Question

chapter 4: a tour of the cell

1. one function of lysosomes is intracellular digestion of particles engulfed by phagocytosis. describe this process of digestion.
2. there are many types of vacuoles. briefly describe each type of vacuole below.

food vacuoles:
contractile vacuoles:
central vacuoles in plants:

Explanation:

1. Phagocytosis forms a phagosome. Lysosome fuses with it, releasing digestive enzymes to break - down engulfed particles.
2. Food vacuoles: Formed by phagocytosis, store and digest food. Contractile vacuoles: In single - celled organisms, expel excess water to maintain osmotic balance. Central vacuoles in plants: Store water, ions, nutrients, waste products, and help maintain cell turgor and shape.

Answer:

1. During phagocytosis, a cell engulfs a particle, forming a phagosome. A lysosome then fuses with the phagosome. The lysosome contains digestive enzymes which are released into the phagosome. These enzymes break down the engulfed particle into smaller, usable components.
2. Food vacuoles: They are formed when a cell engulfs food particles through phagocytosis. They store the ingested food and digestive enzymes act on the food to break it down for the cell's use.

Contractile vacuoles: Found mainly in single - celled organisms and some simple multicellular organisms. They collect and expel excess water from the cell, helping to maintain osmotic balance.
Central vacuoles in plants: They are large, fluid - filled organelles. They store water, ions, nutrients, and waste products. They also play a role in maintaining cell turgor pressure, which helps keep plant cells rigid and contributes to the plant's overall shape and support.