vacuole
Noun
Meaning
A small air cell, or globular space, in the interior of organic cells, either containing air, or a pellucid watery liquid, or some special chemical secretions of the cell protoplasm.
Source: Webster's dictionarySynonyms
Hypernyms
Phrases with the word
Examples
A vacuole is surrounded by a membrane called the tonoplast (word origin: Gk tón(os) + -o-, meaning “stretching”, “tension”, “tone” + comb. form repr.
Another function of a central vacuole is that it pushes all contents of the cell's cytoplasm against the cellular membrane, and thus keeps the chloroplasts closer to light.
For example, when the pH in the cells environment drops, the H + ions surging into the cytosol can be transferred to a vacuole in order to keep the cytosol's pH constant. citation In animals, vacuoles serve in exocytosis and endocytosis processes.
Fungi Vacuoles in fungal cells perform similar functions to those in plants and there can be more than one vacuole per cell.
If high salt concentrations are seen within the vacuole, a high concentration gradient will be established between the vacuole and the cytoplasm, leading to high levels of energy investment to maintain this state.
In plant cells, vacuoles cover anywhere from 30% to 90% of the total cell volume. citation Most mature plant cells contain one large central vacuole encompassed by a membrane called the tonoplast.