What is translation? Why is it important (in terms of this Anthropology class)? [translation/protein synthesis]

Expert Solution

Translation

It refers to the polymerisation of amino acids to form a polypeptide. The order and sequence of amin acids are defined by the sequence of bases in the mRNA.

The cellular factory responsible for synthesising protens is the ribosome. The ribosome consits of structurall RNAs and atbout 80 different proteins. In its inactive state,. it exists as two sub units, a large subunit and a small sub unit. Ribosomes have two sites for binding amino acyl tRNA, P-site (peptidyl site) and A-site (aminoacy). When the small subunit encounters an mRNA, the process of translation of the mRNA to protien begins.

The steps of transiation mechanism are:

(a) Activation of amino acids:

In the presence of enzyme aminoacyl - tRNA synthetase(E), specifc amino acid (AA) bind with ATP.
AA1 + ATP -----> AA1-AMP-E1 complex + PPi

(b) Charging of tRNA :

The AA1, AMP-E1, complex reacts with specifc tRNA. Thus, amino acid is transferred to tRNA as a result, the enzyme and AMP are liberated. It is also called as aminoacylation of tRNA
AA, +AMP-E, complex+ tRNA一一>AA1 -tRNA, +AMP+E1

(c) Formation of polypeptide chain : It completes in three steps :
(1) Chain intiation: It requires 3 intiation factors in prokaryotes and 9 initiation factors in eukaryotes.
*Binding of mRNA with smaller subunit of ribosomes (30S/40S)
30S +mRNA-30S-mRNA complex
In eukaryotes, there is formation of 40S-mRNA complex.
*Binding of 30S-mRNA with tRNA non-formylated methionine is attached with tRNA in eukaryotes and formylated in prokaryotes.
30S-mRNA + tRNA---30S-mRNA-tRNA,
* Attachment of larger subunit of ribosome. It is 50S in prokaryotes & 60S in eukaryotes.

2)Chain elongation :

After the formation of complete ribosome -mRNA-tRNA complex, an aminoacyl acceptor site (A-site) is established next to the P-site. It exposes mRNA codon next to the intiation codon. A new aminoacyl tRNA complex reaches the A-site and forms codon - anticodon bonding. This requires elongaton factor and energy ie., GTP. A peptide bond is formed between COOH group of frst amino acid (methionine) and NH2 group of second amino acid. If two charged tRNAs are close enough the formation of peptide bond between them would be favoured energetically. The presence of a catalyst would enhance the rate of peptide bond formation. It is catalysed by enzymei peptidy transferase (a type of ribozyme -catalytic RNA i.e., 23S rRNA in bacteria and 28 SrRNA in eukaryotes). The elongation factors are required in this process. Translocation is movement of ribosome on mRNA. The ribosome move from codon to codon along the mRNA. Amino acids are added one by one, translated into polypeptide sequences dictated by DNA and represented I by mRNA.

A translational unit in mRNA is the sequence of RNA that is flanked by the start codon (AUG) and the stop codon and codes for a polypeptide. An mRNA also has some additional sequences that are not translated and are referred as untranslated regions (UTRs). The UIRs are present at both 5'-end before start codon and 3'end after stop codon. They are required for efficient translation
process.

(3) Chain termination: the termination of polypeptide is signalled by one of the three termination codon (UAA, UAG, UGA). A GTP - dependent factor known as release factor is associated with termination codon.

gladiator answered 6 months ago

Transcription is the process of RNA synthesis. Translation is the cytoplasmic process of protein synthesis. Both processes...

Transcription is the process of RNA synthesis. Translation is the cytoplasmic process of protein synthesis. Both processes can be divided into three stages, Initiation, Elongation, and Termination. For each of the events listed below write which process it occurs in (either transcription or translation) and in which stage the event occurs (initiation, elongation, termination). Release factor binds to the stop codon in the amino acyl site and cuts away the protein from the transfer RNA. Transfer RNA anticodons bind to the messenger...

Transcription is the process of RNA synthesis. Translation is the cytoplasmic process of protein synthesis. Both processes can...

Transcription is the process of RNA synthesis. Translation is the cytoplasmic process of protein synthesis. Both processes can be divided into three stages, Initiation, Elongation, and Termination. For each of the events listed below write which process it occurs in (either transcription or translation) and in which stage the event occurs (initiation, elongation, termination). a. Peptidyl transferase moves the peptide from the transfer RNA in the peptidyl site to the transfer RNA in the amino acyl site. b. RNA polymerase binds to the...

put the following processes of protein synthesis translation steps in the correct order : A- the...

put the following processes of protein synthesis translation steps in the correct order : A- the next aa2-tRNA attach to the second codon on mRNA located in A site B- then large ribosomal subunit binds the small ribosomal subunit forming an active ribosome C- the ribosome breaks down and the mRNA dissociates and protein is released D- the ribosome small subunit binding to the mRNA F- the first amino acid moves to exit site and leaves the ribosome G- ribosome...

Briefly discuss two mechanisms of post-translation modification of protein synthesis.

During protein synthesis, does translation stop when the signal peptide is synthesized or does translation stop...

During protein synthesis, does translation stop when the signal peptide is synthesized or does translation stop when the SRP (signal receptor particles) bind to the signal peptides -- assuming it's being sent to the endomembrane system?

What is protein synthesis?

Question 2: Translation is another name for protein synthesis. There are three steps that take place...

Question 2: Translation is another name for protein synthesis. There are three steps that take place repeatedly during elongation. a) Give the name and a short description of what happens during the first step of elongation during translation? b) Give the name and a short description of what happens during the second step of elongation during translation? C) Give the name and a short description of what happens during the third step of elongation during translation? Please help! Thanks

Question 3a: Translation is another name for protein synthesis. How does the ribosome know that it...

Question 3a: Translation is another name for protein synthesis. How does the ribosome know that it should terminate translation? Describe briefly what happens to terminate translation. Question 3b: i) What does it mean when someone says that a mutation is cis-acting? ii) What would it mean if someone said that a mutation is trans-acting?

Translation can be considered to have three phases or steps: initiation, protein synthesis, and termination. Please...

Translation can be considered to have three phases or steps: initiation, protein synthesis, and termination. Please give a detailed summary of the factors and molecules involved with each step and, where appropriate, compare/contrast the differences between prokaryotic and eukaryotic translation.

Complete the following questions. Illustrates the process of DNA transcription, translation, and protein synthesis. 1. The stages...

Complete the following questions. Illustrates the process of DNA transcription, translation, and protein synthesis. 1. The stages of transcription are initiation, elongation, and termination. Draw a representation of each of these stages . Be sure to include the names of important enzymes and locations. 2. Once mRNA is created through transcription, it is often processed. Explain how mRNA can be processed. Include the names of important enzymes or structures. 3. Translation is how mRNA gets used to create the peptide sequence. Draw what...

Question