Cell Junction ✏ Biology In a Nutshell

Rucete ✏ Biology In a Nutshell

1. What are Cell Junctions?

Cell junctions connect cells together and allow the exchange of materials or signals between them.

2. Types of Cell Junctions

1. Anchoring Junctions

• Function: Provide mechanical stability by linking adjacent cells via protein filaments.
• Structure: Cells do not directly touch but are connected by fine protein filaments.
• Example: Found in tissues that experience stress, such as skin and heart muscle.

 

2. Tight Junctions

• Function: Form a sealed barrier between cells to prevent leakage of materials.
• Structure: Creates a tight, stitched seam between animal cells, completely surrounding the connection point.
• Example: Found in the intestines and blood-brain barrier, preventing passage of harmful substances.

 

3. Communicating Junctions

• Function: Allow chemical and electrical signals or material exchange between adjacent cells.
• Types:
  • Gap Junctions:
    • Found in animal cells.
    • Narrow channels composed of connexin proteins that allow ions and small molecules to pass.
    • Example: Heart and nerve cells for synchronized activity.
  • Plasmodesmata:
    • Found in plant cells.
    • Narrow channels allowing cytoplasmic exchange between cells.
    • Important for nutrient and signal transport in plants

In a nutshell

• Anchoring Junctions = Stability & Strength.
• Tight Junctions = Seals & Barriers.
• Gap Junctions & Plasmodesmata = Communication Channels.