Vakuooli

Vakuooli, also known as vacuole, is a membrane-bound organelle found in plant cells and fungal cells. In animal cells, vacuoles are generally smaller and more numerous, and may perform various functions. The vacuole is essentially a sac within the cytoplasm.

In plant cells, the central vacuole is a large, prominent organelle that can occupy up to 90% of the cell's volume. It plays a crucial role in maintaining turgor pressure, which supports the plant's structure and helps it stand upright. The central vacuole also stores water, nutrients, ions, pigments, and waste products. It can even contain enzymes that break down cellular debris.

In fungal cells, vacuoles are similar in function to those in plant cells, contributing to storage and waste disposal. They can also be involved in maintaining osmotic balance.

Animal cells may contain smaller vacuoles, sometimes referred to as vesicles, which are involved in transport, storage, and waste removal. For example, phagocytic cells in animals can form food vacuoles to engulf and digest foreign particles. Endosomes and lysosomes are also types of vacuoles with specialized roles in cellular digestion and recycling.

The membrane surrounding a vacuole is called the tonoplast in plant cells. The contents of the vacuole are distinct from the cytoplasm, allowing for the isolation of substances that might be harmful or unnecessary for the main cellular processes. The size and number of vacuoles can vary greatly depending on the cell type and its physiological state.