increase fluidity of membrane lipids. 2. Alcohols at high concentrations can also dissolve phospholipids and as dehydrating agent to extract water form the cell. 3. Lipid (organic) solvents like chloroform and ether dissolve the lipid molecules of the membrane and thus increase permeability.
Independent variables: different types of organic solvent and water in different temperature the beetroot tissue immersed into for a fixed period of time.
Aim To determine the effect of various chemicals and high temperature on the membrane permeability of beetroot
Hypothesis Organic solvent and high temperature will destroy the cell membrane and make it permeable to the red pigment. The higher the concentration of the alcohol, the greater will be this effect.
Principle
Beetroot is the material used in this experiment to demonstrate the effects of high temperature and chemicals on the permeability of the cell membranes. Beetroot contains a red pigment called betalain, which is located in the large central vacuole of the beetroot cells. The vacuole is enclosed by a single membrane called tonoplast and the whole cell is enclosed by cell membrane made up of phospholipids. As long as the cells and their membranes are intact, the betalain will remain inside the vacuoles. However, if the membranes are damaged, betalain will leak out and produce a red colour in the water surrounding. More cells being damaged will cause a higher red colour intensity in the solution.
Cell membrane is made up of a bimolecular leaflet of phospholipids, which contains hydrocarbons and phosphate. Protein molecules can also be found embedded within and attached onto the surface of the membrane. The selective permeability of cell membrane can be easily destroyed by certain chemicals and high temperature because the function of a protein molecule depends on its structure, which is easily denatured.1. High temperature and alcohols denature membrane proteins, and increase fluidity of membrane lipids. 2. Alcohols at high concentrations can also dissolve phospholipids and as dehydrating agent to extract water form the cell. 3. Lipid (organic) solvents like chloroform and ether dissolve the lipid molecules of the membrane and thus increase permeability.
Independent variables: different types of organic solvent and water in different temperature the beetroot tissue immersed into for a fixed period of time.