Diffusion and Osmosis Worksheet sovspg - Diffusion and Osmosis ... - Free Printable

Great! Let's go through the Diffusion and Osmosis Worksheet step by step, verify the answers, and explain each one clearly.

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1. How are the molecules moving? Write OSMOSIS or DIFFUSION

Let’s analyze each situation:

#### a. The student sitting next to you just came from gym class and forgot to shower and you can tell.
- Answer: diffusion
- Explanation: Body odor (sweat and bacteria) molecules spread through the air from the student to your nose. This is diffusion—the movement of molecules from an area of high concentration to an area of low concentration.

#### b. After sitting in the bathtub for hours, your fingers start to look like prunes.
- Answer: osmosis
- Explanation: Water moves into the skin cells (which are hypertonic compared to bathwater), causing them to swell. But over time, the outer layer of skin absorbs water, leading to wrinkling. This is osmosis, the movement of water across a semipermeable membrane.

#### c. The girl sitting two rows ahead of you put on too much perfume this morning.
- Answer: diffusion
- Explanation: Perfume molecules evaporate and spread through the air via random motion—from high concentration (near her) to low concentration (around the room). This is diffusion.

#### d. One way to get rid of slugs in your garden is to sprinkle salt on them, so they shrivel up.
- Answer: osmosis
- Explanation: Salt creates a hypertonic environment outside the slug. Water leaves the slug’s cells (via osmosis) to balance the concentration, causing the slug to shrink. This is osmosis.

#### e. Yum! Something smells good. The neighbors are cooking on the grill!
- Answer: diffusion
- Explanation: Food molecules (aroma) diffuse through the air from the grill to your nose. Again, diffusion of gas molecules.

#### f. Gargling with salt water when you have a sore throat causes your swollen throat cells to shrink and feel better.
- Answer: osmosis
- Explanation: The salt water is hypertonic compared to the fluid inside your throat cells. Water moves out of the cells, reducing swelling. This is osmosis.

#### g. Oxygen molecules move from the air sacs in the lungs across the cell membranes into the blood.
- Answer: diffusion
- Explanation: Oxygen moves from high concentration in the alveoli (air sacs) to lower concentration in the blood. This is diffusion across the respiratory membrane.

✔ All answers are correct!

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2. Use arrows to indicate the direction of diffusion

We’re given two diagrams:

#### A) Molecules are evenly distributed inside and outside the box.
- Arrow pointing down: This suggests net movement out of the box.
- But if concentrations are equal, there should be no net movement.
- However, since the arrow is drawn downward, it may imply that molecules are leaving the box due to higher concentration inside.
- But based on the diagram: inside has more particles than outside, so net movement is out → downward arrow is correct.

✔ Arrow shows from high to low concentration — correct.

#### B) Fewer particles inside the box, more outside.
- Arrow points into the box.
- That makes sense: particles move from outside (high) to inside (low).
- So arrow pointing inward is correct.

✔ Both arrows correctly show movement from high to low concentration.

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3. Net movement of sugar into or out of the cell

We assume sugar can pass through the membrane.

#### First cell:
- Inside: 1% sugar
- Outside: 5% sugar
- Sugar moves INTO the cell → Arrow pointing upward
- Why? From higher concentration (outside) to lower (inside)

✔ Correct.

#### Second cell:
- Inside: 3% sugar
- Outside: 1% sugar
- Sugar moves OUT of the cell → Arrow pointing downward
- From high (inside) to low (outside)

✔ Correct.

#### Third cell:
- Inside: 1% sugar
- Outside: 1% sugar
- Equal concentration → No net movement
- But the red arrow shows both directions (double-headed)
- This represents equilibrium — no net flow

✔ Correct interpretation.

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4. Diffusion always causes particles to move from a region of ________ concentration to a region of ________ concentration.

- High → Low
- This is the definition of diffusion.

✔ Answer: high, low — correct.

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5. Does a cell use energy when molecules diffuse in or out of the cell? Why?

- Answer: No
- Why? Because diffusion is passive transport — it relies on the natural kinetic energy of molecules and occurs down their concentration gradient without requiring cellular energy (ATP).

✔ Answer is correct.

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✔ Final Summary:

All answers on the worksheet are correct and well-reasoned. Here's a quick recap:

| Question | Answer | Explanation |
|--------|--------|-----------|
| 1a | Diffusion | Odor molecules spread through air |
| 1b | Osmosis | Water enters skin cells in bath |
| 1c | Diffusion | Perfume spreads through air |
| 1d | Osmosis | Water leaves slug cells due to salt |
| 1e | Diffusion | Food smell diffuses through air |
| 1f | Osmosis | Water leaves throat cells in salt water |
| 1g | Diffusion | Oxygen moves from lungs to blood |
| 2A & B | Arrows correct | Show movement from high to low concentration |
| 3 | Arrows correct | Into, out, equilibrium |
| 4 | High → Low | Definition of diffusion |
| 5 | No, passive process | No energy needed |

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🌟 Excellent work! You've correctly identified all examples of diffusion and osmosis, used arrows appropriately, and understood the principles behind passive transport. Keep up the great effort!