Ribosomes comprise a complex macromolecular machine, found within all living cells, that serves as the site of biological protein synthesis. Ribosomes link amino acids together in the order specified by messenger RNA molecules. Ribosomes consist of two major components: the small ribosomal subunits, which read the mRNA, the large subunits, which join amino acids to form a polypeptide chain; each subunit consists of a variety of ribosomal proteins. The ribosomes and associated molecules are known as the translational apparatus; the sequence of DNA, which encodes the sequence of the amino acids in a protein, is copied into a messenger RNA chain. It may be copied many times into RNA chains. Ribosomes can bind to a messenger RNA chain and use its sequence for determining the correct sequence of amino acids for generating a given protein. Amino acids are selected and collected and carried to the ribosome by transfer RNA molecules, which enter one part of the ribosome and bind to the messenger RNA chain.
It is during this binding that the correct translation of nucleic acid sequence to amino acid sequence occurs. For each coding triplet in the messenger RNA there is a distinct transfer RNA that matches and which carries the correct amino acid for that coding triplet; the attached amino acids are linked together by another part of the ribosome. Once the protein is produced, it can fold to produce a specific functional three-dimensional structure although during synthesis some proteins start folding into their correct form. A ribosome is therefore a ribonucleoprotein; each ribosome is divided into two subunits: a smaller subunit which binds to a larger subunit and the mRNA pattern, a larger subunit which binds to the tRNA, the amino acids, the smaller subunit. When a ribosome finishes reading an mRNA molecule, these two subunits split apart. Ribosomes are ribozymes, because the catalytic peptidyl transferase activity that links amino acids together is performed by the ribosomal RNA. Ribosomes are associated with the intracellular membranes that make up the rough endoplasmic reticulum.
Ribosomes from bacteria and eukaryotes in the three-domain system, resemble each other to a remarkable degree, evidence of a common origin. They differ in their size, sequence and the ratio of protein to RNA; the differences in structure allow some antibiotics to kill bacteria by inhibiting their ribosomes, while leaving human ribosomes unaffected. In bacteria and archaea, more than one ribosome may move along a single mRNA chain at one time, each "reading" its sequence and producing a corresponding protein molecule; the mitochondrial ribosomes of eukaryotic cells, are produced from mitochondrial genes, functionally resemble many features of those in bacteria, reflecting the evolutionary origin of mitochondria. Ribosomes were first observed in the mid-1950s by Romanian-American cell biologist George Emil Palade, using an electron microscope, as dense particles or granules; the term "ribosome" was proposed by scientist Richard B. Roberts in the end of 1950s: During the course of the symposium a semantic difficulty became apparent.
To some of the participants, "microsomes" mean the ribonucleoprotein particles of the microsome fraction contaminated by other protein and lipid material. The phrase "microsomal particles" does not seem adequate, "ribonucleoprotein particles of the microsome fraction" is much too awkward. During the meeting, the word "ribosome" was suggested, which has a satisfactory name and a pleasant sound; the present confusion would be eliminated if "ribosome" were adopted to designate ribonucleoprotein particles in sizes ranging from 35 to 100S. Albert Claude, Christian de Duve, George Emil Palade were jointly awarded the Nobel Prize in Physiology or Medicine, in 1974, for the discovery of the ribosome; the Nobel Prize in Chemistry 2009 was awarded to Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath for determining the detailed structure and mechanism of the ribosome; the ribosome is a complex cellular machine. It is made up of specialized RNA known as ribosomal RNA as well as dozens of distinct proteins.
The ribosomal proteins and rRNAs are arranged into two distinct ribosomal pieces of different size, known as the large and small subunit of the ribosome. Ribosomes consist of two subunits that fit together and work as one to translate the mRNA into a polypeptide chain during protein synthesis; because they are formed from two subunits of non-equal size, they are longer in the axis than in diameter. Prokaryotic ribosomes are around 20 nm in diameter and are composed of 65% rRNA and 35% ribosomal proteins. Eukaryotic ribosomes are between 25 and 30 nm in diameter with an rRNA-to-protein ratio, close to 1. Crystallographic work has shown that there are no ribosomal proteins close to the reaction site for polypeptide synthesis; this suggests that the protein components of ribosomes do not directly participate in peptide bond formation catalysis, but rather that these proteins act as a scaffold that may enhance the ability of rRNA to synthesize protein. The ribosomal subunits of bacteria and eukaryotes are quite similar.
The unit of measurement used to describe the ribosomal subunits and the rRNA fragments is the Svedberg unit, a measure of the rate of sedimentation in centrifugation rather than size. This accounts for why fragment names do not add up: for example, bacterial 70S ribosomes are made of 50
Sergio Arturo Castro Martínez is a Mexican humanitarian who resides in San Cristóbal de las Casas, Mexico. He is by training an agricultural engineer and veterinarian. However, by nature he is a true humanitarian and polyglot. Sergio has spent more than 45 years helping to build schools, develop water treatment systems and provide wound care for burn victims for the many indigenous cultures and Mexican people of Chiapas, he travels daily to the surrounding indigenous villages and marginalized urban areas to care for the health and social development needs of the under served. Yok Chij Association is his Mexican registered charitable organization. Sergio has followers from around the world who support his efforts with monetary donations and supplies to treat his burn patients, he receives payments from his patients. He has helped to build more than 35 schools and numerous water catchment and treatment systems in the San Cristóbal area and surrounding Maya villages. Museo de Trajes Regionales - Over the years, for his service, Sergio has been given tribal garb, masks and decorative items from the villagers he has helped.
He displays these items in his museum at #38 Guadalupe Victoria in San Cristóbal de Las Casas, Mexico. The museum serves as his daily walk-in clinic for the needy from 4-7pm, after which he gives tours to large and small groups; the tour includes a detailed review of the various tribal wear, people's customs and a slide show of the native Maya people. Sergio has received much recognition for his humanitarian efforts including the Medal of Merit Sancristobalense on March 31, 2009, presented to him by Municipal Council in a ceremony at the Municipal Palace. Yok Chij Charity Sergio Docu Trailer Heritance Website Peridido Y Alegre Blog Video of Sergio on YouTube Stichting Chiapas Indianen - Dutch website Portrait of a Healer-by Benjamin Mariotte, Jan 22, 2012
Seres is headquartered in Santa Clara, California, in Silicon Valley. The company creates electric components; the company, a subsidiary of Chongqing Sokon Industry Group, has established several R&D facilities and is in the process of designing and producing a U. S.-based, electric vehicle line. The company has delayed launching a US product and laid off hundreds of workers, including 90 people at its design studio; the company is partnering with a number of automotive and tech suppliers. Seres was founded as SF Motors in Silicon Valley in January 2016 as a company focused on delivering electric vehicles. In early 2017, SF Motors’ parent company, Sokon Industry Group, was granted production permits from the Chinese government to produce electric vehicles; the company has established seven R&D facilities in four countries, including the U. S. China and Germany, with Japan coming online soon. Along with establishing an R&D center in the Ann Arbor area in Michigan. SF Motors hosted its first University of Michigan-Sokon Autonomous Driving Seminar in August 2017.
All of Seres’ R&D facilities will focus on intelligent e-powertrain technology, vehicle engineering, intelligent driving systems, next-generation battery technology and lightweight designs. In 2017, SF Motors completed the acquisition of the AM General Commercial Assembly Plant in Mishawaka, making it the only electric vehicle company at the time to have manufacturing facilities in both the U. S. and China. It will be the first manufacturing plant in the U. S., wholly owned by SF Motors. The acquisition includes retaining about 430 employees at the facility who helped build vehicles for both Mercedes-Benz and Hummer. In order to secure a space for its leaders and prospective employees, the company recruited design firm AAI to build out its Santa Clara, California headquarters, which opened in March 2017; the four-story building offers 80,000 square feet, can accommodate more than 200 people. The building has a garage with EV charging stations. January 28, 2016 — SF Motors was founded in Silicon Valley, California September 2016 — Tesla co-founder Martin Eberhard joined SF Motors as Strategic Advisor January 2017 — Parent company of SF Motors granted production permit from Chinese Government to produce electric vehicles March 2017 — SF Motors opens headquarters in Silicon Valley April 2017 — Parent company of SF Motors, Sokon Motors, University of Michigan announce plans to establish Michigan-Sokon Research Center June 2017 — SF Motors announces plans to acquire commercial automotive assembly plant in Mishawaka, Indiana from AM General where Hummer H2 SUVs were built.
July 2017 — SF Motors hosts first Global Partnership Meeting at its headquarters in Silicon Valley July 2017 — SF Motors establishes intelligent driving research center in Beijing August 2017 — SF Motors hosts first University of Michigan-Sokon Autonomous Driving Seminar September 2017 — SF Motors’ parent company granted permission by Chinese Government to issue convertible bond worth up to 1.5 Billion RMB for SF Motors October 2017 — SF Motors announced the acquisition of InEVit Inc. an electric vehicle battery modularization startup headed by Martin Eberhard, industry leader and co-founder of Tesla, who joined the company as Chief Scientist and Vice Chairman of SF Motors’ Board. March 2018 — SF Motors unveils its cars, two all-electric sport utility sedans, the midsize SF5 and the large SF7. July 2019 — Plans to assemble the company’s first vehicle, an SUV called the SF5, have been halted for the U. S. market. Plans to assemble and sell SF5 in China continue unchanged. Layoffs have been announced at the company’s California headquarters.