frustule
Sign in to savethumb|upright=1.3|Scanning electron micrographs of frustules from some algae species - scale bar = 10 micrometres in a, c and d and 20 micrometres in b A frustule is the hard and porous cell wall or external layer of diatoms. The frustule is composed almost purely of silica, made from silicic acid, and is coated with a layer of organic substance, which was referred to in the early literature on diatoms as pectin, a fiber most commonly found in cell walls of plants. This layer is actually composed of several types of polysaccharides.
Article
7 sectionsContents
- Thecae
- Pseudoseptum
- Diatom skeletons and their uses
- Frustule formation
- References
- External links
- Regarding the Super formula
thumb|upright=1.3|Scanning electron micrographs of frustules from some algae species - scale bar = 10 micrometres in a, c and d and 20 micrometres in b A frustule is the hard and porous cell wall or external layer of diatoms. The frustule is composed almost purely of silica, made from silicic acid, and is coated with a layer of organic substance, which was referred to in the early literature on diatoms as pectin, a fiber most commonly found in cell walls of plants. This layer is actually composed of several types of polysaccharides.
The frustule's structure is usually composed of two overlapping sections known as thecae (or less formally as valves). The joint between the two thecae is supported by bands of silica (girdle bands) that hold them together. This overlapping allows for some internal expansion room and is essential during the reproduction process. The frustule also contains many pores called areolae and slits that provide the diatom access to the external environment for processes such as waste removal and mucilage secretion.