Explain the effects of a semipermeable membrane like the cell membrane on movement by solutes and water. Distinguish diffusion and osmosis. 2. Explain the effects of a semipermeable membrane like the cell membrane on movement by

Explain the effects of a semipermeable membrane like the cell membrane on movement by solutes and water. Distinguish diffusion and osmosis. 2. Explain the effects of a semipermeable membrane like the cell membrane on movement by

Objectives: Students should learn to: 1. Distinguish diffusion and osmosis. 2. Explain the effects of a semipermeable membrane like the cell membrane on movement by solutes and water. 3. Define the terms isotonic, hypertonic and hypotonic. 4. Predict and explain the movement of starch, protein, sulfate ions and chloride ions across the semipermeable pores of a dialysis tubing. Diffusion is the movement of substances from a high concentration to a low concentration. It comes about because the molecules of the substance move anyway randomly in all directions all the time. For example, perfume molecules in air move randomly in all directions all the time. Therefore, if more perfume molecules are present in one area, more will move randomly to the other area with less perfume molecules than the other way around. Osmosis is the movement of substances by diffusion when it occurs through a semipermeable barrier. A barrier is semipermeable, when it lets some substances pass but others not. A semipermeable barrier might let water pass but not the other substances that are dissolved in water. The substances that are dissolved in water are called the solutes, whereas water is then called the solvent. In osmosis when only water can pass the semipermeable barrier, just like in general diffusion, more molecules of water will pass through the barrier to the side where its concentration is lower than the other way around. The concentration of water is lower, where it contains more solutes. Note that movement of water by osmosis is a spontaneous movement that requires no energy. It happens “on its own.” The rate at which this movement occurs depends on many factors, including the relative concentration of water on each side, and temperature, among others. In biology, we are generally concerned with osmotic movement of water in and out of cells across cell membranes. Cell membranes are the semipermeable barriers around our cells that allow water to pass unhindered but that prevent many of the solutes dissolved in water from passing. Cell membranes though can be permeable to some important other molecules than water. In lab, we will investigate how a semipermeable membrane functions by using a dialysis tubing as our example. A dialysis tubing has tiny holes that let small molecules pass but not large ones. We will investigate whether starch, protein, sulfate ions and chloride ions pass the holes in the dialysis tubing. Do you know the relative sizes of these four compounds? Can you formulate a hypothesis as to which of them you expect to pass the dialysis tubing and which not? Write down your hypothesis: (1 pt) BIOL%114%

Explain the effects of a semipermeable membrane like the cell membrane on movement by solutes and water. Distinguish diffusion and osmosis. 2. Explain the effects of a semipermeable membrane like the cell membrane on movement by essay Only Nursing Papers.