How does the ribosome know where to start translation on the mRNA?

(1) Translation begins when a ribosome (gray) docks on a start codon (red) of an mRNA molecule in the cytoplasm. (2) Next, tRNA molecules attached to amino acids (spheres) dock at the corresponding triplet codon sequence on the mRNA molecule.

What does the ribosome look for to know to start translation?

In initiation, the ribosome assembles around the mRNA to be read and the first tRNA (carrying the amino acid methionine, which matches the start codon, AUG). This setup, called the initiation complex, is needed in order for translation to get started.

What does the ribosome do when it is done translating the first codon?

The ribosome moves forward on the mRNA, codon by codon, as it is read and translated into a polypeptide (protein chain). Then, once translation is finished, the two pieces come apart again and can be reused.

How is RNA read by the ribosome?

Ribosomes read the nucleotide sequence of a messenger RNA (mRNA) into a protein sequence, using the genetic code. Each ribosome can bind one mRNA and up to three tRNAs. Each new amino acid is brought into the ribosome as an aminoacyl-tRNA, by elongation factor EF-Tu.

What happens during initiation of translation?

Initiation of translation occurs when mRNA, tRNA, and an amino acid meet up inside the ribosome. Once translation has begun, it continues down the line as mRNA shifts along through the ribosome. Each new codon matches with a new tRNA anticodon, bringing in a new amino acid to lengthen the chain.

What does the ribosome read?

The ribosome reads the sequence of the messenger RNA (mRNA) and, using the genetic code, translates the sequence of RNA bases into a sequence of amino acids.

What happens to the ribosomes during translation?

During translation, the two subunits come together around a mRNA molecule, forming a complete ribosome. The ribosome moves forward on the mRNA, codon by codon, as it is read and translated into a polypeptide (protein chain). Then, once translation is finished, the two pieces come apart again and can be reused.

How does the ribosome work with mRNA?

The ribosome starts matching tRNA anticodon sequences to the mRNA codon sequence. Each time a new tRNA comes into the ribosome, the amino acid that it was carrying gets added to the elongating polypeptide chain. The ribosome continues until it hits a stop sequence, then it releases the polypeptide and the mRNA.

What are the steps in translation of mRNA?

The steps in translation are: The ribosome binds to mRNA at a specific area. The ribosome starts matching tRNA anticodon sequences to the mRNA codon sequence.

What is the difference between ribosomes and tRNAs?

Ribosomes provide a structure in which translation can take place. They also catalyze the reaction that links amino acids to make a new protein. tRNAs ( transfer RNAs) carry amino acids to the ribosome. They act as “bridges,” matching a codon in an mRNA with the amino acid it codes for. Here, we’ll take a closer look at ribosomes and tRNAs.