Translation

"Describe the process of translation in protein synthesis, including initiation, elongation, and termination."


Here are two definitions that mean the same thing because I'm annoying like that:

Translation is the process where the sequence of codons formed during transcription becomes the order of amino acids in a polypeptide.

Process by which the sequence of codons in mRNA dictates the sequence of amino acids in a polypeptide.


Where transcription copies the sequence of bases from the DNA string to form mRNA, translation translates these base codons to become amino acid polypeptides.


During translation, the sequence of codons on the mRNA show the amino acids which order to go in to create their polypeptide


Three Steps of translation: 

This is my incomplete Karla ramble:
 
We begin with our mRNA, hanging out in the cytoplasm. It left the nucleus after it had been transcribed and processed (Checked for errors). Here it comes into contact with ribosomal subunits. Two parts of a ribosome (subunits) surround this mRNA, a smaller one and a larger one. The smaller one fuses to the mRNA and the larger one fuses to the smaller one. the mRNA is being fed through this ribosome.

Once surrounded by ribosomes, the mRNA comes into contact with tRNA. tRNA comes bearing an amino acid complementary to the codons on the mRNA. Two tRNA enter the ribosome at a time.  The first tRNA comes in and pairs to the codons. The second tRNA enters the ribosome and receives the peptide from the first tRNA, which leaves the ribosome and makes room for another tRNA amino acid complex to enter the ribosome. Like this, the chain of amino acids grows like a tail, out of the ribosome, each tRNA pairing with a codon and giving its amino acid to the growing chain and leaving to make room for another tRNA amino acid complex to enter.

When the ribosome comes to the stop codon on the mRNA, the ribosome dissociates and falls off the mRNA molecule and is done.

The proper definition of translation:

Three steps and one pre-step to describe rRNA

0. rRNA, also called structural RNA is formed in the nucleolus. There, it join with proteins (made in the cytoplasm) to be a ribosomal subunit. it travels out to the cytoplasm to join just as protein synthesis starts. Each ribosomal sub unit contains proteins and rRNA. One of the proteins in rRNA is the enzyme that joins amino acids together with a peptide bond.

1. Initiation: mRna binds to the smaller of the two ribosomal subunits that join and surround it. 

2. Elongation: One amino acid at a time, the poly peptide begins to form and lengthen.

The ribosome has room for two tRNAs to work in it. The first tRNA goes into the ribosome bearing an amino acid. The tRNA has the anti codon to the codon on the mRNA. This first tRNA gives its peptide to the second tRNA entering the ribosome. In this way, the chain grows and forms the primary structure of the protein molecule. Secondary and tertiary structure come to be after termination.

 3. Termination of synthesis: The ribosome encounters a stop codon on the mRNA. There is no tRNA for this and the ribosome dissociates and falls off the mRNA molecule.

 a polyribosome can sometimes form on a mRNA and form several of the same polypeptides can be formed at the same time.