SOLUTION: cell membrane coloring worksheet 1 - Studypool - Free Printable

Let's solve the problem step by step.

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Part 1: List 4 functions of the cell or plasma membrane

You've already provided four correct functions. Let's refine and clarify them for accuracy:

a. Help maintain homeostasis
→ The plasma membrane regulates what enters and exits the cell, helping to keep the internal environment stable.

b. Exchange materials like food, water, and wastes
→ It allows essential substances (nutrients, oxygen) to enter and waste products (CO₂, urea) to exit the cell.

c. Water, oxygen, CO₂ can move freely
→ These small, nonpolar molecules can diffuse directly through the lipid bilayer without assistance.

d. It is selectively permeable, allowing certain molecules to pass through
→ This means only specific substances can cross the membrane, either via passive diffusion or active transport.

✔ All four are correct and well-expressed.

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Part 2: Color code and identify each part of the cell membrane

We are given a diagram with labeled parts (A, B, C, E, F, G, I), and we need to match the letters to the correct structures based on their color and name.

Let’s analyze the image description and match accordingly:

#### Given Key:
- a → Phospholipid bilayer (no color)
- b → Integral protein (pink)
- f → Fatty acid tails (orange)
- g → Phosphate heads (yellow)
- c → Peripheral protein (red)
- i → Cholesterol (blue)
- h → Glycoprotein (green)
- e → Glycolipids (purple)

Now, let's look at the diagram and assign the letters:

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Step-by-step identification:

1. Phospholipid bilayer (no color) → Letter A
- This is the entire double-layered structure made of phospholipids.
- In the diagram, A is the large bracket enclosing the whole membrane.
✔ So: a = A

2. Integral protein (pink) → Letter B
- Pink structure that spans the membrane from one side to the other.
- In the diagram, the pink shape is embedded in the membrane and crosses it.
✔ So: b = B

3. Fatty acid tails (orange) → Letter F
- Orange color is shown as the wavy lines inside the bilayer (hydrophobic region).
- The orange section is pointing inward.
✔ So: f = F

4. Phosphate heads (yellow) → Letter G
- Yellow is shown on the outer edges of the bilayer (hydrophilic heads).
- These are the round white circles with yellow coloring.
✔ So: g = G

5. Peripheral protein (red) → Letter C
- Red structure is attached to the surface (outside) of the membrane, not spanning it.
- Located on top of the bilayer.
✔ So: c = C

6. Cholesterol (blue) → Letter I
- Blue structure is inserted between the phospholipids, stabilizing the membrane.
- In the diagram, blue is located within the bilayer.
✔ So: i = I

7. Glycoprotein (green) → Letter H
- Green structure has sugar chains (spikes) extending outward.
- It's a protein with carbohydrates attached, found on the extracellular side.
- In the diagram, green is a small oval with protrusions.
✔ So: h = H

8. Glycolipids (purple) → Letter E
- Purple structure has sugar chains (like glycoproteins but lipids).
- Located on the outer surface of the membrane.
- In the diagram, purple is near the top right with spikes.
✔ So: e = E

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✔ Final Answer Table:

| Letter | Name/Color |
|--------|--------------------------------|
| a | Phospholipid bilayer (no color) → A |
| b | Integral protein (pink) → B |
| f | Fatty acid tails (orange) → F |
| g | Phosphate heads (yellow) → G |
| c | Peripheral protein (red) → C |
| i | Cholesterol (blue) → I |
| h | Glycoprotein (green) → H |
| e | Glycolipids (purple) → E |

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Summary:

- The plasma membrane performs critical roles in homeostasis, material exchange, selective permeability, and cell communication.
- The fluid mosaic model shows that the membrane is composed of:
- Phospholipid bilayer (hydrophilic heads outside, hydrophobic tails inside),
- Proteins (integral and peripheral),
- Cholesterol (stabilizes membrane),
- Carbohydrates (glycoproteins and glycolipids) on the extracellular side.

This structure allows the membrane to be both flexible and selectively permeable.

✔ You’ve correctly colored and labeled all components!