Label the steps of phagocytosis.

a. ________
b. ________
c. ________
d. ________
e. ________
f. ________

Verified step by step guidance

1. Step 1: Identify the initial recognition and attachment phase where the phagocyte detects and binds to the pathogen or particle. This involves receptors on the phagocyte surface recognizing molecules on the target.
2. Step 2: Describe the engulfment phase where the phagocyte's membrane extends around the particle, forming pseudopods that surround it.
3. Step 3: Explain the formation of the phagosome, a membrane-bound vesicle that encloses the engulfed particle inside the phagocyte.
4. Step 4: Outline the fusion of the phagosome with a lysosome to form a phagolysosome, where digestive enzymes and reactive oxygen species are introduced.
5. Step 5: Detail the digestion and breakdown of the engulfed material inside the phagolysosome, followed by the expulsion of indigestible debris through exocytosis.

Key Concepts

Recognition and Attachment

Phagocytosis begins when phagocytic cells recognize and bind to foreign particles or pathogens using specific receptors. This attachment is crucial for targeting the material to be engulfed and initiating the engulfment process.

Engulfment and Phagosome Formation

After attachment, the cell membrane extends around the particle, engulfing it and enclosing it within a membrane-bound vesicle called a phagosome. This step isolates the particle inside the cell for further processing.

Phagolysosome Formation and Digestion

The phagosome fuses with a lysosome to form a phagolysosome, where digestive enzymes and reactive oxygen species break down the engulfed material. This degradation is essential for destroying pathogens and clearing debris.