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Medlin and co-workers erected a new class, Mediophyceae (which could be re-ranked a subclass if diatoms as a whole are ranked as a class rather than a phylum) for the "polar centric" diatoms, which they consider to be more closely related to the pennate rather than to other centric diatoms, a concept which has been followed or further adapted ...
Since diatoms form an important part of the food of molluscs, tunicates, and fishes, the alimentary tracts of these animals often yield forms that are not easily secured in other ways. Diatoms can be made to emerge by filling a jar with water and mud, wrapping it in black paper and letting direct sunlight fall on the surface of the water.
The only chemical elements that form stable homonuclear diatomic molecules at standard temperature and pressure (STP) (or at typical laboratory conditions of 1 bar and 25 °C) are the gases hydrogen (H 2), nitrogen (N 2), oxygen (O 2), fluorine (F 2), and chlorine (Cl 2), and the liquid bromine (Br 2). [1]
A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.
Molecular symmetry in physics and chemistry describes the symmetry present in molecules and the classification of molecules according to their symmetry. Molecular symmetry is a fundamental concept in the application of quantum mechanics in physics and chemistry, for example, it can be used to predict or explain many of a molecule's properties, such as its dipole moment and its allowed ...
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. [1] [2] This layer is actually composed of several types of polysaccharides. [3]
Diatoms are eukaryotic organisms in the phylum Bacillariophyta. This page contains articles about diatoms and diatomists.. Older classifications used to subdivide diatoms into Centrales and Pennales (with Bacillariophyceae used as a class), whereas more recent ones use a three classes system: Bacillariophyceae, Coscinodiscophyceae and Fragilariophyceae.
In diatoms like Phaeodactylum tricornutum, fucoxanthin is protein-bound along with chlorophyll to form a light harvesting protein complex. [4] Fucoxanthin is the dominant carotenoid, responsible for up to 60% of the energy transfer to chlorophyll a in diatoms [ 5 ] When bound to protein, the absorption spectrum of fucoxanthin expands from 450 ...