heterocyst A specialized cell found in nitrogen-fixing cyanobacteria. Heterocysts are enlarged cells with thick cell walls and they lack chlorophyll, giving them a colourless appearance. They are the site of nitrogen fixation, for which they produce the enzyme nitrogenase. The lack of photosynthetic activity (which would produce oxygen), together with the thick cell wall, are thought to maintain the anoxic conditions in heterocysts that are essential for the activity of nitrogenase. Heterocysts are connected by plasmodesmata to surrounding cells, on which they depend for nutrients.
More From encyclopedia.com
Cells , Cells Plants are multicellular organisms composed of millions of plant cells. Although individual cells may differ greatly from each other in mature… Adherens Junction , adherens junction A cell junction that is commonly observed in epithelial (see EPITHELIUM) cells (e.g. those lining the intestine and those in cardia… Plasma Membrane , Plasma membranes envelop all plant and animal cells and all single-celled eukaryotes and prokaryotes , separating them from their environments. Struc… Cell , Cell The cell is the basic unit of a living organism. In multicellular organisms (organisms with more than one cell), a collection of cells that work… Schwann Cell , Schwann cell (neurilemma cell) A cell that forms the myelin sheath of a nerve fibre. Each cell is responsible for a single length of the fibre (calle… T Cell , T cell T cell (T lymphocyte) Any of a population of lymphocytes that are the principal agents of cell-mediated immunity. T cells are derived from the…
About this article
All Sources -
Updated About encyclopedia.com content Print Topic
You Might Also Like