Plasmolysis " Wet Lab" Exploratory Activity: One of the functions of the cell membrane is to control the flow of materials into and out of the cell. In this investigation, you will observe the effects of placing plant cells in solutions of various concentrations.
Jump to navigation Jump to search Osmosis is defined as the diffusion of water solvent from areas of high solvent more amount of water concentration to areas of low solvent less amount of water concentration across a semi-permeable membrane. We call the liquid with more dissolved solutes in it a hypertonic solution and the liquid with less dissoved solutes is called a hypotonic solution.
If the solutions on both sides of the membrane have the same concentration, it is called isotonic. In osmosis, water moves from a hypotonic solution to a hypertonic solution. All organisms must have strategies to deal with the movement of water into and out of their cells by osmosis.
Plant cells usually have more dissolved solvents inside their cells than the water found in the soil. Because of this, water will rush into the cells.
To prevent the cells from bursting lysisplant cells are surrounded by a hard cell wall. If the plant finds itself in a hypertonic solution, water will rush out of the cells causing the cells to shrivel up.
This process is called plasmolysis.
In this lab we will observe plasmolysis in red onion cells. Make a wet mount of red onion cells. Observe the red cells under the microscope at X and X.
While keeping the slide under the microscope. You may need to pull the liquid across by placing a piece of paper on the opposite side of the slide at the edge of the coverslip.
You may have to refocus the image as the increased liquid will change the location of the coverslip. Explain what happened to the cells. You may do the same using a small slice of potato, if red onion skin is not available.
Alternative 2 only if there is no access to a microscope: Look at this image. Which diagram represents cells in regular blood? Which represents cells in pure water? Which represents cells in a saturated salt solution?
Answer these questions, then look at this article and check your answers. Then write a conjecture about why one's fingers seem "pruny" after a long bath, but not after being in the ocean for an extended time.
· A STUDY OF OSMOSIS. red onion cell, slides, coverslip, compound microscope, 4% salt solution, distilled water, apples, beakers, balance, paper towels. Procedure: 2.
how does this finding correspond to your sweet levels from the sweetness lab? Discussion Questions: 1.
Explain the changes in the size of the vacuole and relative color of kaja-net.com · Web view. Target: Demonstrate Osmosis in a plant cell in a solution of lower concentration of water compared to the onion cell. How: After making a wet mount of a red onion cell, draw a 10% NaCl solution across a slide to cause water to leave the kaja-net.com · LAB _____.
OSMOSIS IN A PLANT CELL PLANT CELL PLASMOLYSIS INTRODUCTION plasmolysis the cell membrane pulls away from the cell wall. In this lab exercise, you will Sketch a single red onion cell in the space below and describe what has happened kaja-net.com · LAB: OSMOSIS IN A RED ONION CELL-DO NOT PRINT THIS PAGE Red DO NOT PRINT THIS PAGE—USE IT AS A REFERENCE TO DRAW THE PICTURES AND ANSWER THE QUESTIONS Step 3 page onion cell in distilled kaja-net.com · -Piece of red onion % salt solution - -distilled water -compound microscope glass slides and cover slips-paper towel 1) Take a small piece of red kaja-net.com · Comparing Plant Cells.
Purpose: Students will observe plant cells using a light microscope. Two cells will be observed, one from the skin of an onion, and the other from a common aquarium water plant (anacharis).kaja-net.com