[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$f2kMfxQC4kqLWmQAZ3d9CTscmcsqUXblW5b-SZyaIWWQ":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":112,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":177},[4,8,12,16,20,24,28,32],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Abbreviations","abbreviations","\u002Fabbreviations\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"title":33,"slug":34,"path":35},"Utilization Tests for Bacterial Identification","utilization-tests","\u002Futilization-tests\u002F",{"type":37,"data":38},"blog",{"slug":39,"title":40,"description":41,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":44,"lastUpdatedDate":45,"draft":46,"category":47,"image":42,"body":48,"faq":49,"commentsClosed":46,"tags":74,"related":76,"comments":108},"translation-protein-synthesis","RNA Translation: Major Steps of Protein Synthesis","\u003Cp>Translation is how a cell reads mRNA and builds a protein. Learn the three main steps (initiation, elongation, termination), how the ribosome, tRNA, and codons work together, and where it happens.\u003C\u002Fp>",null,"Ashma Shrestha","2022-08-08","2026-08-15",false,"molecular-biology","A gene is a set of instructions, but instructions alone do not do anything. They have to be read and acted on. Translation is the step where the cell finally reads the genetic message and builds the thing it codes for: a protein. It is the last stage of turning a gene into a working product, and it is happening in your cells right now, thousands of times a second.\n\nThe name is a good clue to what happens. The message in mRNA is written in the \"language\" of nucleotides (the bases A, U, G, C), but a protein is written in the \"language\" of amino acids. Translation converts one language into the other. This article explains how that conversion works: where it happens, the parts involved, and the main steps of initiation, elongation, and termination.\n\nThe DNA (deoxyribonucleic acid) has all the genetic instructions necessary for the proper functioning of any cell. The process of expressing genetic instructions in DNA into functional products (proteins) is called gene expression\u002Fprotein synthesis. The gene expression occurs by the two processes viz; **transcription and translation**.\n\nProteins are vital components for both structural and functional roles in cells. Therefore, synthesizing protein (translation) is an essential task the cell performs. The ribosome, mRNA, and tRNA (transfer RNA) plays vital role in protein synthesis. As mentioned earlier, the DNA has all the required information that the mRNA decodes and then converts the decoded message to amino acids.\n\n![Translation - Source:https:\u002F\u002Fwww.genome.gov\u002Fgenetics-glossary\u002FTranslation](\u002Fblogs\u002FTranslation.jpg)Figure: Source:https:\u002F\u002Fwww.genome.gov\u002Fgenetics-glossary\u002FTranslation\n\n## **What is translation?**\n\nTranslation is the process of building a protein from the instructions carried by messenger RNA (mRNA). It is the second step of gene expression. The first step, transcription, copies a gene from DNA into mRNA. Translation then reads that mRNA and uses it to join amino acids into a protein.\n\nThe key to translation is the genetic code. The mRNA is read in groups of three bases called codons. Each codon stands for one amino acid. For example, the codon AUG codes for methionine and also acts as the \"start\" signal. There are 64 codons in total: 61 that code for amino acids and 3 that act as \"stop\" signals.\n\n**Three kinds of molecule do the work:**\n\n1. mRNA carries the message, read in codons.\n2. tRNA (transfer RNA) is the adapter. Each tRNA carries one specific amino acid at one end and has a three-base anticodon at the other end that matches a codon on the mRNA. This is how the right amino acid is brought to the right place.\n3. The[ ribosome is the machine](https:\u002F\u002Fmicrobeonline.com\u002Fribosomes-types-structure-and-function\u002F). It holds the mRNA and the tRNAs in place and joins the amino acids together. It is made of ribosomal RNA (rRNA) and proteins.\n\nThe result of translation is a chain of amino acids, called a polypeptide, which then folds into a working protein. So the end product of translation is a protein (a polypeptide), not an amino acid.\n\n## **The three main steps at a glance**\n\nTranslation is usually described in three main steps, after a preparation step:\n\nPreparation (activation or \"charging\"): each amino acid is attached to its matching tRNA, ready for use.\n\n1. **Initiation**: the ribosome assembles on the mRNA at the start codon (AUG), with the first tRNA in place.\n2. **Elongation**: the ribosome moves along the mRNA one codon at a time, adding one amino acid for each codon, building the chain.\n3. **Termination**: the ribosome reaches a stop codon, the finished protein is released, and the ribosome comes apart.\n\nThe sections below explain each step in detail.\n\n## Where does it occur?\n\nThe entire translation process occurs inside the cell organelle-**ribosomes** (made up of proteins and RNA). The ribosomes have two subunits; **70s (30s and 50s) in prokaryotes and 80s (40s and 60s) in eukaryotes.** The subunits are made up of rRNA (ribosomal RNA) and proteins. *(The tRNA is a separate molecule that visits the ribosome during translation; it is not part of the ribosome itself).*\n\nThe two subunits have a small opening called a cleft and stay separated in normal conditions inside the cytoplasm. The mRNA passes through the cleft during protein synthesis. The tRNA acts like an adapter molecule; one end reads the codons in the mRNA, and the other binds to the specific amino acid. The aminoacyl-tRNA and mRNA are held closely together for complementary base pairing. The rRNA adds the newly synthesized amino acid to the growing chain of a polypeptide during translation.\n\n> aminoacyl tRNA- tRNA that is bound with amino acid.\n\n## Steps or Stages of Translation\u002FProtein Synthesis\n\nTranslation has three main steps: initiation, elongation, and termination. Before these can happen, there is a preparation step called activation (or charging), in which each amino acid is attached to its tRNA. Counting this preparation step, the process is sometimes described as four stages: activation, initiation, elongation, and termination. Each is explained below.\n\n### Activation of amino acids\n\nBefore synthesizing protein, amino acids (the essential compound for protein) must be activated. The activation of amino acids occurs with the help of tRNA, which translates the nucleic acid language into the language of proteins. The carboxyl group of amino acids takes part in activation. The enzyme aminoacyl tRNA synthetase catalyzes the reactions. The activation occurs in two steps; **the formation of aminoacyl adenylate and the formation of aminoacyl tRNA.**\n\n\\*\\*Step 1: Formation of aminoacyl adenylate-\\*\\*The carboxyl group of amino acids binds with ɑ-phosphate of ATP by forming a high-energy acyl bond and aminoacyl adenylate (aa-AMP) as the end product. The 𝛽 and 𝛄 phosphates are released as PPi. The enzyme aminoacyl tRNA synthetase catalyzes the reaction in the presence of magnesium ions (Mg++).\n\nAmino acid + ATP → Amino acyl adenylate (aa-AMP) + PPi; in the presence of aminoacyl tRNA synthetase and Mg++.\n\n**Step 2: Formation of aminoacyl tRNA-** Thus formed aminoacyl adenylate reacts with tRNA in the presence of the enzyme aminoacyl tRNA synthetase and Mg++ forming aminoacyl tRNA and AMP as products. A high-energy ester bond is formed between the carboxyl group of amino acids and the 3′ hydroxyl group of terminal adenosine of tRNA.\n\nAminoacyl adenylate + tRNA → Aminoacyl tRNA + AMP; in the presence of aminoacyl tRNA synthetase and Mg++\n\n**Overall reaction:**\n\nAmino acid+ ATP + tRNA → Aminoacyl tRNA + AMP + PPi; enzyme- aminoacyl tRNA and Mg++\n\n### Initiation of polypeptide synthesis\n\nFor initiation of polypeptide synthesis\u002Ftranslation, a few components are required. They are; ribosomes, mRNA with the codons, and tRNA with methionine (first amino acids coded by AUG).\n\nThe first step is the activation of methionine\n\nThe step in eukaryotes is similar to activating any amino acids. Whereas, in prokaryotes, the activated methionine is treated with N10-formyl tetrahydrofolate and forms fmet-tRNA.\n\n**In eukaryotes,**\n\nMethionine + ATP +tRNA → met-tRNA + AMP + PPi; in the presence of enzyme methionyl tRNA synthetase and Mg++.\n\n**In prokaryotes,**\n\nTransformylase enzyme transfers a formyl group from the N10-formyl tetrahydrofolate to the amino group of met-tRNA. The transfer of the N formyl group prevents fmet from entering the polypeptide chain’s interior position.\n\n1. Methionine + ATP +tRNA → met-tRNA + AMP + PPi; in the presence of enzyme methionyl tRNA synthetase and Mg++\n2. N10-formyl tetrahydrofolate + met-tRNA → fmet-tRNA + tetrahydrofolate\n\nThe second step is slightly different in eukaryotes and prokaryotes\n\n![ - Initiation of translation in prokaryotes](\u002Fblogs\u002Fintiation-step-in-prokaryotes.png)Figure: Initiation of translation in prokaryotes\n\n**In prokaryotes,** three initiation factors, IF1, IF2, and IF3, are essential after the activation of methionine.\n\n1. The 30s ribosomal subunit binds to the IF1 and IF3; here, the IF3 prevents prematurely combining the larger (50s) and the smaller subunits (30s).\n2. Then the mRNA binds to the smaller subunit; the Shine-Dalgarno sequence points to the initiating 5′ AUG in the mRNA.\n3. The interaction of mRNA and 16s rRNA determines the precise position of the 5′ AUG.\n4. Three sites form during the interaction of mRNA and the 30s subunit of the ribosome. A-site: Aminoacyl site where the IF2 binds, P-site: Peptidyl site (AUG binds), and E-site is the exit site. The 5′ AUG is confined in the P-site and attaches to the fmet-tRNA with the help of GTP and IF2.\n5. The GTP hydrolyzes and releases all the initiation factors. The newly formed complex (30s subunit + mRNA + fmet-tRNA) combines with the 50s subunit and forms the initiation complex. The initiation complex has 70s ribosome, mRNA, and fmet-tRNA\n\n**In eukaryotes,** the multiple initiation factor eIF has similar functions to the initiation factor of the prokaryotes. For example, eIF3 and eIF1A and analogs to IF3 and IF1, respectively, eIF2 and eIF2B are two GTP binding proteins, etc. The activated met-tRNA attaches to the small subunit of ribosome (the 40s). The combination (met-tRNA+ small subunit of the ribosome) binds at the 5′ end of mRNA at the GTP cap. And then, the combination moves along the mRNA in the 3′ end. It stops when it finds the start codon. The larger subunit then joins with the newly formed combination of mRNA, 40s subunit, and met-tRNA, giving rise to the initiation complex.\n\n![Initiation of translation in eukaryotes - Initiation step in eukaryotes](\u002Fblogs\u002Fintiation-step-in-eukaryotes.png)Figure: Initiation step in eukaryotes\n\n### Elongation of the polypeptide chain\n\nThe elongation of the polypeptide chain is the stage in translation where the chain of amino acids gets longer. The addition of amino acids occurs after the movement of the initiation complex in the 3′ direction of mRNA. The stage requires elongation factors. In prokaryotes these are EF-Tu, EF-Ts, and EF-G. In eukaryotes, eEF1α is the analog of EF-Tu and eEF2 is the analog of EF-G. The stage can be understood in three steps; **recognition, peptidyl transfer or transpeptidation, and translocation.**\n\n![elongation of polypeptide chains - Elongation of polypeptide chains](\u002Fblogs\u002Felongation-of-polypeptide-chain.png)Figure: Elongation of polypeptide chains\n\nRecognition\n\nThe P-site in the initiation complex is occupied by the met-tRNA (in eukaryotes) and fmet-tRNA (in prokaryotes). So, the recognition step occurs in the A-site of the initiation complex. The recognition has the following steps:\n\n1. A molecule of aminoacyl tRNA attaches to the A-site, which has a sequence of three bases complementary to the anticodon on tRNA.\n2. Two elongation factors (EFTU and EFTS) and GTP have roles in this step.\n3. EFTU firstly binds to the GTP. The EFTU-GTP then binds to aminoacyl tRNA. After that, EFTU-GTP-aminoacyl tRNA binds to the ribosome.\n4. The GTP hydrolysis and the GDP-EFTU complex release. The EFTS later dissociates the complex. Then, hydrolysis facilitates the attachment of aminoacyl tRNA into the A-site of the ribosome.\n\nPeptidyl transfer or transpeptidation\n\nIn this step, the peptide bond forms between the terminal carboxyl group of the peptide on the P-site and the alpha-amino group of amino acids at the A-site. The enzyme peptidyl transferase catalyzes the reaction. The step does not require GTP and ATP. The tRNA in the P-site becomes uncharged and deacylated, and the dipeptide tRNA is bound to the A-site.\n\nTranslocation\n\nIn this step, the ribosomes move a codon towards the 3′ end of mRNA. The movement shifts the deacylated tRNA from the P-site to E-site. From the E-site, it releases into the cytosol. Then the anticodon of the dipeptidyl tRNA translocate from A-site to P-site. The translocation\u002Fmovement of the ribosome requires EFG and a molecule of GTP. Now, the new codon in the A-site again recognizes the specific aminoacyl tRNA. The elongation step repeats and forms a long chain of polypeptides.\n\n### Termination of polypeptide synthesis\n\n![termination of polypeptide synthesis (translation) - Termination of polypeptide synthesis](\u002Fblogs\u002Ftermination-step-of-translation.png)Figure: Termination of polypeptide synthesis\n\nThe presence of one of the three codons, UAA, UAG, and UGA, signals the termination of polypeptide synthesis. In prokaryotes, the three factors, RF1, RF2, and RF3 recognizes the termination signals. The RF1 recognizes UAG and UAA codons, and RF2 recognizes UGA and UAA codons. The RF3, along with GTP, releases the RF1 and RF2 and dissociates the combined ribosome into its subunits.\n\nWhereas the eRF factor recognizes the stop codons in eukaryotes, and unchanged tRNA expels directly from the P-site.\n\n## Post Translational Modification\n\nThe nascent polypeptide chain undergoes numerous chemical, physical, and biological changes to change into the active protein, termed post-translational modification. The modifications are as follows:\n\n1. **Amino-terminal and carboxy-terminal modification:** The removal of N-formyl methionine in bacteria may occur enzymatically to form the final functional protein. In 50% eukaryotic protein, the amino group in the amino-terminal residue is N-acetylated after translocation.\n\n2. **Loss of signal sequences**: The loss of 15 to 30 residues at the amino-terminal directs the protein to its ultimate destination in the cell. Specific peptides ultimately remove such signal sequences.\n\n3. **Modification of individual amino acid:** ATP enzymatically phosphorylates some proteins’ OH-group of ser, threonine, and tyrosine residues. Casein has many phospho-serine groups that bind to Ca++. So casein provides calcium, phosphate, and amino acids.\n\n4. **Attachment of carbohydrate:** The glucose or carbohydrate group’s attachment to the polypeptide forms the glycoproteins.\n\n5. **Addition of the isoprenyl group:** thioester bond adds the isoprenyl or isoprene group to cysteine residue. The isoprene group helps to anchor the protein in a membrane.\n\n6. **Addition of a prosthetic group:** Prosthetic groups like the heme group are added to form hemoglobin, and the biotin molecule is the added molecule of acetyl CoA carboxylase.\n\n7. **Proteolytic processing:** Sometimes larger inactive proteins trims to form smaller active proteins.\n\n8. Disulfide cross-links form between cysteine residues, which help protect the folded shape of a protein from denaturation in the extracellular environment.\n\n## How to Remember\n\n**Translation = language conversion.** The word says it. Translation converts the nucleotide language (A, U, G, C in codons) into the amino acid language (the protein). If you remember the name, you remember the point.\n\n**The three steps: I, E, T.** **I**nitiation (start), **E**longation (build), **T**ermination (stop). Every protein is made this way: start, build, stop. Activation (\"charging\" the tRNAs) is the preparation before the start.\n\n**tRNA is the adapter.** One end holds an amino acid; the other end (the anticodon) reads the codon. Picture a luggage cart: it carries a specific bag (amino acid) and has a matching ticket (anticodon) for a specific slot (codon). This is how the code is turned into a real amino acid.\n\n**AUG starts, UAA\u002FUAG\u002FUGA stop.** The start codon is AUG (methionine). The three stop codons are UAA, UAG, UGA. A memory phrase for the stops: \"U Are Away \u002F U Are Gone \u002F U Go Away.\"\n\n**A, P, E across the ribosome.** A tRNA arrives at the A site, the growing chain is held at the P site, and the empty tRNA leaves from the E site. Arrive, Peptide, Exit.\n\n## Key exam facts in one table\n\n| Fact | Detail |\n| --- | --- |\n| What translation does | Builds a protein from mRNA (reads codons, joins amino acids) |\n| Where it happens | Ribosome (in the cytoplasm) |\n| Codon | Group of three mRNA bases; codes for one amino acid |\n| Start codon | AUG (methionine) |\n| Stop codons | UAA, UAG, UGA |\n| tRNA role | Adapter: carries an amino acid, reads a codon via its anticodon |\n| Charging enzyme | Aminoacyl-tRNA synthetase (attaches amino acid to tRNA) |\n| Three main steps | Initiation, elongation, termination |\n| Preparation step | Activation (charging the tRNA) |\n| Peptide bond enzyme | Peptidyl transferase (an rRNA ribozyme) |\n| End product | A polypeptide (protein) |\n| First amino acid | Methionine (formyl-methionine in bacteria) |\n\n## Where Students Get Confused\n\n**The end product of translation is a protein, not an amino acid.** Amino acids are the raw material that goes in. Translation joins them into a chain (a polypeptide) that folds into a protein. If a question asks for the end product, the answer is the polypeptide or protein.\n\n**Transcription versus translation.** Transcription copies DNA into mRNA (first step, in the nucleus in eukaryotes). Translation reads mRNA to build a protein (second step, at the ribosome). \"Transcription writes the message; translation reads it.\"\n\n**The ribosome is made of rRNA and protein, not tRNA.** tRNA is a separate delivery molecule that visits the ribosome. A common slip is to say the ribosome contains tRNA. It contains rRNA and ribosomal proteins.\n\n**Codon versus anticodon.** The codon is on the mRNA. The anticodon is on the tRNA. They pair up (codon on the message, anticodon on the adapter). Mixing up which is which is a frequent error.\n\n**Start codon has two jobs.** AUG both signals \"start here\" and codes for methionine. So the first amino acid of a new protein is usually methionine (or formyl-methionine in bacteria), though it is often removed later.\n\n## References\n\n1. Watson JD, Baker TA, Bell SP, Gann A, Levine M, Losick R. *Molecular Biology of the Gene*. 7th ed. Pearson; 2013.\n2. Nelson DL, Cox MM. *Lehninger Principles of Biochemistry*. 8th ed. W.H. Freeman; 2021.\n3. Alberts B, Heald R, Johnson A, et al. *Molecular Biology of the Cell*. 7th ed. W.W. Norton; 2022.\n4. Madigan MT, Bender KS, Buckley DH, Sattley WM, Stahl DA. *Brock Biology of Microorganisms*. 16th ed. Pearson; 2021.",[50,53,56,59,62,65,68,71],{"question":51,"answer":52},"\u003Cp>What is translation in protein synthesis?\u003C\u002Fp>","\u003Cp>Translation is the process by which a cell reads the message in messenger RNA (mRNA) and builds a protein from it. It converts the nucleotide language of mRNA (read in three-base codons) into the amino acid language of a protein. It happens at the ribosome.\u003C\u002Fp>",{"question":54,"answer":55},"\u003Cp>What are the main steps of translation?\u003C\u002Fp>","\u003Cp>The three main steps are initiation (the ribosome assembles on the mRNA at the start codon), elongation (the ribosome moves along the mRNA adding one amino acid per codon), and termination (a stop codon is reached and the finished protein is released). Before these, an activation or charging step attaches each amino acid to its tRNA.\u003C\u002Fp>",{"question":57,"answer":58},"\u003Cp>Where does translation occur?\u003C\u002Fp>","\u003Cp>Translation occurs at the ribosome, in the cytoplasm of the cell. In eukaryotes, ribosomes may be free in the cytoplasm or attached to the rough endoplasmic reticulum.\u003C\u002Fp>",{"question":60,"answer":61},"\u003Cp>What is the end product of translation?\u003C\u002Fp>","\u003Cp>The end product is a polypeptide, which folds into a protein. The amino acids are the raw material; translation joins them into the finished chain. The end product is not a single amino acid.\u003C\u002Fp>",{"question":63,"answer":64},"\u003Cp>What is the role of tRNA in translation?\u003C\u002Fp>","\u003Cp>tRNA is an adapter molecule. One end carries a specific amino acid, and the other end has a three-base anticodon that matches a codon on the mRNA. This lets the tRNA bring the correct amino acid to the ribosome for each codon.\u003C\u002Fp>",{"question":66,"answer":67},"\u003Cp>What is the start codon and what are the stop codons?\u003C\u002Fp>","\u003Cp>The start codon is AUG, which also codes for methionine. The three stop codons are UAA, UAG, and UGA. Stop codons do not code for an amino acid; they signal the end of translation.\u003C\u002Fp>",{"question":69,"answer":70},"\u003Cp>Which enzyme attaches an amino acid to its tRNA?\u003C\u002Fp>","\u003Cp>Aminoacyl-tRNA synthetase. This enzyme charges each tRNA with its correct amino acid, using energy from ATP, during the activation step.\u003C\u002Fp>",{"question":72,"answer":73},"\u003Cp>What is the difference between transcription and translation?\u003C\u002Fp>","\u003Cp>Transcription copies a gene from DNA into mRNA and happens first (in the nucleus in eukaryotes). Translation reads that mRNA to build a protein and happens second, at the ribosome. Transcription makes the message; translation reads it.\u003C\u002Fp>",[75],"genetic-code",[77],{"slug":78,"title":79,"description":80,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":81,"lastUpdatedDate":45,"draft":46,"category":47,"image":42,"faq":82,"tags":107},"ribosomes-types-structure-and-function","Ribosome: Types, Structure, and Function","\u003Cp>Ribosomes are the cell's protein factories. Learn the two types (70S and 80S), their structure and composition, what they do, and why the difference lets antibiotics kill bacteria safely.\u003C\u002Fp>","2023-10-29",[83,86,89,92,95,98,101,104],{"question":84,"answer":85},"\u003Cp>What is a ribosome?\u003C\u002Fp>","\u003Cp>A ribosome is the cell structure that makes proteins. It reads the instructions in messenger RNA and joins amino acids together in the right order. It is often called the protein factory of the cell.\u003C\u002Fp>",{"question":87,"answer":88},"\u003Cp>What are the two types of ribosomes?\u003C\u002Fp>","\u003Cp>The 70S ribosome, found in bacteria (and in mitochondria and chloroplasts), and the 80S ribosome, found in the cytoplasm of eukaryotic cells such as plant and animal cells. The 70S is smaller; the 80S is larger.\u003C\u002Fp>",{"question":90,"answer":91},"\u003Cp>What are the subunits of the 70S and 80S ribosomes?\u003C\u002Fp>","\u003Cp>The 70S ribosome is made of a 50S large subunit and a 30S small subunit. The 80S ribosome is made of a 60S large subunit and a 40S small subunit.\u003C\u002Fp>",{"question":93,"answer":94},"\u003Cp>Why do the ribosome subunit numbers not add up?\u003C\u002Fp>","\u003Cp>Because the S (Svedberg) unit measures how fast a particle settles when spun, not its weight. Settling speed depends on shape and density as well as size, so the values are not additive. That is why a 50S and a 30S subunit form a 70S ribosome, not an 80S.\u003C\u002Fp>",{"question":96,"answer":97},"\u003Cp>What is the chemical composition of a ribosome?\u003C\u002Fp>","\u003Cp>A ribosome is made of ribosomal RNA (rRNA) and proteins. In the bacterial 70S ribosome, rRNA makes up about two-thirds and protein about one-third. In the 80S ribosome the two are closer to equal.\u003C\u002Fp>",{"question":99,"answer":100},"\u003Cp>What is the function of the ribosome?\u003C\u002Fp>","\u003Cp>The ribosome carries out protein synthesis. It holds the mRNA and tRNAs in place and, using an rRNA enzyme called peptidyl transferase, joins amino acids into a protein chain.\u003C\u002Fp>",{"question":102,"answer":103},"\u003Cp>Why do antibiotics target ribosomes?\u003C\u002Fp>","\u003Cp>Because bacterial ribosomes (70S) are different from human ribosomes (80S). Many antibiotics, such as aminoglycosides, tetracyclines, and macrolides, jam the bacterial 70S ribosome and stop the bacterium making proteins, while leaving the human 80S ribosome largely untouched. This difference makes the drugs work safely.\u003C\u002Fp>",{"question":105,"answer":106},"\u003Cp>Where are ribosomes found in the cell?\u003C\u002Fp>","\u003Cp>In bacteria, ribosomes float freely in the cytoplasm. In eukaryotic cells, they are found free in the cytoplasm, attached to the rough endoplasmic reticulum, and also inside mitochondria and chloroplasts.\u003C\u002Fp>",[75],{"enabled":109,"threads":110,"total":111},true,[],0,[113,120,126,133,139,144,150,155,161,164,171],{"slug":114,"name":115,"description":116,"image":117,"body":118,"postCount":119},"acharya-tankeshwar","Acharya Tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",468,{"slug":121,"name":43,"description":122,"image":123,"body":124,"postCount":125},"ashma-shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",78,{"slug":127,"name":128,"description":129,"image":130,"body":131,"postCount":132},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsushmita-baniya-1.png","Sushmita Baniya holds an M.Sc. in Medical Microbiology from Tribhuvan University (National College), with a research focus in Genetics and Molecular Biology. She is actively involved in teaching and research in the field of microbiology.",26,{"slug":134,"name":135,"description":129,"image":136,"body":137,"postCount":138},"samikshya-acharya","Samikshya Acharya","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsamikshya-acharya.jpeg","Samikshya Sharma completed her postgraduate studies in Medical Microbiology at the Central Department of Microbiology, Tribhuvan University, Nepal. She contributes to Microbeonline with the goal of making foundational and clinical microbiology concepts clear and useful for students in medical, laboratory science, and allied health programs.",20,{"slug":140,"name":141,"description":129,"image":42,"body":142,"postCount":143},"alisha-tripathi","Alisha Tripathi","Alisha Tripathi holds an M.Sc. in Medical Microbiology from National College, Tribhuvan University. With over a year of teaching experience, her academic interests span Molecular Biology, Immunology, and Genetics.",6,{"slug":145,"name":146,"description":147,"image":42,"body":148,"postCount":149},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor","Aastha Shrestha is a Biotechnology graduate with an M.Sc. from National College, Tribhuvan University. Her academic interests center on Molecular Biology and Immunology; two fields that are increasingly converging in modern diagnostic and clinical microbiology. \n\nShe contributes to Microbeonline with the goal of making complex concepts in these areas approachable and exam-relevant for students across medical, biotechnology, and laboratory science programs.",9,{"slug":151,"name":152,"description":153,"image":42,"body":42,"postCount":154},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":156,"name":157,"description":129,"image":158,"body":159,"postCount":160},"srijana-khanal","Srijana Khanal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsrijana-khanal-1.png","Srijana Khanal is a microbiology educator with nearly a decade of teaching experience, including her role as faculty in the Microbiology Department at National College, NIST. \n\nHer time in the classroom has given her a clear sense of where students struggle and what explanations actually work, a perspective that directly shapes how she writes.\n\nHer academic interests span Immunology, Genetics, Basic Sciences, and Research Methodology, and she brings the same rigor to her writing that she brought to teaching. Alongside academic writing, she has a passion for creative writing -- an instinct that shows in her ability to make dense scientific material readable without sacrificing accuracy.\n\nShe contributes to Microbeonline to extend her teaching reach beyond the classroom, helping medical and laboratory science students across the region build a stronger foundation in microbiology.",17,{"slug":162,"name":163,"description":153,"image":42,"body":42,"postCount":154},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":165,"name":166,"description":167,"image":168,"body":169,"postCount":170},"nisha-rijal","Nisha Rijal","Microbiologist and AMR Specialist Kathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fnisha-rijal-1.png","Nisha Rijal is a microbiologist with nearly 15 years of frontline diagnostic and surveillance experience at the National Public Health Laboratory (NPHL), national reference laboratory under the Department of Health Services, Nepal. She currently works as an AMR Support Officer at the World Health Organization (WHO), Nepal, where her work focuses on strengthening antimicrobial resistance surveillance systems and translating AMR data into actionable public health response.\n\nHer research, published in peer-reviewed journals and cited over 220 times, spans some of the most clinically significant infectious disease challenges in Nepal and South Asia: antimicrobial resistance trends in *Vibrio cholerae* across an 11-year national surveillance dataset, sero-epidemiology of scrub typhus in patients with acute febrile illness, lower respiratory tract infections in HIV-positive patients, and gonococcal resistance surveillance. She was a contributor to Nepal's National Antimicrobial Resistance Containment Action Plan, a foundational policy document for AMR governance in Nepal. You can find list of [Nisha Rijal's article here in Google Scholar.](https:\u002F\u002Fscholar.google.com\u002Fcitations?user=N-Ruq54AAAAJ&hl=en)\n\nThis depth of experience is visible in her writing at Microbeonline. Her 53 published articles cover bacteriology, parasitology, mycology, immunology, and laboratory techniques, and are consistently among the most detailed and clinically grounded content on the site. She brings to every article the same standard that national reference laboratory work demands: methodological precision, awareness of real diagnostic constraints, and an understanding of what results actually mean for patient care in resource-limited settings.\n\nHer areas of particular expertise include antimicrobial susceptibility testing and resistance mechanism detection, quality assurance in clinical microbiology, and laboratory-based infectious disease surveillance.\n\n---\n\n*Nisha Rijal contributes to Microbeonline in a personal capacity. Her views and writing do not represent the positions of the World Health Organization or any other institution.*",54,{"slug":172,"name":173,"description":174,"image":175,"body":176,"postCount":154},"padma-shrestha","Padma Shrestha","Author","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fpadma-shrestha.png","Padma Shrestha is from Kathmandu, Nepal. She has completed Masters degree in Medical microbiology from Tribhuvan University. She has great interest in Microbiology and Molecular Biology.",[178,185,191,196,201,206,210,214,218,223,227,232,236,241,246,250,254,258,263,268,272,276,280,285,289,293,297,301,306,311,315,319,323,327,331,335,339,343,347,351,355,359,363,367,371,375,379,383,388,392,396,400,404,408,412,416,420,424,428,432,436,440,444,448,452,456,459,463,466,470],{"slug":179,"name":180,"description":181,"image":182,"body":183,"postCount":184},"gram-negative-cocci","Gram-Negative Cocci and Coccobacilli","Neisseria, Moraxella, Haemophilus and related gram-negative coccal organisms","https:\u002F\u002Fassets.microbeonline.com\u002Ftags\u002Fgram-negative-cocci.png","# Gram Negative Cocci\n\nNeisseria gonorrhoeae, Neisseria meningitides, Moraxella catarrhalis, and other Neisseria spp. are clinically relevant gram-negative cocci.\n\nN. gonorrhoeae is the leading cause of sexually transmitted disease whereas N. meningitides is a leading cause of fatal bacterial meningitis.",14,{"slug":186,"name":187,"description":188,"image":42,"body":189,"postCount":190},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":192,"name":193,"description":194,"image":42,"body":42,"postCount":195},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",11,{"slug":197,"name":198,"description":199,"image":42,"body":42,"postCount":200},"gram-negative-rods","Gram-Negative Rods (Other than Enterobacteriaceae)","\u003Cp>Gram negative rods other than members of Enterobacteriaceae family such as  Pseudomonas, Acinetobacter and related organisms\u003C\u002Fp>",5,{"slug":202,"name":203,"description":204,"image":42,"body":42,"postCount":205},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":207,"name":208,"description":209,"image":42,"body":42,"postCount":195},"mycobacteria","Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":211,"name":212,"description":213,"image":42,"body":42,"postCount":195},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":215,"name":216,"description":217,"image":42,"body":42,"postCount":190},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":219,"name":220,"description":221,"image":42,"body":42,"postCount":222},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":224,"name":225,"description":226,"image":42,"body":42,"postCount":184},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":228,"name":229,"description":230,"image":42,"body":42,"postCount":231},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",21,{"slug":233,"name":234,"description":235,"image":42,"body":42,"postCount":205},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":237,"name":238,"description":239,"image":42,"body":42,"postCount":240},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":242,"name":243,"description":244,"image":42,"body":42,"postCount":245},"specimen-collection-transport","Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":247,"name":248,"description":249,"image":42,"body":42,"postCount":231},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",{"slug":251,"name":252,"description":42,"image":42,"body":253,"postCount":143},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":255,"name":256,"description":42,"image":42,"body":257,"postCount":240},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":259,"name":260,"description":261,"image":42,"body":262,"postCount":222},"electrophoresis","Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":264,"name":265,"description":266,"image":42,"body":267,"postCount":143},"pcr-techniques","PCR Techniques","Information about various types of Polymerase Chain Reaction Techniques ","More detailed information about various types of Polymerase Chain Reaction Techniques ",{"slug":269,"name":270,"description":271,"image":42,"body":42,"postCount":143},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":273,"name":274,"description":275,"image":42,"body":42,"postCount":143},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":277,"name":278,"description":279,"image":42,"body":42,"postCount":143},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":281,"name":282,"description":283,"image":42,"body":42,"postCount":284},"immunoassays","Immunoassays","You will get information about all the diagnostic tests that rely on the specific binding between an antigen and an antibody to detect or quantify a substance.",19,{"slug":286,"name":287,"description":288,"image":42,"body":42,"postCount":222},"biosafety-levels","Biosafety levels ","Articles related to Biosafety Levels",{"slug":290,"name":291,"description":292,"image":42,"body":42,"postCount":200},"environmental-factors","Environmental Factors ","In this case we are talking about growth requirements of microorganisms with deep dive in environmental factors that affect the growth. ",{"slug":294,"name":295,"description":296,"image":42,"body":42,"postCount":143},"pipette","Pipette","Posts related with Pipette. ",{"slug":298,"name":299,"description":300,"image":42,"body":42,"postCount":205},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":302,"name":303,"description":304,"image":42,"body":42,"postCount":305},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":307,"name":308,"description":309,"image":42,"body":42,"postCount":310},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":312,"name":313,"description":314,"image":42,"body":42,"postCount":200},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",{"slug":316,"name":317,"description":318,"image":42,"body":42,"postCount":205},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":320,"name":321,"description":322,"image":42,"body":42,"postCount":149},"microbial-curiosities","Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":324,"name":325,"description":326,"image":42,"body":42,"postCount":231},"bacterial-culture-media","Bacterial Culture Media","Posts related to Bacterial Culture Media. ",{"slug":328,"name":329,"description":330,"image":42,"body":42,"postCount":143},"fungal-culture-media","Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":332,"name":333,"description":334,"image":42,"body":42,"postCount":200},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":336,"name":337,"description":338,"image":42,"body":42,"postCount":240},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":340,"name":341,"description":342,"image":42,"body":42,"postCount":305},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":344,"name":345,"description":346,"image":42,"body":42,"postCount":310},"dimorphic-fungi","Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":348,"name":349,"description":350,"image":42,"body":42,"postCount":222},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":352,"name":353,"description":354,"image":42,"body":42,"postCount":200},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":356,"name":357,"description":358,"image":42,"body":42,"postCount":149},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":360,"name":361,"description":362,"image":42,"body":42,"postCount":222},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":364,"name":365,"description":42,"image":42,"body":42,"postCount":366},"haemophilus","Haemophilus",3,{"slug":368,"name":369,"description":370,"image":42,"body":42,"postCount":310},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":372,"name":373,"description":374,"image":42,"body":42,"postCount":190},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",{"slug":376,"name":377,"description":378,"image":42,"body":42,"postCount":184},"fungal-diagnostics","Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":380,"name":381,"description":382,"image":42,"body":42,"postCount":200},"laboratory-storage-and-preservation","Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":384,"name":385,"description":386,"image":42,"body":387,"postCount":143},"laboratory-heating-equipment","Laboratory Heating Equipment","A guide to laboratory heating equipment, including hot plates, water baths, Bunsen burners, incubators, and dry baths, and how to choose the right one for each task.","Laboratory heating equipment covers the instruments that warm, melt, incubate, or sterilize samples and media in a microbiology laboratory. Each one delivers heat differently. \n\nA hot plate gives high, direct, dry heat; a water bath gives gentle, even, wet heat up to about 100°C; a Bunsen burner gives an open flame for rapid, very high heat; an incubator holds cultures at a steady temperature over hours or days; and a dry bath heats small tubes without water. Choosing the right one depends on the temperature you need, how precise it must be, and whether the sample can tolerate direct or open-flame heat.\n\nThe articles below cover each piece of heating equipment in detail, including its parts, working principle, uses, and the mistakes that most often go wrong at the bench.",{"slug":389,"name":390,"description":391,"image":42,"body":42,"postCount":205},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":393,"name":394,"description":395,"image":42,"body":42,"postCount":143},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":397,"name":398,"description":399,"image":42,"body":42,"postCount":143},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":401,"name":402,"description":403,"image":42,"body":42,"postCount":154},"tests-for-gram-positive-cocci","Biochemical Tests for Gram Positive Cocci","This is the lists of Biochemical Tests that are used for Gram Positive Cocci. ",{"slug":405,"name":406,"description":407,"image":42,"body":42,"postCount":240},"bacterial-staining-technique","Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":409,"name":410,"description":411,"image":42,"body":42,"postCount":138},"enzyme-tests","Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":413,"name":414,"description":415,"image":42,"body":42,"postCount":195},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",{"slug":417,"name":418,"description":419,"image":42,"body":42,"postCount":200},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":421,"name":422,"description":423,"image":42,"body":42,"postCount":310},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":425,"name":426,"description":427,"image":42,"body":42,"postCount":205},"substrate-utilization","Substrate Utilization","\u003Cp>The test in which a non-sugar carbon\u002Fnitrogen source is used or degraded (citrate, malonate, decarboxylases, indole, PAD).\u003C\u002Fp>",{"slug":429,"name":430,"description":431,"image":42,"body":42,"postCount":366},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":433,"name":434,"description":435,"image":42,"body":42,"postCount":200},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":437,"name":438,"description":439,"image":42,"body":42,"postCount":222},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":441,"name":442,"description":443,"image":42,"body":42,"postCount":310},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":445,"name":446,"description":447,"image":42,"body":42,"postCount":200},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":449,"name":450,"description":451,"image":42,"body":42,"postCount":222},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":453,"name":454,"description":455,"image":42,"body":42,"postCount":143},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":75,"name":457,"description":458,"image":42,"body":42,"postCount":222},"Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":460,"name":461,"description":462,"image":42,"body":42,"postCount":200},"molecular-technique","Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":464,"name":465,"description":42,"image":42,"body":42,"postCount":154},"colorimetric-assay","Colorimetric Assay ",{"slug":467,"name":468,"description":469,"image":42,"body":42,"postCount":200},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":471,"name":472,"description":42,"image":42,"body":42,"postCount":366},"blood-and-immune-cells","Blood and Immune Cells"]