Biology: Cell Membrane and Test Tube
EXPERIMENT ONE- BIOLOGY MODEL Answers
TO DETERMINE THE EFFECT OF CHEMICALS AND TEMPERATURE ON MEMBRANE DESTRUCTION AND PERMEABILITY IN BEETROOT (Beta vulgaris)
Introduction
The cell membrane is made up primarily of phospholipids and proteins which contribute to its selectively permeable nature. The function and permeability of the cell membrane depends on its intact structure. When destroyed, the permeability of the cell membrane is disrupted causing cellular contents to leak out. The cell membrane can be destroyed by physical damage, chemicals and high temperature. When cells are cut, the cell membranes are mechanically ruptured. High temperature disrupts the structure of proteins and certain chemicals such as fat solvents dissolve the phospholipids, leading to damage of the membrane and therefore increased permeability.
Beetroot contains a red pigment called betacyanin, which is located in the large central vacuole of the beetroot cells. The vacuole is enclosed by a single membrane called the tonoplast and the whole cell is enclosed by the cell membrane made up of phospholipids and proteins. Betacyanin will remain inside the vacuoles of intact cells. However, if the membranes are damaged, betacyanin will leak out and produce a red/dark pink colour in the surrounding water. Cut cylinders of beetroot are used in this experiment. The beetroot cylinders were repeatedly washed following cutting until not more colour appeared in the wash water.
Materials
1. Washed cylinders of beetroot (1 cm in diameter, 4 cm long) in distilled water 2. 3 x test tubes 3. 1 x test tube containing distilled water, cyclohexane and a cylinder of beetroot, labelled TT4. 4. Test tube rack 5. A bottle containing 8 ml distilled water 6. A bottle containing 8 ml 50% acetone 7. A bottle containing 8 ml 100% acetone 8. Permanent marker pen 9. 1x sheet graph paper
Experimental procedure
1. Using the permanent marker pen, label the empty
TO DETERMINE THE EFFECT OF CHEMICALS AND TEMPERATURE ON MEMBRANE DESTRUCTION AND PERMEABILITY IN BEETROOT (Beta vulgaris)
Introduction
The cell membrane is made up primarily of phospholipids and proteins which contribute to its selectively permeable nature. The function and permeability of the cell membrane depends on its intact structure. When destroyed, the permeability of the cell membrane is disrupted causing cellular contents to leak out. The cell membrane can be destroyed by physical damage, chemicals and high temperature. When cells are cut, the cell membranes are mechanically ruptured. High temperature disrupts the structure of proteins and certain chemicals such as fat solvents dissolve the phospholipids, leading to damage of the membrane and therefore increased permeability.
Beetroot contains a red pigment called betacyanin, which is located in the large central vacuole of the beetroot cells. The vacuole is enclosed by a single membrane called the tonoplast and the whole cell is enclosed by the cell membrane made up of phospholipids and proteins. Betacyanin will remain inside the vacuoles of intact cells. However, if the membranes are damaged, betacyanin will leak out and produce a red/dark pink colour in the surrounding water. Cut cylinders of beetroot are used in this experiment. The beetroot cylinders were repeatedly washed following cutting until not more colour appeared in the wash water.
Materials
1. Washed cylinders of beetroot (1 cm in diameter, 4 cm long) in distilled water 2. 3 x test tubes 3. 1 x test tube containing distilled water, cyclohexane and a cylinder of beetroot, labelled TT4. 4. Test tube rack 5. A bottle containing 8 ml distilled water 6. A bottle containing 8 ml 50% acetone 7. A bottle containing 8 ml 100% acetone 8. Permanent marker pen 9. 1x sheet graph paper
Experimental procedure
1. Using the permanent marker pen, label the empty