Handout - Cell Transport Review Worksheet - Name Cell Transport ... - Free Printable

Let's solve each part of the Cell Transport Review Worksheet step by step and explain the reasoning behind each answer.

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Part 1: Complete the table by checking (✓) the correct column for each statement

| Statement | Isotonic solution | Hypotonic solution | Hypertonic solution |
|----------------------------------|-------------------|--------------------|---------------------|
| Causes a cell to swell | | ✓ | |
| Doesn't change the shape of a cell | ✓ | | |
| Causes osmosis | ✓ | ✓ | ✓ |
| Causes a cell to shrink | | | ✓ |

#### ✔ Explanation:

- Isotonic solution: Equal solute concentration inside and outside the cell → no net movement of water → no change in cell shape.
- Hypotonic solution: Lower solute concentration outside than inside → water enters the cell → cell swells (may burst in animal cells).
- Hypertonic solution: Higher solute concentration outside → water leaves the cell → cell shrinks (plasmolysis in plant cells, crenation in animal cells).
- Osmosis occurs in all three types because it’s the movement of water across a membrane due to concentration differences — but only net movement happens in hypotonic and hypertonic solutions. In isotonic, equilibrium is reached quickly, so there is no net movement, but osmosis still occurs momentarily until balance is achieved.

> So, osmosis happens in all three situations — just not with net effect in isotonic.

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Part 2: Match the term with its correct description

We are given:
- A. osmosis
- B. exocytosis
- C. active transport
- D. endocytosis
- E. facilitated diffusion
- F. passive transport
- G. diffusion
- H. energy

Now match each description:

| Answer | Description | Correct Term |
|--------|-------------|--------------|
| 1 | Is used during active transport but not passive transport | H. energy |
| 2 | Process by which a cell takes in material by forming a vesicle around it | D. endocytosis |
| 3 | Particle movement from an area of higher concentration to an area of lower concentration | G. diffusion |
| 4 | Process by which a cell expels wastes from a vesicle | B. exocytosis |
| 5 | Particle movement from an area of higher concentration to an area of lower concentration using a transport protein | E. facilitated diffusion |
| 6 | The diffusion of water through a cell membrane | A. osmosis |
| 7 | When energy is required to move materials through a cell membrane | C. active transport |
| 8 | When energy is NOT required to move materials through a cell membrane | F. passive transport |

✔ Explanation:
- Energy (H) is required only in active transport, not in passive.
- Endocytosis (D) brings in large molecules via vesicles.
- Exocytosis (B) releases substances out via vesicles.
- Diffusion (G) is general movement down concentration gradient.
- Facilitated diffusion (E) uses proteins but no energy.
- Osmosis (A) = diffusion of water.
- Active transport (C) requires energy.
- Passive transport (F) includes diffusion, osmosis, facilitated diffusion — all without energy.

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Part 3: Label the diagrams

Each diagram shows movement of molecules with arrows indicating direction. We need to label each using: diffusion, active transport, osmosis, equilibrium.

#### Diagram 1:
```
High CO₂ levels
↓
Low CO₂ levels
```
➡️ Answer: Diffusion

- CO₂ moves from high to low concentration → diffusion (no energy needed, simple gas movement).

#### Diagram 2:
```
8 H₂O molecules → 2 H₂O molecules
```
(Inside → Outside)
➡️ Answer: Osmosis

- Water moving from high concentration (inside) to low (outside) → osmosis.

#### Diagram 3:
```
25 glucose molecules → 5 glucose molecules
```
(Inside → Outside)
➡️ Answer: Diffusion

- Glucose moving from high to low concentration → diffusion (assuming no carrier involvement shown). But wait — glucose typically needs carriers, but since no protein mentioned and it's going down gradient, this is facilitated diffusion, but we're limited to the terms listed.

Since "facilitated diffusion" isn't among the allowed labels, and the movement is down the gradient, it's best labeled as diffusion (broadly). However, if only diffusion, active transport, osmosis, or equilibrium are allowed, then diffusion is acceptable here.

But note: Glucose usually doesn’t diffuse freely; it uses facilitated diffusion, but again, we’re restricted to the provided terms.

So: Diffusion

Wait — let's reconsider: If glucose is moving from high to low concentration, it's passive, so not active transport. It’s not osmosis (only water). So best choice: Diffusion.

✔ Answer: Diffusion

#### Diagram 4:
```
2 H₂O molecules → 8 H₂O molecules
```
(Outside → Inside)
➡️ Answer: Osmosis

- Water moving into cell from low to high concentration? Wait: inside has more water (8), outside has less (2). So water is moving into the cell from outside to inside → from low to high? No!

Wait: Water moves from high to low concentration.

But here: Outside has 2 H₂O, Inside has 8 H₂O → that means higher concentration of water inside → water should move out?

But arrow shows from outside to inside → against concentration gradient?

That would be impossible without energy.

Wait — actually, concentration of water is inversely related to solute concentration.

But here, number of molecules may indicate water concentration.

So:
- Outside: 2 H₂O → low water concentration
- Inside: 8 H₂O → high water concentration

→ Water moves from high to low → from inside to outside.

But arrow shows from outside to inside → wrong direction?

Wait — look at arrow: From 2 H₂O → 8 H₂O, meaning into the cell.

So water moving into the cell → from low concentration (outside) to high concentration (inside) → against gradient?

No — that can't happen passively.

But maybe the numbers represent amounts, not concentrations.

Actually, in such diagrams, the number of molecules represents relative concentration.

So:
- If outside has 2 H₂O, inside has 8 H₂O, then water concentration is higher inside → water should move out.

But arrow points in → opposite → this suggests active transport?

But water doesn’t undergo active transport.

Alternatively, perhaps the diagram is showing net movement after some process?

Wait — maybe it's equilibrium?

But no, the numbers are unequal.

Wait — let’s re-read: "The arrows show the direction of transport."

So if water is moving from outside (2) to inside (8), that means water is entering.

But why? Because the inside has more water, so lower solute concentration?

Yes — if inside has more water, then less solute, so hypotonic inside → water will enter → osmosis.

But osmosis is passive, and water moves from high water concentration to low.

So if outside has 2 H₂O, inside has 8 H₂O, then water concentration is higher inside → water should move out.

But arrow shows in → contradiction.

Unless the numbers are not representing concentration.

Wait — perhaps the numbers are just examples, and the arrow indicates net movement.

But in reality, water moves from high concentration to low.

So if outside has fewer water molecules, then water concentration is lower outside, so water moves into cell → yes.

So even though inside has more water molecules, if outside has less, then water moves in → osmosis.

So yes, osmosis is correct.

✔ Answer: Osmosis

But wait — osmosis is the movement of water across a membrane.

Here, water is moving from outside (fewer molecules) to inside (more molecules) → into cell → osmosis.

So even though the inside already has more, the movement is into the cell → osmosis.

Yes.

But now check: Equilibrium? Only if equal on both sides.

Not yet.

So: Osmosis

#### Diagram 5:
```
High protein levels → Low protein levels
```
(Inside → Outside)
➡️ Answer: Active transport

- Proteins are large molecules, and they are moving from high to low concentration? Wait — from high to low → down gradient → could be passive.

But proteins don’t diffuse easily — they use exocytosis or vesicles.

But the term exocytosis is not among the allowed labels.

Allowed: diffusion, active transport, osmosis, equilibrium

- Not osmosis (not water)
- Not diffusion (large molecule, likely needs energy)
- But moving from high to low → passive?

But proteins are usually moved out via exocytosis, which is active.

Even though it’s going down concentration gradient, exocytosis requires energy.

So active transport is the best fit.

✔ Answer: Active transport

Note: While exocytosis is technically involved, "active transport" is the broader category that includes vesicular transport when energy is used.

So yes, active transport.

#### Diagram 6:
```
10 H₂O molecules ↔ 10 H₂O molecules
```
(Both sides have same number, bidirectional arrows)
➡️ Answer: Equilibrium

- Equal water molecules on both sides → no net movement → equilibrium

✔ Answer: Equilibrium

---

✔ Final Answers:

#### Part 1 Table:

| Statement | Isotonic solution | Hypotonic solution | Hypertonic solution |
|----------------------------------|-------------------|--------------------|---------------------|
| Causes a cell to swell | | ✓ | |
| Doesn't change the shape of a cell | ✓ | | |
| Causes osmosis | ✓ | ✓ | ✓ |
| Causes a cell to shrink | | | ✓ |

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#### Part 2 Matching:

| # | Answer |
|----|--------|
| 1 | H. energy |
| 2 | D. endocytosis |
| 3 | G. diffusion |
| 4 | B. exocytosis |
| 5 | E. facilitated diffusion |
| 6 | A. osmosis |
| 7 | C. active transport |
| 8 | F. passive transport |

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#### Part 3 Diagram Labels:

1. CO₂: Diffusion
2. 8 H₂O → 2 H₂O: Osmosis
3. 25 glucose → 5 glucose: Diffusion
4. 2 H₂O → 8 H₂O: Osmosis
5. High protein → low protein: Active transport
6. 10 H₂O ↔ 10 H₂O: Equilibrium

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✔ Summary of Answers:

Part 1:
- Swell → Hypotonic
- No shape change → Isotonic
- Causes osmosis → All three
- Shrink → Hypertonic

Part 2:
1. H
2. D
3. G
4. B
5. E
6. A
7. C
8. F

Part 3:
1. Diffusion
2. Osmosis
3. Diffusion
4. Osmosis
5. Active transport
6. Equilibrium

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