bacteria

Vitamin

...organisms' requirements become. For example, some bacteria need adenine . Pyrroloquinoline quinone (PQQ) was reported as a vitamin for mice in 2003 . In general, plants can synthesize all the organic substances they need and therefore, do not require any vitamins. See also Pharmacology Vi...

Virus

...s used to describe those infecting prokaryotes ( bacteria and bacteria-like organisms). Typically these par...lism. The rapid growth and small genome size of bacteria make them excellent tools for experiments in biology. Bacterial viruses have also further simplifie...

Virology

...also molecular biology phage , the virus of bacteria / prokaryotes viral plaque Important publications in virology Virus classification...

Vaccine

...s may be living, weakened strains of viruses or bacteria which intentionally give rise to inapparent-to-tr...evelopment and also in use: Conjugate - certain bacteria have outer coats that inexperienced immune systems don't recognize. By linking these unknown outer ...

Systems biology

...he complexity of even a "simple" organism like the bacteria Escherichia coli means that this goal is likely a long ways away. Some scientists have called systems biology " systeomics " or " interactomics ", in analogy with other -omics such as genomics and proteomics , but these terms are not used...

Species

... Quote: "...gene-swapping was common among ancient bacteria early in evolution..."...

Speciation

...anagenesis . Among simpler forms of life, such as bacteria , single mutations can cause drastic changes (called "saltation") that result in speciation in a very short time. Speciation is also related to a process known as adaptive radiation . Speciation mechanisms Ernst Mayr proposed a speciation m...

Shigella

...-negative , nonmotile, nonsporeforming rod-shaped bacteria . They are pathogens of humans and other primates, causing shigellosis . Depending on age and condition of the host, as few as 10 cells can be enough to cause an infection. The disease is caused when virulent Shigella organisms attach to, and ...

Signal transduction

...t a small stimulus elicits a large response. In bacteria and other one-cell organisms , the variety of signal transduction processes of which the cell is capable influences how many ways it can react and respond to its environment. In a less direct way the same is true of animals and plants . Sensing...

Secondary metabolite

...etter known as a source of secondary metabolites, bacteria , fungi and many marine organisms (sponges, tunicates, corals, snails) are very interesting sources, too. Secondary metabolites can be classified by their chemical structure or physical properties into one or more of the following groups: alkal...

Blood type

...proteins , and that antibodies created against the bacteria will react to ABO-incompatible blood cells. Apart from on red blood cells, the ABO antigen is also expressed on the glycoprotein von Willebrand factor (vWF), which participates in hemostasis (control of bleeding). In fact, blood type O predisp...

Restriction enzyme

...herefore are believed to be a mechanism evolved by bacteria to resist viral attack and to help in the removal ...aming Restriction enzymes are named based on the bacteria in which they are isolated in the following manner: E Escherichia (genus) co ...

Proton pump

... to establish an electrochemical potential . In bacteria , mitochondria and other ATP-producing organelles, reducing equivalents provided by electron transfer or photosynthesis power this translocation of protons. For example, the translocation of protons by cytochrome c oxidase is powered by redu...

Prokaryote

... among groups of organisms. Most prokaryotes are bacteria , and the two terms are often treated as synonyms. However, Woese has proposed dividing prokaryotes into the Bacteria and Archaea (originally Eubacteria and Archaebacteria) because of the significant genetic differences between the two. This co...

Prion

...ior to Prusiner's insight, all known pathogens ( bacteria , viruses , etc.) contained nucleic acids that are necessary for reproduction. The prion hypothesis was developed to explain why the mysterious infectious agent causing Creutzfeldt-Jakob disease resisted ultraviolet radiation (which breaks down...

Primary nutritional groups

...eria are photolithoautotrophic, purple non-sulfur bacteria are photoorganoheterotrophic. Some bacteria are limited to only one nutritional group, whereas others are facultative and switch from one mode t...

Polysaccharide

...se. Certain animals can digest cellulose, because bacteria possesing the enzyme are present in their gut. Acidic polysaccharides Acidic polysaccharides are a group of polysaccharides that contain carboxyl groups and/or sulfuric ester groups ....

Plasmid

...e chromosomal DNA (Fig. 1). They usually occur in bacteria , sometimes in eukaryotic organisms (e.g., the ... capable of providing antibiotic resistance to the bacteria that harbors them. The plasmids are next inserted into bacteria by a process called transformation...

Cell membrane

...tablishes this separation alone, whereas in yeast, bacteria and plants an additional cell wall forms the outermost boundary, providing primarily mechanical support. The plasma membrane is only about 10 nm thick and may be discerned only faintly with a transmission electron microscope . One of the key rol...

Alga

...und in higher plants. They are distinguished from bacteria and protozoa in that they are photoautotrophic...hey have a prokaryotic cell structure typical of bacteria and conduct photosynthesis directly within the cytoplasm , rather than in specialized organelles. ...

Photosynthesis

...cal process in which plants , algae , and some bacteria harness the energy of light to produce food. Ult...thesis in plants 2 Photosynthesis in algae and bacteria 3 At the molecular level 4 Discovery 5 Factors affecting photosynthesis 6 In Detail ...

Phage

...nsumption) is a small virus that infects only bacteria . Like viruses that infect eukaryotes , phages co...sion . A famous example is the harmless Vibrio bacteria strain, which is turned into Vibrio cholerae by a phage, causing cholera . Phages play an impo...

Polymerase chain reaction

...Polymerase taken from thermophilic (heat-loving) bacteria that grow in geysers at a temperature of over 110C. The DNA-Polymerase taken from these organisms is thermostable (stable at high temperatures) and, when used in PCR, did not break down when the mixture was heated to separate the DNA strands. Sin...

Oswald Avery

...g new genetic characteristics) them. Therefore if bacteria transform when an organic molecule is placed in li... holds genetic information. For the experiment, a bacteria called a Pneumococcus was used. The R strain is harmless, while the S strain causes pneumonia ...

Origin of life

...e originated around the same time or earlier than bacteria , most of which live on the surface including the oceans. It is claimed that discovery of microbial life below the surface of another body in our solar system would lend significant credence to this theory. He also noted that a trickle of food fr...

Organelle

...rganelles probably originated from endosymbiont bacteria : chloroplast mitochondrion Other organelles include: centriole endoplasmic reticulum golgi apparatus lysosome myofibril plastids nucleus peroxisome ribosome vacuole vesicle melanosome Oth...

Nutrition

...gestion system contains a population of a range of bacteria which are essential to digestion, and which are also affected by the food we eat. The previous mechanistic view of food as fuel, and the simplistic notion that protein, carbohydrate etc. were each obtained from one type of food (the meat and two ve...

Muller's ratchet

...xual reproduction. Horizontal gene transfer in bacteria allows a similar situation. Generally, only obligate endosymbionts, mitochondria and chloroplasts are exposed to Muller's ratchet. But even sexually reproducing organisms are exposed to Muller's ratchet in the case of single-copy chromosomes, such a...

Antibiotic resistance

... through mutation or plasmid exchange between bacteria of the same species . If a bacterium carries sev...ibiotic action is an environmental pressure; those bacteria which have a mutation allowing them to survive will live on to reproduce. They will then pass this ...

Mitochondrion

... ancestors of modern mitochondria were independent bacteria that colonized the interior of the ancient precursor of all eukaryotic life. External links Mitochondrion Reconstructed by Electron Tomography See also Endosymbiotic theory Chemiosmotic hypothesis Chloroplast Submitochon...

Mitochondrion

... ancestors of modern mitochondria were independent bacteria that colonized the interior of the ancient precursor of all eukaryotic life. External links Mitochondrion Reconstructed by Electron Tomography See also Endosymbiotic theory Chemiosmotic hypothesis Chloroplast Submitochon...

Microorganism

...crobes have DNA sequences similar to a category of bacteria known as Deinococcus..." BBCNews: 16 January, 2002, Tough bugs point to life on Mars Citat: "...This research demonstrates that certain microbes can thrive in the absence of sunlight by using hydrogen gas..." BBCNews: 17 January, 2002, Alien l...

Microbiology

...een exposed to phage, instead of arising after the bacteria had been exposed to the virus. The extensive ch...netically modified in vitro then inserted into bacteria that are grown in a culture to produce large amounts of protein using genes encoded on a plasmid. ...

Metabolism

...athway , an alternative glycolysis pathway in few bacteria . Pentose phosphate pathway (hexose monophosphate shunt), generation of NADPH from glucose. Protein catabolism , the hydrolysis of proteins into amino acids . Aerobic respiration Electron transfer chain Oxidative phos...

Major histocompatibility complex

...sentation of extracellular pathogens (for example, bacteria that might be infecting a wound or the blood.) Class II molecules interact exclusively with CD4+ T cells (also known as helper T cell lymphocytes or HTLs). The helper T cells then help to trigger an appropriate immune response which may include loc...

Louis Pasteur

...which liquids such as milk were heated to kill all bacteria and molds already present within them. He and Cla... . During this work, a culture of the responsible bacteria had spoiled and failed to induce the disease in some chickens he was infecting with the disease. ...

Lac repressor

...zyme which stops the metabolism of lactose in bacteria as long as glucose is available. When glucose is scarce and lactose is plentiful the lac repressor becomes inactive to permit the conversion of lactose to glucose. Human DNA encodes recipes for making various types of RNA which in turn ma...

Immune system

...e against foreign pathogens (such as viruses , bacteria , parasites ), some poisons , as well as cancer... The humoral immune system , which acts against bacteria and viruses in the body liquids (such as blood ). Its primary means of action are proteins called ...

Photosynthesis

...cal process in which plants , algae , and some bacteria harness the energy of light to produce food. Ult...thesis in plants 2 Photosynthesis in algae and bacteria 3 At the molecular level 4 Discovery 5 Factors affecting photosynthesis 6 In Detail ...

Heterotroph

...s are heterotrophic, as well as fungi and many bacteria . Some parasitic plants have also turned fully or partially heterotrophic, whereas carnivorous plants use their flesh diet to augment their nitrogen supply, but are still autotrophic. See also : Primary nutritional groups...

Hershey-Chase experiment

...organisms.A phage is a small virus that infects bacteria . It consists of a protein coat that encloses th...ed protein infected bacteria. In both experiments, bacteria were separated from the phage coats by blending followed by centrifugation . In the first experimen...

HACEK organism

... is one of a set of slow-growing Gram negative bacteria that form a normal part of the human flora . They are a frequent cause of inflammation of the inner layer of the heart, ( endocarditis ) in children . The name is formed from their initials: H aemophilus aphrophilus and Haemophilus paraphr...

Growth curve

...re 1, see Lac operon for details) the number of bacteria present in a nutrient-containing broth was measur...rent sugars were present, glucose and lactose. The bacteria prefer to consume glucose (Phase I) and only use the lactose (Phase II) after the glucose has been d...

Glycolysis

...d any of a variety of products. For example, the bacteria involved in making yogurt simply reduce the pyruvate to lactic acid , whereas yeast produce ethanol and carbon dioxide . In aerobic organisms , the pyruvate typically enters the citric acid cycle , and the NADH is ultimately oxidized by ...

Genetics

... hereditary molecule that is transmissible between bacteria (see Griffiths experiment ) 1931 Crossing over is the cause of recombination 1941 Edward Lawrie Tatum and George Wells Beadle show that genes code for proteins ; see the original central dogma of genetics 1944 Oswald Theodore Av...

Gene therapy

...ucing human genes to bacterial DNA. The modified bacteria then produce the corresponding protein, which can be harvested and injected in people who cannot produce it naturally. Scientists took the logical step of trying to introduce genes straight into human cells, focusing on diseases caused by single-ge...

Genetic code

..., where CUG codes for Serine. In some species of bacteria and archaea , a few non-standard amino acids are substituted for standard stop codons; UGA can code for selenocysteine and UAG can code for pyrrolysine . There may be other non-standard interpretations that are not known. Despite these variati...

Gene

...s essentially the same for all known life , from bacteria to humans . Through the proteins they encode, ... , injections into a mouse of a deadly strain of a bacteria that had been heat-killed transferred genetic information to a safe strain of the same bacteria, kil...

Fungus

...e first antibiotic known to modern science. Many bacteria have since become resistant to penicillin, but it is still used against Streptococcus and other very dangerous germs. The world's largest organism is a fungus: Armillaria ostoyae , the largest specimen spanning 8.9 square kilometres (2200 acr...

Cell membrane

...tablishes this separation alone, whereas in yeast, bacteria and plants an additional cell wall forms the outermost boundary, providing primarily mechanical support. The plasma membrane is only about 10 nm thick and may be discerned only faintly with a transmission electron microscope . One of the key rol...

Flagellum

...ave evolved from such pores. Different species of bacteria have different numbers and arrangements of flagella. Monotrichous bacteria have a single flagellum. Lophotrichous bacteria have multiple flagella located at the same spot on t...

Fermentation

...e, in pickling the acid produced by the dominant bacteria inhibit the growth of all other microorganisms. Fermentated foods, by region World wide: olives , vinegar , wine , yoghurt Asia India: achar , gundruk , Indian pickles South East Asia : asinan , bai-ming , belacan , burong mang...

Experimental evolution

...pically carried out with microorganisms such as bacteria or viruses . Contents showTocToggle("show"...rtaken. Since the inception of the experiment, the bacteria have grown for more than 20,000 generations. Lenski and colleagues regularly publish updates on the ...

Excretion

...estive system. Feces may contain about one-third bacteria , most of which are harmless, even beneficial while in the gut , but dangerous to others and they may also contain virulent and even deadly pathogens in the form of bacteria, viruses , amoebae , and various parasitic worms . Urine, on the ot...

Eukaryote

...nicellular. In contrast, other organisms such as bacteria lack nuclei and other complex cell structures, and are called prokaryotes . The eukaryotes share a common origin, and are often treated formally as a superkingdom, empire, or domain . The name comes from the Greek eus or true and karyon or n...

Evolution

...data, showing the separation of the three domains bacteria , archaea , and eukaryotes as described initially by Carl Woese . Trees constructed with other genes are generally similar, although they may place some early-branching groups very differently, presumably owing to rapid rRNA evolution. The exact ...

Bacterium

...cribed in the article about prokaryotes , because bacteria are prokaryotes, in contrast to organisms with mor...al links History and taxonomy The first bacteria were observed by Antony van Leeuwenhoek in 1683 using a single-lens microscope of his own design...

Ethyl alcohol

...ving their lipids and is effective against most bacteria and fungi , and many viruses , but is ineffective against bacterial spores . Because of this disinfectant property, alcoholic beverages can be stored for a long time. See also alcohol fuel alcoholic beverages biodiesel denatured al...

Enzyme

...amase : breaks down penicillin , rendering those bacteria that produce beta-lactamase resistant Catalase : converts hydrogen peroxide to oxygen and water Chitinase : breaks down chitin Cholinesterase Chymosin : better known as rennet, contained in the stomachs of many animals and causes milk t...

Endosymbiotic theory

...tulates that the mitochondria evolved from aerobic bacteria (probably proteobacteria , related to the rickett...loroplasts arose via an ancient endosymbiosis of a bacteria is as follows: Both mitochondria and chloroplasts contain DNA , which is fairly different from t...