Bacteria Archaea
Bacteria Archaea
Microbiology is the study of “small life” – in other words the study of all living organisms that are too small to be visible with the naked eye and ar usually visible only through a microscope. Such organisms ar referred to as microorganisms or microbes. Microorganisms were first observed over three hundred years agone and it is estimated that only one percent of the species of microorganisms that exist have been studied so far. Microbiology is a broad term that includes bacteriology, virology, mycology, phycology, parasitology, and other branches of biology.
Microorganisms admit bacteria, archaea, viruses, protozoa, protists, microscopic fungi and moulds, yeasts, and microscopic algae. Note that viruses, though not always strictly classed as living organisms, are included. Bacteria are a large group of unicellular prokaryotic microorganisms. A few micrometres in length, bacterium have a wide range of shapes, ranging from spheres to rods and spirals. Archaea ar single-celled microorganisms. Like bacteria, Archaea are prokaryotes and have no cell nucleus or any other organelles within their cells. Generally, archaea and bacterium are quite similar in size and shape however archaea have genes and several metabolic pathways that are more closely related to those of eukaryotes. Viruses are sub-microscopic infectious agents that ar unable to grow or reproduce outside a host cell. Microbiologists debate whether or non viruses ar living organisms. They do not meet all the criteria used in the common definitions of life, however, viruses have genes and evolve by natural selection.
Fungi ar eukaryotic, heterotrophic organisms. The majority grow as multicellular filaments called hyphae forming a mycelium but some fungal species grow as single cells. Fungi that ar mostly unseeable to the naked eye ar classed as microorganisms. Yeasts, moulds and mushrooms ar examples of fungi. Algae include many single-celled organisms that are also considered protozoa, such as Euglena. Blue-green alga are in fact bacteria that obtain their energy through photosynthesis. They ar generally, and more correctly, referred to as cyanobacteria.
Protozoa are mostly single-celled, motile protists that feed by phagocytosis, though there are numerous exceptions. Examples of protozoa include Euglena, Amoeba, Paramecium and Toxoplasma. Protists are a various group of eukaryotic microorganisms. Protists were traditionally subdivided into the one-celled animal-like protozoa, the plant-like protophyta (mostly one-celled algae), and the fungus-like slime molds and water molds. These groups have been replaced by phylogenetic-based classifications but ar still used as informal names for describing the various protists.
Microbiology encompasses both prokaryotic and eukaryotic microorganisms but the majority of microbes are prokaryotes. Prokaryotes ar a group of organisms that do non have a membrane-bound nucleus; they do non own a atomic membrane or nuclear envelope. They have DNA but the DNA is not enclosed in a membrane or envelope. In addition, they do non have other membrane-bound organelles. Most ar unicellular, but a few prokaryotes such as Myxobacteria have multicellular stages in their life cycles. The prokaryotes ar divided into two domains: the bacteria and the archaea. Eukaryotes are defined as possessing a atomic membrane enclosing their nucleus. Many eukaryotic cells also contain other membrane-bound organelles such as mitochondria, chloroplasts and Golgi bodies. Animals, plants, fungi and protists ar eukaryotes.
Image Source: http://images.google.com
Respiration in Archaea and Bacteria: Diversity of Prokaryotic Electron Transport Carriers (Advances in Photosynthesis and Respiration)
Product Description
Respiration in Archaea and Bacteria summarizes the achievements of the past decade in the biochemistry, bioenergetics, structural and molecular biology of respiratory processes in selected groups of prokaryotes. It includes a series of Chapters providing an extensive coverage of the respiratory membrane-bound bacterial redox complexes and enzymes; it also covers evolution of respiration, cytochrome c biogenesis, bacterial haemoglobins, and oxidases as redox sensors.
