Question

label the diagrams of cells using the following terms: diffusion, active transport, osmosis, equilibrium. the arrows show the direction of transport. you may use the terms more than once! osmosis practice activity
osmosis is the diffusion of water from an area of high concentration to an area of low concentration. only water moves in osmosis! the diagrams below show the concentration of water and salt inside a cell and the concentration of water and salt surrounding the cell. complete the sentences below comparing the concentration of the water inside the cell and the concentration outside the cell.
a. water will flow ______________ (into the cell, out of the cell, in both directions).
b. the cell will ______________ (shrink, burst, stay the same).
a. water will flow ______________ (into the cell, out of the cell, in both directions).
b. the cell will ______________ (shrink, stay the same).
a. water will flow ______________ (into the cell, out of the cell, in both directions).
b. the cell will ______________ (shrink, stay the same).

Explanation:

1. For the first set of cell - transport diagrams:

• When CO₂ moves from high to low levels, it is diffusion as it is the movement of a substance (gas in this case) from an area of high concentration to low concentration without the use of energy.
• When water moves from an area of high water molecule concentration to low water molecule concentration (e.g., 8 H₂O to 2 H₂O), it is osmosis since osmosis is the diffusion of water across a semi - permeable membrane.
• When glucose moves from an area of high concentration to low concentration (25 glucose molecules to 5 glucose molecules), it is diffusion if no energy is used, but if energy is required it could be active transport. Without information about energy use, we assume diffusion for now.
• When water moves from 2 H₂O to 8 H₂O, it is osmosis. The diagram with an arrow towards low protein levels is not clear in terms of what is moving, but if it is a substance moving from high to low concentration without energy, it could be diffusion. When there are equal numbers of water molecules on both sides (10 H₂O to 10 H₂O), it is equilibrium as there is no net movement.

1. For the osmosis practice activity:

• In the first case where the cell has 95% H₂O and the outside has 5% H₂O, water will flow into the cell because water moves from an area of high water concentration (inside the cell) to an area of low water concentration (outside the cell). The cell will burst as too much water enters.
• In the second case where both inside and outside have 95% H₂O and 5% NaCl, there is an equal concentration of water inside and outside, so water will flow in both directions and the cell will stay the same.
• In the third case where the cell has 5% H₂O and the outside has 95% H₂O, water will flow out of the cell as water moves from high water concentration (outside) to low water concentration (inside), and the cell will shrink.

Answer:

Cell - transport diagrams:

1. High CO₂ to low CO₂: Diffusion
2. 8 H₂O to 2 H₂O: Osmosis
3. 25 glucose to 5 glucose: Diffusion
4. 2 H₂O to 8 H₂O: Osmosis
5. Arrow towards low protein levels (assuming no energy use): Diffusion
6. 10 H₂O to 10 H₂O: Equilibrium

Osmosis practice activity:

1. a. into the cell

b. burst

1. a. in both directions

b. stay the same

1. a. out of the cell

b. shrink