FACTOID # 4: Just 1% of the houses in Nevada were built before 1939.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Ribosome" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Ribosome
Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). Side and front view.
(1) Head. (2) Platform. (3) Base. (4) Ridge. (5) Central protuberance. (6) Back. (7) Stalk. (8) Front.

Ribosomes (from ribonucleic acid and "greek: soma (meaning body)") are complexes of RNA and protein that are found in all cells. Prokaryotic ribosomes from archaea and bacteria are smaller than most of the ribosomes from eukaryotes such as plants and animals. However, the ribosomes in the mitochondrion of eukaryotic cells resemble those in bacteria, reflecting the evolutionary origin of this organelle. Front and back view of the two subunits of a ribosome I got this from http://www. ... Left: An RNA strand, with its nitrogenous bases. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... Prokaryotic bacteria cell structure Prokaryotes (IPA: //) are a group of organisms that lack a cell nucleus (= karyon), or any other membrane-bound organelles. ... Phyla Crenarchaeota Euryarchaeota Korarchaeota Nanoarchaeota ARMAN The Archaea (), or archaebacteria, are a major group of microorganisms. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... For other uses, see Plant (disambiguation). ... For other uses, see Animal (disambiguation). ... Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed organelle that is found in most eukaryotic cells. ... Schematic of typical animal cell, showing subcellular components. ...


The function of ribosomes is the assembly of proteins, in a process called translation. Ribosomes do this by catalysing the assembly of individual amino acids into polypeptide chains, this involves binding a messenger RNA and then using this as a template to join together the correct sequence of amino acids. This reaction uses adapters called transfer RNA molecules, which read the sequence of the messenger RNA and are attached to the amino acids. A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Translation is the second stage of protein biosynthesis (part of the overall process of gene expression). ... This article is about the class of chemicals. ... The life cycle of an mRNA in a eukaryotic cell. ... Transfer RNA Transfer RNA (abbreviated tRNA), first hypothesized by Francis Crick, is a small RNA chain (73-93 nucleotides) that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. ...

Contents

Description

Ribosomes are about 20nm (200 Ångström) in diameter and are composed of 65% ribosomal RNA and 35% ribosomal proteins (known as a Ribonucleoprotein or RNP). They translate messenger RNA (mRNA) to build polypeptide chains (e.g., proteins) using amino acids delivered by transfer RNA (tRNA). They mostly comprise proteins[citation needed] yet their active sites are made of RNA, so ribosomes are now classified as "ribozymes".[1] To help compare different orders of magnitude this page lists lengths between 10 nm and 100 nm (10-8 and 10-7 m). ... A nanometre (American spelling: nanometer, symbol nm) (Greek: νάνος, nanos, dwarf; μετρώ, metrÏŒ, count) is a unit of length in the metric system, equal to one billionth of a metre (or one millionth of a millimetre), which is the current SI base unit of length. ... An Ã¥ngström or aangstroem (the official transliteration), or angstrom (symbol Ã…) is a non-SI unit of length that is internationally recognized, equal to 0. ... Ribosomal RNA (rRNA), a type of RNA synthesized in the nucleolus by RNA Pol I, is the central component of the ribosome, the protein manufacturing machinery of all living cells. ... A ribosomal protein is any of the proteins that, in conjunction with rRNA, make up the ribosomal subunits involved in the cellular process of translation. ... Ribonucleoprotein(RNP) is a compound that combined ribonucleic acid (RNA) and protein together. ... Translation is the second process of protein biosynthesis (part of the overall process of gene expression). ... The interaction of mRNA in a eukaryote cell. ... Peptides are the family of molecules formed from the linking, in a defined order, of various amino acids. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Transfer RNA (abbreviated tRNA) is a small RNA chain (74-93 nucleotides) that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. ... // A ribozyme (from ribonucleic acid enzyme, also called RNA enzyme or catalytic RNA) is an RNA molecule that catalyzes a chemical reaction. ...


Ribosomes build proteins from the genetic instructions held within messenger RNA. Free ribosomes are suspended in the cytosol (the semi-fluid portion of the cytoplasm); others are bound to the rough endoplasmic reticulum, giving it the appearance of roughness and thus its name, or to the nuclear envelope. As ribozymes, partly consituted from RNA, it is thought that they might be remnants of the RNA world.[2] Catalysis of the peptide bond involves the C2 hydroxyl of RNA's P-site adenosine in a protein shuttle mechanism. The full function (i.e. translocation) of the ribosome is reliant on changes in protein conformations. Ribosomes are sometimes referred to as organelles, but the use of the term organelle is contested and is falling from favor. The life cycle of an mRNA in a eukaryotic cell. ... The cytosol (cf. ... Cross section of cell with cytoplasm labeled at center right. ... The endoplasmic reticulum or ER (endoplasmic means within the cytoplasm, reticulum means little net) is an organelle found in all eukaryotic cells. ... The nuclear envelope (also known as the perinuclear envelope, nuclear membrane, nucleolemma or karyotheca) is the double membrane of the nucleus that encloses genetic material in eukaryotic cells. ... The RNA world hypothesis proposes that RNA was, before the emergence of the first cell, the dominant, and probably the only, form of life. ... A peptide bond is a chemical bond that is formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O). ... Schematic of typical animal cell, showing subcellular components. ...


Ribosomes are an extremely important structure in the cell. Ribosomes were first observed in the mid-1950s by Romanian cell biologist George Palade using an electron microscope as dense particles or granules[3] for which he would win the Nobel Prize. The term "ribosome" was proposed by scientist Richard B. Roberts in 1958: Dr. Palade won the Nobel Prize in 1974. ... An electron microscope is a type of microscope that uses electrons as a way to illuminate and create an image of a specimen. ... The Nobel Prize (Swedish: ) was established in Alfred Nobels will in 1895, and it was first awarded in Physics, Chemistry, Physiology or Medicine, Literature, and Peace in 1901. ...

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; to others, the microsomes consist of protein and lipid contaminated by particles. The phrase “microsomal particles” does not seem adequate, and “ribonucleoprotein particles of the microsome fraction” is much too awkward. During the meeting the word "ribosome" was suggested; this seems a very satisfactory name, and it has a pleasant sound. The present confusion would be eliminated if “ribosome” were adopted to designate ribonucleoprotein particles in sizes ranging from 35 to 100S.

Roberts, R. B., Microsomal Particles and Protein Synthesis[4]

The structure and function of the ribosomes and associated molecules, known as the translational apparatus, has been of research interest since the mid-twentieth century and is a very active field of study today.

Figure 2 : Large (1) and small (2) subunit fit together
Figure 2 : Large (1) and small (2) subunit fit together

Ribosomes consist of two subunits (Figure 1) that fit together (Figure 2) and work as one to translate the mRNA into a polypeptide chain during protein synthesis (Figure 3). Prokaryotic subunits consist of one or two and eukaryotic of one or three very large RNA molecules (known as ribosomal RNA or rRNA) and multiple smaller protein molecules. 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 act as a scaffold that may enhance the ability of rRNA to synthesize protein rather than directly participating in catalysis (See: Ribozyme). Image File history File links No higher resolution available. ... The interaction of mRNA in a eukaryote cell. ... Prokaryotes are unicellular (in rare cases, multicellular) organisms without a nucleus. ... Kingdoms Eukaryotes are organisms with complex cells, in which the genetic material is organized into membrane-bound nuclei. ... Left: An RNA strand, with its nitrogenous bases. ... A non-coding RNA (ncRNA) is any RNA molecule that functions without being translated into a protein. ... Crystallography (from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and graphein = write) is the experimental science of determining the arrangement of atoms in solids. ... // A ribozyme (from ribonucleic acid enzyme, also called RNA enzyme or catalytic RNA) is an RNA molecule that catalyzes a chemical reaction. ...


Biogenesis

Main article: Ribosome biogenesis

In prokaryotic cells, ribosomes synthesize with cytoplasm to enable the transcription of multiple ribosome gene operons. In eukaryotes and some prokaryotic cells, the process takes place both in the cell cytoplasm and in the nucleolus of eukaryotic cells. It involves the coordinated function of over 200 proteins in the synthesis and processing of the four rRNAs, as well as assembly of those rRNAs with the ribosomal proteins. Ribosome biogenesis, the process of making ribosomes, takes place both in the cell cytoplasm and in the nucleolus of eukaryotic cells. ... A micrograph of ongoing gene transcription of ribosomal RNA illustrating the growing primary transcripts. ... An operon is a group of key nucleotide sequences including an operator, a common promoter, and one or more structural genes that are controlled as a unit to produce messenger RNA (mRNA). ...


Ribosome locations

Ribosomes are classified as being either "free" or "membrane-bound".


Free ribosomes

Free ribosomes are "free" to move about anywhere in the cytoplasm (within the cell membrane). Proteins formed from free ribosomes are used within the cell. Proteins containing disulfide bonds using cysteine amino acids cannot be produced outside of the lumen of the endoplasmic reticulum. Cross section of cell with cytoplasm labeled at center right. ... Look up cell membrane in Wiktionary, the free dictionary. ... A disulfide bond (SS-bond), also called a disulfide bridge, is a strong covalent bond between two sulfhydryl groups. ... Cysteine is a naturally occurring, sulfur-containing amino acid that is found in most proteins, although only in small quantities. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... artery anatomy, showing lumen The lumen (pl. ...


Membrane-bound ribosomes

When certain proteins are synthesized by a ribosome they can become "membrane-bound". The newly produced polypeptide chains are inserted directly into the endoplasmic reticulum by the ribosome and are then transported to their destinations. Bound ribosomes usually produce proteins that are used within the cell membrane or are expelled from the cell via exocytosis. The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins to be used in the cell membrane (e. ... Neuron A (transmitting) to neuron B (receiving) 1. ...


Free and membrane-bound ribosomes differ only in their spatial distribution; they are identical in structure and function. Whether the ribosome exists in a free or membrane-bound state depends on the presence of a ER-targeting signal sequence on the protein being synthesized. A signal peptide is a short (15-60 amino acids long) peptide chain that directs the post transrational transport of a protein. ...


Structure

Atomic structure of the 30S Subunit from Thermus thermophilus. Proteins are shown in blue and the single RNA strand in orange.
Atomic structure of the 30S Subunit from Thermus thermophilus. Proteins are shown in blue and the single RNA strand in orange.[5]

The ribosomal subunits of prokaryotes and eukaryotes are quite similar.[6] Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Prokaryotic bacteria cell structure Prokaryotes (IPA: //) are a group of organisms that lack a cell nucleus (= karyon), or any other membrane-bound organelles. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ...


Prokaryotes have 70S ribosomes, each consisting of a small (30S) and a large (50S) subunit. Their large subunit is composed of a 5S RNA subunit (consisting of 120 nucleotides), a 23S RNA subunit (2900 nucleotides) and 34 proteins. The 30S subunit has a 1540 nucleotide RNA subunit bound to 21 proteins.[6] A Svedberg (symbol S, sometimes Sv) is a non-SI physical unit used in ultracentrifugation. ... Centuries: 1st century BC - 1st century - 2nd century Decades: 20s BC - 10s BC - 0s - 10s - 20s - 30s - 40s - 50s - 60s - 70s - 80s 30 31 32 33 34 35 36 37 38 39 Sometimes the 30s is used as shorthand for the 1930s, the 1830s, or other such decades in various... Centuries: 1st century BC - 1st century - 2nd century Decades: 0s - 10s - 20s - 30s - 40s - 50s - 60s - 70s - 80s - 90s - 100s 50 51 52 53 54 55 56 57 58 59 Sometimes the 50s is used as shorthand for the 1950s, the 1850s, or other such decades in various centuries Events... 5S ribosomal RNA (5S rRNA) is a component of the large ribosomal subunit in both prokaryotes and eukaryotes. ... Left: An RNA strand, with its nitrogenous bases. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ...


Eukaryotes have 80S ribosomes, each consisting of a small (40S) and large (60S) subunit. Their large subunit is composed of a 5S RNA (120 nucleotides), a 28S RNA (4700 nucleotides), a 5.8S subunit (160 nucleotides) and ~49 proteins. The 40S subunit has a 1900 nucleotide (18S) RNA and ~33 proteins.[6] Centuries: 1st century BC - 1st century - 2nd century Decades: 10s - 20s - 30s - 40s - 50s - 60s - 70s - 80s - 90s - 100s - 110s 60 61 62 63 64 65 66 67 68 69 Note: Sometimes the 60s is used as shorthand for the 1960s, the 1860s, or other such decades in various centuries...


The ribosomes found in chloroplasts and mitochondria of eukaryotes also consist of large and small subunits bound together with proteins into one 70S particle.[6] These organelles are believed to be descendants of bacteria (see Endosymbiotic theory) and as such their ribosomes are similar to those of prokaryotes.[7] Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ... In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... In cell biology, an organelle is one of several structures with specialized functions, suspended in the cytoplasm of a eukaryotic cell. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... It has been suggested that Proto-mitochondrion be merged into this article or section. ...


The various ribosomes share a core structure which is quite similar despite the large differences in size. The extra RNA in the larger ribosomes is in several long continuous insertions, such that they form loops out of the core structure without disrupting or changing it.[6] All of the catalytic activity of the ribosome is carried out by the RNA, the proteins reside on the surface and seem to stabilize the structure.[6] Left: An RNA strand, with its nitrogenous bases. ... // A ribozyme (from ribonucleic acid enzyme, also called RNA enzyme or catalytic RNA) is an RNA molecule that catalyzes a chemical reaction. ...


The differences between the prokaryotic and eukaryotic ribosomes are exploited by pharmaceutical chemists to create antibiotics that can destroy a bacterial infection without harming the cells of the infected person. Due to the differences in their structures, the bacterial 70S ribosomes are vulnerable to these antibiotics while the eukaryotic 80S ribosomes are not.[8] Even though mitochondria possess ribosomes similar to the bacterial ones, mitochondria are not affected by these antibiotics because they are surrounded by a double membrane that does not easily admit these antibiotics into the organelle.[9] Medicinal or pharmaceutical chemistry is a scientific discipline at the intersection of chemistry and pharmacy involved with designing, synthesizing and developing pharmaceutical drugs. ... Staphylococcus aureus - Antibiotics test plate. ... In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ... Schematic of typical animal cell, showing subcellular components. ...


Atomic structure

Atomic structure of the 50S Subunit from Haloarcula marismortui. Proteins are shown in blue and the two RNA strands in orange and yellow. The small patch of green in the center of the subunit is the active site.
Atomic structure of the 50S Subunit from Haloarcula marismortui. Proteins are shown in blue and the two RNA strands in orange and yellow.[10] The small patch of green in the center of the subunit is the active site.

The general molecular structure of the ribosome has been known since the early 1970s. In the early 2000s the structure has been achieved at high resolutions, in the order of a few Ångströms. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The 1970s decade refers to the years from 1970 to 1979, also called The Seventies. ... This article is about the first decade of the 21st century. ... An Ã¥ngström or aangstroem (the official transliteration), or angstrom (symbol Ã…) is a non-SI unit of length that is internationally recognized, equal to 0. ...


The first papers giving the structure of the ribosome at atomic resolution, were published in rapid succession in late 2000. First, the 50S (large prokaryotic) subunit from the archea, Haloarcula marismortui was published.[10] Soon after the structure of the 30S subunit from Thermus thermophilus was published.[5] Shortly thereafter a more detailed structure was published.[11] Early the next year (May 2001) these coordinates were used to reconstruct the entire T. thermophilus 70S particle at 5.5 Ångström resolution.[12] Year 2000 (MM) was a leap year starting on Saturday (link will display full 2000 Gregorian calendar). ... Phyla / Classes Phylum Crenarchaeota Phylum Euryarchaeota     Halobacteria     Methanobacteria     Methanococci     Methanopyri     Archaeoglobi     Thermoplasmata     Thermococci Phylum Korarchaeota Phylum Nanoarchaeota The Archaea are a major group of prokaryotes. ... Binomial name Thermus thermophilus Thermus thermophilus is a gram negative eubacterium used in a range of biotechnological applications, including as a model organism for genetic manipulation and systems biology. ... Year 2001 (MMI) was a common year starting on Monday (link displays the 2001 Gregorian calendar). ... Binomial name Thermus thermophilus Thermus thermophilus is a gram negative eubacterium used in a range of biotechnological applications, including as a model organism for genetic manipulation and systems biology. ... You have big harry skanky balls ...


Two papers were published in November 2005 with structures of the Escherichia coli 70S ribosome. The structures of vacant ribosome were determined at 3.5 Ångström resolution using x-ray crystallography.[13] Then, two weeks later, a structure based on cryo-electron microsopy was published,[14] which depicts the ribosome at 11-15 Ångström resolution in the act of passing a newly synthesized protein strand into the protein-conducting channel. For other uses, see November (disambiguation). ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... E. coli redirects here. ... You have big harry skanky balls ... X-ray crystallography, also known as single-crystal X-ray diffraction, is the oldest and most common crystallographic method for determining the structure of molecules. ... An electron microscope is a type of microscope that uses electrons as a way to illuminate and create an image of a specimen. ... To help compare different orders of magnitudes this page lists lengths between 10-9 m (metre) and 10-8 m (1 nm and 10 nm). ...


First atomic structures of the ribosome complexed with tRNA and mRNA molecules were solved by using X-ray crystallography by two groups independently, at 2.8 Ångström[15] and at 3.7 Ångström.[16] These structures allow one to see the details of interactions of the Thermus thermophilus ribosome with mRNA and with tRNAs bound at classical ribosomal sites. Interactions of the ribosome with long mRNAs containing Shine-Dalgarno sequences were visualized soon after that at 4.5 to 5.5 Ångström resolution.[17] Transfer RNA (abbreviated tRNA) is a small RNA chain (74-93 nucleotides) that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. ... The interaction of mRNA in a eukaryote cell. ... You have big harry skanky balls ... You have big harry skanky balls ... Binomial name Thermus thermophilus Thermus thermophilus is a gram negative eubacterium used in a range of biotechnological applications, including as a model organism for genetic manipulation and systems biology. ... The interaction of mRNA in a eukaryote cell. ... Transfer RNA (abbreviated tRNA) is a small RNA chain (74-93 nucleotides) that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. ... You have big harry skanky balls ...


Function

Main article: Translation (biology)

Ribosomes are the workhorses of protein biosynthesis, the process of translating messenger RNA (mRNA) into protein. The mRNA comprises a series of codons that dictate to the ribosome the sequence of the amino acids needed to make the protein. Using the mRNA as a template, the ribosome traverses each codon of the mRNA, pairing it with the appropriate amino acid. This is done using molecules of transfer RNA (tRNA) containing a complementary anticodon on one end and the appropriate amino acid on the other. Translation is the second stage of protein biosynthesis (part of the overall process of gene expression). ... Protein biosynthesis (synthesis) is the process in which cells build proteins. ... The life cycle of an mRNA in a eukaryotic cell. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... RNA codons. ... This article is about the class of chemicals. ... Transfer RNA Transfer RNA (abbreviated tRNA), first hypothesized by Francis Crick, is a small RNA chain (73-93 nucleotides) that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. ... An anticodon is a unit made up of nucleotides that plays an important role in various DNA cycles, including DNA transcription. ...


Protein synthesis begins at a start codon near the 5' end of the mRNA. The small ribosomal subunit, typically bound to a tRNA containing the amino acid methionine, binds to an AUG codon on the mRNA and recruits the large ribosomal subunit. The large ribosomal subunit contains three tRNA binding sites, designated A, P, and E. The A site binds an aminoacyl-tRNA (a tRNA bound to an amino acid); the P site binds a peptidyl-tRNA (a tRNA bound to the peptide being synthesized); and the E site binds a free tRNA before it exits the ribosome. ATG and AUG denote sequences of DNA and RNA respectively that are the start codon or initiation codon encoding the amino acid methionine (Met) in eukaryotes and a modified Met (fMet) in prokaryotes. ... Methionine is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CH2SCH3. ...

Figure 3 : Translation of mRNA (1) by a ribosome (2) into a polypeptide chain (3). The mRNA begins with a start codon (AUG) and ends with a stop codon (UAG).

In Figure 3, both ribosomal subunits (small and large) assemble at the start codon (towards the 5' end of the mRNA). The ribosome uses tRNA which matches the current codon (triplet) on the mRNA to append an amino acid to the polypeptide chain. This is done for each triplet on the mRNA, while the ribosome moves towards the 3' end of the mRNA. Usually in bacterial cells, several ribosomes are working parallel on a single mRNA, forming what we call a polyribosome or polysome. Operation of ribosome http://www. ... RNA codons. ... Transfer RNA (abbreviated tRNA) is a small RNA chain (74-93 nucleotides) that transfers a specific amino acid to a growing polypeptide chain at the ribosomal site of protein synthesis during translation. ... This article is about the class of chemicals. ... Polysomes (polyribosomes) are free ribosomes engaged in protein synthesis and may appear as clusters, linear arrays, or rosetts in routine. ...


References

  1. ^ Rodnina MV, Beringer M, Wintermeyer W (2007). "How ribosomes make peptide bonds". Trends Biochem. Sci. 32 (1): 20-6. doi:10.1016/j.tibs.2006.11.007. PMID 17157507. 
  2. ^ Cech T (2000). "Structural biology. The ribosome is a ribozyme". Science 289 (5481): 878-9. PMID 10960319. 
  3. ^ G.E. Palade. (1955) "A small particulate component of the cytoplasm." J Biophys Biochem Cytol. Jan;1(1): pages 59-68. PMID 14381428
  4. ^ Roberts, R. B., editor. (1958) "Introduction" in Microsomal Particles and Protein Synthesis. New York: Pergamon Press, Inc.
  5. ^ a b Schluenzen F, Tocilj A, Zarivach R, Harms J, Gluehmann M, Janell D, Bashan A, Bartels H, Agmon I, Franceschi F, Yonath A (2000). "Structure of functionally activated small ribosomal subunit at 3.3 angstroms resolution". Cell 102 (5): 615-23. PMID 11007480. 
  6. ^ a b c d e f The Molecular Biology of the Cell, fourth eddition. Brusce Alberts, et al. Garland Science (2002) pg. 342 ISBN 0-8153-3218-1
  7. ^ The Molecular Biology of the Cell, fourth edition. Brusce Alberts, et al. Garland Science (2002) pg. 808 ISBN 0-8153-3218-1
  8. ^ Recht MI, Douthwaite S, Puglisi JD (1999). "Basis for prokaryotic specificity of action of aminoglycoside antibiotics". EMBO J 18 (11): 3133-8. PMID 10357824. 
  9. ^ O'Brien, T.W., The General Occurrence of 55S Ribosomes in Mammalian Liver Mitochondria. J. Biol. Chem., 245:3409 (1971).
  10. ^ a b Ban N, Nissen P, Hansen J, Moore P, Steitz T (2000). "The complete atomic structure of the large ribosomal subunit at 2.4 A resolution". Science 289 (5481): 905-20. PMID 10937989. 
  11. ^ Wimberly BT, Brodersen DE, Clemons WM Jr, Morgan-Warren RJ, Carter AP, Vonrhein C, Hartsch T, Ramakrishnan V. Structure of the 30S ribosomal subunit. Nature. 2000 Sep 21;407(6802):327-39. PMID 11014182
  12. ^ Yusupov MM, Yusupova GZ, Baucom A, Lieberman K, Earnest TN, Cate JH, Noller HF. Crystal structure of the ribosome at 5.5 Å resolution. Science. 2001 May 4;292(5518):883-96. Epub 2001 Mar 29. PMID 11283358
  13. ^ Schuwirth BS, Borovinskaya MA, Hau CW, Zhang W, Vila-Sanjurjo A, Holton JM, Cate JH. Structures of the bacterial ribosome at 3.5 Ångström resolution. Science. 2005 Nov 4;310(5749):827-34. PMID 16272117
  14. ^ Mitra K, Schaffitzel C, Shaikh T, Tama F, Jenni S, Brooks CL 3rd, Ban N, Frank J. Structure of the E. coli protein-conducting channel bound to a translating ribosome. Nature. 2005 Nov 17;438(7066):318-24. PMID 16292303
  15. ^ Selmer, M., Dunham, C.M., Murphy, F.V IV, Weixlbaumer, A., Petry S., Kelley, A.C., Weir, J.R. and Ramakrishnan, V. (2006). Structure of the 70S ribosome complexed with mRNA and tRNA. Science , 313, 1935-1942. PMID 16959973
  16. ^ Korostelev A, Trakhanov S, Laurberg M, Noller HF. Crystal structure of a 70S ribosome-tRNA complex reveals functional interactions and rearrangements. Cell. 2006 Sep 22;126(6):1065-77
  17. ^ Yusupova G, Jenner L, Rees B, Moras D, Yusupov M. Structural basis for messenger RNA movement on the ribosome. Nature. 2006 Nov 16;444(7117):391-4

A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... An ångström or aangstroem (the official transliteration), or angstrom (symbol Å) is a non-SI unit of length that is internationally recognized, equal to 0. ... An ångström or aangstroem (the official transliteration), or angstrom (symbol Å) is a non-SI unit of length that is internationally recognized, equal to 0. ... You have big harry skanky balls ...

See also

Translation is the second process of protein biosynthesis (part of the overall process of gene expression). ... Translation is the process in cells by which messenger RNA is read by a ribosome, and by utilising tRNA a protein is built according to the genetic code of the mRNA. This varies between prokaryotic and eukaryotic cells. ... The process of initiation of translation in eukaryotes. ... Schematic of typical animal cell, showing subcellular components. ... The nucleolus is contained within the cell nucleus. ... Wobble base pairs for inosine Wobble base pairs for Uracil A wobble base pair is a G-U and I-U / I-A / I-C pair fundamental in RNA secondary structure. ... A non-coding RNA (ncRNA) is any RNA molecule that functions without being translated into a protein. ... The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins to be used in the cell membrane (e. ... Posttranslational modification is the chemical modification of a protein after its translation. ...

External links

  • 70S Ribosome Architecture Animation of a working ribosome. Requires the Chime browser plugin from this site (where registration is required).
  • Lab computer simulates ribosome in motion
  • Role of the Ribosome, Gwen V. Childs, copied here
  • Molecule of the Month © RCSB Protein Data Bank:
    • Ribosome
    • Elongation Factors

This article contains material from the Science Primer published by the NCBI, which, as a U.S. government publication, is in the public domain. Schematic of typical animal cell, showing subcellular components. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... In spermatozoa of many animals, the acrosome is an organelle that develops over the anterior half of the spermatozoons head. ... Plant cells separated by transparent cell walls. ... Look up cell membrane in Wiktionary, the free dictionary. ... A centriole showing the nine triplets of microtubules. ... Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ... Not to be confused with Psyllium. ... For the insect anatomical structure, see Antenna (biology). ... The centrosome is the main microtubule organizing center (MTOC) of the cell as well as a regulator of cell-cycle progression. ... Cross section of cell with cytoplasm labeled at center right. ... The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins to be used in the cell membrane (e. ... In biology an endosome is a membrane-bound compartment inside cells. ... Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. ... Various organelles labeled. ... In a biological cell, a melanosome is an organelle containing melanin, the most common light-absorbing pigment found in the animal kingdom. ... Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed organelle that is found in most eukaryotic cells. ... A diagram of the structure of a Myofybril Myofibrils (obsolete term: sarcostyles) are cylindrical organelles, found within muscle cells. ... HeLa cells stained for DNA with the Blue Hoechst dye. ... The nucleolus is contained within the cell nucleus. ... Parenthesomes are found in basidiomycete fungus. ... Basic structure of a peroxisome Peroxisomes are ubiquitous organelles in eukaryotes that participate in the metabolism of fatty acids and other metabolites. ... Plant cells with visible chloroplasts. ... Schematic of typical animal cell, showing subcellular components. ... In cell biology, a vesicle is a relatively small and enclosed compartment, separated from the cytosol by at least one lipid bilayer. ... National Center for Biotechnology Information logo The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ...


  Results from FactBites:
 
Ribosome - Wikipedia, the free encyclopedia (1173 words)
A ribosome is an organelle composed of ribosomal RNA and ribosomal proteins known as a Ribonucleoproteinor RNP.
Ribosomes were first observed in the mid-1950s by Romanian-born American cell biologist George Palade in the electron microscope as dense particles or granules.
The ribosome uses tRNA (transfer RNAs which are RNA molecules that carry an amino acid and present the matching anti-codon, according to the genetic code, to the ribosome) which matches the current codon (triplet) on the mRNA to append an amino acid to the polypeptide chain.
Ribosome (432 words)
Ribosomes are found in the cytosol (the internal fluid of the cell) of all cells.
Free ribosomes usually produce proteins that are used in the cytosol or in the organelle they occur in.
The ribosome uses tRNA[transfer RNAs are RNA molecules that carry an amino acid and present the matching codon, according to the genetic code, to the ribosome.] which matches the current triplet on the mRNA to append an amino acid to the polypeptide chain.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m