Search results
Results from the WOW.Com Content Network
A plant cell wall was first observed and named (simply as a "wall") by Robert Hooke in 1665. [3] However, "the dead excrusion product of the living protoplast" was forgotten, for almost three centuries, being the subject of scientific interest mainly as a resource for industrial processing or in relation to animal or human health.
The structural role of phlorotannins in brown algal cell wall is a primary role of these polyphenolic compounds. [7] [13] This primary role may however not be the main role of the phlorotannins, since studies show they are more abundant in cytoplasm or in the exuded form than in cell wall. [28]
Red algal morphology is diverse ranging from unicellular forms to complex parenchymatous and non- parenchymatous thallus. [44] Red algae have double cell walls. [45] The outer layers contain the polysaccharides agarose and agaropectin that can be extracted from the cell walls as agar by boiling. [45] The internal walls are mostly cellulose. [45]
They can either be loosely attached to the cell wall or excreted into the environment. [8] [9] Many microalgae, especially a variety of red algae and cyanobacteria, are producers of structurally diverse exopolysaccharides. Additionally, exopolysaccharides are involved in cell-to-cell interactions, adhesion, and biofilm formation. [10] [11]
Desmodesmus species usually produce colonies of more than one cell, but single cells (unicells) may be found as well. [5] These single cells may be confused with Lagerheimia, a genus of single-celled algae. [6] The cell wall of Desmodesmus consists of an outer layer with a net-like structure, with "rosettes" of tubes underneath. [7]
Chlamydomonas reinhardtii is a single-cell green alga about 10 micrometres in diameter that swims with two flagella.It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an eyespot apparatus that senses light.
The structure of these algae is unicellular, and lacks flagella.Although most desmid species are unicellular, some genera form chains of cells, called filaments. A few genera form non-filamentous colonies, with individual cells connected by threads or remnants of parent cell walls.
The chlorophyte and charophyte green algae and the embryophytes or land plants form a clade called the green plants or Viridiplantae, that is united among other things by the absence of phycobilins, the presence of chlorophyll a and chlorophyll b, cellulose in the cell wall and the use of starch, stored in the plastids, as a storage polysaccharide.