An elongate structure, either cellular or excreted, which anchors a cell to a surface. The period during the growth cycle of a population in which growth ceases. A mirror image form of a molecule . Both have the same molecular and structural formula but different in their stereo arrangement of molecular positions. Even vitamin D is based on the steroid structure.
Cholesterol is one type of sterols.
Because of its hydrophilic property at the -OH end and hydrophobic at the hydrocarbon side chain, it can be incorporated into the lipid bilayers of the cytoplasmic membrane. However, sterols only exist in the cytoplasmic membranes of eukaryotes while in prokaryotes , virtually all do not have sterol in their membranes except mycoplasmas , a group of cell wall-less bacteria. A hot, sulfur-rich, generally acidic environment, commonly inhabited by hyperthermophilic Archaea . A harmful derivative of oxygen capable of oxidative destruction of cell components. A mutation that restores wild-type phenotype without altering the original mutation, usually arising by mutation in another gene .