D) The active transport of a substance out of a cell to maintain equilibrium. E) The movement of solute molecules from a lower to a higher concentration across a semipermeable membrane. Answer: B, osmosis is specifically the movement of solvent, not a solute or a general substance described in
o Carbon dioxide produced by respiration diffuses out of cells. Osmosis: - Water often moves across boundaries by osmosis. - Osmosis is the diffusion of water from a dilute to a more concentrated solution through a partially permeable membrane that allows the passage of water molecules. - Differences in the concentrations of the solutions inside and outside a cell cause water to move into or out of the cell by osmosis. - If there is a higher solute concentration on one side of a membrane, water will move in that direction.
If sugars weren't dissolved, they couldn't reach cells. -Second, the polarity of water is important in repelling nonpolar compounds. Nonpolar compounds don't dissolve well in water (like how oil, a nonpolar solution, forms "beads" in water). This is important to cell membranes in the body. The shape and function of cell membranes depend on the interaction of polar water with nonpolar membrane molecules.
The small inward sodium leak and outward leak of potassium leak are offset by the sodium potassium pumps._ ___ 5. Discuss how a change in Na+ or K+ conductance would affect the resting membrane potential. ___ _The resting period potential is a potential difference between the inside of the cell and the outside of the cell across the membrane. It depends on the resting permeability of the membrane to ions and on the intracellular and extracellular concentrations of those ions to which the membrane is permeable.__ Activity 2 Receptor Potential 1. Sensory neurons have a resting
The variable that affects osmotic pressure is You correctly answered: a. the concentration of nondiffusing solutes. 4. The net movement of water would be into the cell in a You correctly answered: b. hypotonic solution. page 1 Experiment Results Predict Question: Predict Question 1: What effect do you think increasing the Na+ Cl- concentration will have? Your answer : a. increased osmotic pressure Predict Question 2: What do you think will be the pressure result of the current experimental conditions?
Objective Diffusion is the process that occurs when a certain concentrated volume of material moves to a less concentrated state. Osmosis is the movement of a solvent (as water) through a semipermeable membrane (as of a living cell) into a solution of higher solute concentration that tends to equalize the concentrations of solute on the two sides of the membrane. Terms for water flow are hypertonic (has low water concentration and high salt concentration than cells), Hypotonic (solution that has high water concentration and low salt concentration than cells), and isotonic (solution that has the same water and salt concentration as the cells). In this lab, we examined the water flow across the selectively permeable membrane of potato cells. We measured the net movement of the potato membrane by comparing the weight of a potato cube before and after incubation in 7%, 14%, 21%, 28%, and distilled water.
The null hypothesis for this experiment is that if a solution has a concentration gradient across a barrier, then movement will not occur because molecules are small and/or charged. Materials: * Elodea leaves * Water * Beakers * Pipettes *
Water potential is the concept used to combine the differences in solute concentration and pressure to predict the direction in which water will diffuse through the living plant tissue and states that the net movement of water will always be from an area of higher water potential to and area of lower water potential. Water potential can be confirmed by taking the graph of the data. This data can be used to experimentally determine the value for C (molar concentration of sucrose at equilibrium) in order to determine a value for Ψs (Ψs =solute potential). Variable Table: Variable | Unit | How to Control | Independent- Sucrose Concentration | 100mL with varying Molarities (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1.0M) | Premade solutions by lab tech so should be correct. However, will label test tubes with correct Molarities so no confusion occurs.
Phospholipid bilayers and protein molecules form a semi-permeable boundary around the cell. This is called the cell membrane. Molecules that are small enough, such as water and CO2, can pass in and out of the membranes following the concentration path. In the experiment, dialysis bags will be used as cell membranes, sugar as the solute, and water as the solvent. This experiment is designed to allow us to measure the effect of concentration of sucrose and temperature on osmosis over time.
Osmosis and Diffusion: Introduction: In this experiment the principles of osmosis and diffusion were demonstrated. Osmosis is defined as the diffusion of free water (or other liquids) across a selectively permeable membrane from areas of high concentration to areas of lower concentration. The osmosis experiment used 1%, 20%, 40% sucrose solutions in dialysis tubing placed in water to demonstrate the diffusion of water. Diffusion is defined as the spontaneous movement of a substance down its concentration or electrochemical gradient, from an area of high concentration to an area of low concentration1. In the diffusion experiment, phenolphthalein was added to a beaker full of water.