AP Biology: Plasma Membrane 3D Model Project

"The Mosaic of Life" - Construct a 3D model using everyday household items

Project Overview

Objective

To construct a physically accurate and creatively designed 3D model of the plasma membrane (fluid mosaic model) using everyday household items. This project will help you visualize the structure and understand the functions of the various components that make up the cell's critical boundary.

Theme: "The Mosaic of Life"

Due Date: November 28, 2025

Part 1: Project Instructions

Step 1: Understand the Components

Your model must include accurate representations of the following key components:

Step 2: Gather Your Household Materials

Be creative! Here are some suggestions:

Base/Frame

  • Shoebox lid
  • Cardboard
  • Styrofoam sheet
  • Baking tray

Phospholipids

  • Heads: Play-Doh, clay, marshmallows, beads
  • Tails: Pipe cleaners, straws, Twizzlers

Proteins

  • Channel Protein: Straw, penne pasta, paper tube
  • Other Proteins: Different colored clay, folded paper, Lego blocks

Other Components

  • Carbohydrate Chains: Pipe cleaners, frayed string, yarn
  • Cholesterol: Toothpicks with clay, T-shaped pasta
  • Adhesive: Glue, tape, hot glue gun

Step 3: Construct Your Model

  1. Create the Base: Choose your base (e.g., a piece of cardboard). This represents the extracellular space above and the cytoplasm below.
  2. Build the Phospholipids: Assemble individual phospholipids. For example, attach two pipe cleaner "tails" to a marshmallow "head." You will need many of these.
  3. Form the Bilayer:
    • Arrange your phospholipids in TWO LAYERS (a bilayer).
    • The hydrophilic heads should face outward toward the base (extracellular space) and inward toward the base (cytoplasm).
    • The hydrophobic tails should face each other, in the middle of the bilayer.
    • Do not make the bilayer perfectly uniform; the fluid mosaic model shows it as flexible and fluid.
  4. Embed the Proteins:
    • Integral Proteins (like transport proteins) must span the entire membrane, from one side to the other.
    • Peripheral Proteins should be attached only to the surface of the phospholipid heads.
    • Use different shapes/colors for channel vs. carrier proteins.
  5. Add the Details:
    • Attach carbohydrate chains to some proteins (making them glycoproteins) and to some phospholipid heads (making them glycolipids). These should only be on the extracellular side.
    • Tuck cholesterol molecules between the phospholipids in both layers, primarily near the tails.
  6. Label Your Model: Create small flags or tags using toothpicks and paper. Clearly label every single component. This is crucial for your grade!

Step 4: Present and Explain

Be prepared to briefly explain your model to the class or your teacher, describing the function of at least three of the components you included.

Part 2: Grading Rubric (Total: 30 Points)

Category Exemplary (5-4 pts) Proficient (3-2 pts) Developing (1-0 pts)
Accuracy of Structure & Components (10 pts) Model includes a clearly identifiable phospholipid bilayer and all 6 required components are present and correctly positioned. Model includes a phospholipid bilayer but is missing 1-2 required components, OR 1-2 components are not accurately represented/placed. Model is missing 3 or more required components, OR the fundamental bilayer structure is incorrect.
3D Representation & Creativity (10 pts) Model is fully 3-dimensional, sturdy, and creatively constructed. Materials are used in an innovative and highly effective way. Model is primarily 3D but may have flat elements. Creativity and material choice are adequate but not inventive. Model is flat or lacks a 3D structure. Construction appears rushed with little creativity in material use.
Labels & Identification (5 pts) All components are clearly and correctly labeled with easy-to-read tags. Labels are permanent and neat. Most components are labeled, but some are missing, incorrect, or messy. Labels are missing, incorrect, or illegible for the majority of the components.
Function & Explanation (5 pts) Student can clearly and correctly explain the function of at least 3 key components, demonstrating a strong link between structure and function. Student can explain the function of 1-2 components, but explanations may be vague or contain minor inaccuracies. Student cannot correctly explain the function of the components or refuses to present.
Total Score: /30

Teacher Comments:

Tips for Success

Good luck and have fun creating your "Mosaic of Life"!