Question

diffusion and osmosis worksheet

1. how are the molecules moving in the examples below? write osmosis or diffusion.

a. the student sitting next to you just came from gym class and forgot to shower and you can tell. diffusion
b. after sitting in the bathtub for hours, your fingers start to look like prunes. osmosis
c. the girl sitting two rows ahead of you put on too much perfume this morning. diffusion
d. one way to get rid of slugs in your garden is to sprinkle salt on them, so they shrivel up. osmosis
e. yum! something smells good. the neighbors are cooking on the grill! diffusion
f. gargling with salt water when you have a sore throat causes your swollen throat cells to shrink and feel better. osmosis
g. oxygen molecules move from the air sacs in the lungs across the cell membranes into the blood. diffusion

1. use arrows to indicate the direction of diffusion in each case below:
2. for each of the situations below use an arrow to indicate the net movement of sugar into or out of the cell. (assume that the sugar molecules can pass through the cell membrane in each case.)
3. diffusion always causes particles to move from a region of low concentration to a region of high concentration.
4. does a cell use energy when molecules diffuse in or out of the cell? why?

Explanation:

Step1: Define diffusion and osmosis

Diffusion is the movement of molecules from high - to low - concentration. Osmosis is the movement of water across a semi - permeable membrane from an area of low solute concentration to high solute concentration.

Step2: Answer question 1

a. The smell of the unshowered student spreads by diffusion.
b. Fingers getting pruny is due to water movement (osmosis) as water moves into the skin cells.
c. Perfume smell spreading is diffusion.
d. Slugs shriveling is due to water leaving them (osmosis) as salt creates a high - solute environment.
e. Smell of grilling food spreading is diffusion.
f. Gargling with salt water causes water to leave swollen throat cells (osmosis).
g. Oxygen movement from lungs to blood is diffusion.

Step3: Answer question 2

In A, arrows should point from outside (higher concentration) to inside (lower concentration). In B, arrows should point from inside (higher concentration) to outside (lower concentration).

Step4: Answer question 3

For 1% sugar cell in 5% sugar, arrow points out (sugar moves out). For 3% sugar cell in 1% sugar, arrow points in (sugar moves in). For 1% sugar cell in 1% sugar, no net movement (equilibrium).

Step5: Answer question 4

Diffusion causes particles to move from a region of high concentration to a region of low concentration. The given answers in the worksheet for this question are incorrect.

Step6: Answer question 5

No, a cell does not use energy when molecules diffuse in or out of the cell. Diffusion is a passive process that occurs due to the random motion of molecules and the concentration gradient.

Answer:

1. a. Diffusion

b. Osmosis
c. Diffusion
d. Osmosis
e. Diffusion
f. Osmosis
g. Diffusion

1. In A, arrows from outside to inside. In B, arrows from inside to outside.
2. First cell: arrow out. Second cell: arrow in. Third cell: no net movement.
3. high; low
4. No; Diffusion is a passive process.