Endocytosis, phagocytosis, and pinocytosis | Biology | Khan Academy

TL;DR

Cells can transport large substances through two processes: phagocytosis (cell eating) and pinocytosis (cell drinking).

Transcript

• [Voiceover] We have other videos where we talk about how small molecules, or ions, might be able to go through a cell's membrane in different ways, whether actively or passively, maybe facilitated in some way. What we wanna talk about in this video is how we can do this for larger things. We're gonna focus on here is bulk, bulk transport. Transpo... Read More

Key Insights

• 👻 Phagocytosis is a process where a cell wraps its membrane around large particles, allowing it to engulf and digest them.
• 🎁 Pinocytosis is a process where a cell wraps its membrane around fluid, enabling it to take in dissolved materials.
• 💁 Both phagocytosis and pinocytosis are forms of endocytosis, which is the general term for engulfing substances.
• 😅 The terms "phagocytosis" and "pinocytosis" come from Greek words meaning "to eat" and "to drink," respectively.
• 👨‍🔬 The exact mechanisms of how endocytosis occurs and how cells know what to engulf are still areas of active research.
• 👾 The cytoskeleton may play a role in creating space for engulfment and helping the cell's membrane wrap around the engulfed material.

Questions & Answers

Q: What is phagocytosis?

Phagocytosis is a process by which a cell engulfs large particles like bacteria by wrapping its membrane around them, forming a food vacuole. This allows the cell to take in and process the engulfed material.

Q: What is pinocytosis?

Pinocytosis is a process where a cell engulfs fluid by wrapping its membrane around it, forming a vesicle. This enables the cell to drink in the fluid and take in any dissolved materials present.

Q: What is the difference between phagocytosis and pinocytosis?

While both phagocytosis and pinocytosis involve the engulfing of substances, phagocytosis involves the engulfing of large particles like bacteria, while pinocytosis involves the engulfing of fluid.

Q: What is endocytosis?

Endocytosis is the general term for the process of engulfing substances by cells. Phagocytosis and pinocytosis are both specialized forms of endocytosis, with phagocytosis being a form of cell eating and pinocytosis being a form of cell drinking.

Summary & Key Takeaways

• Phagocytosis is a process where a cell engulfs large particles, such as bacteria, by wrapping its membrane around them and forming a food vacuole.

• Pinocytosis is a process where a cell engulfs fluid by wrapping its membrane around it and forming a vesicle.

• Both phagocytosis and pinocytosis are specialized forms of endocytosis, which is the general term for engulfing in this manner.