Translation: Advanced Look --> 2.) Initiation

Initiation is the second stage in translation. It is here that the ribosome attaches to the strand of mRNA, and the first charged tRNA molecule appears. Clicking on each of the thumbnail images will bring up a larger, labeled version of the described scene.

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	To begin initiation, the small subunit of a ribosome attaches to the mRNA. The area where it first attaches is an untranslated section of mRNA located near the cap.
	The small subunit then moves along the mRNA until it reaches the first readable codon. This codon always codes for the amino acid methionine.
	The tRNA molecules are the next to enter. These charged molecules of RNA bring the amino acids to the ribosome.
	Each tRNA has a triplet coding sequence that corresponds with the amino acid it carries along.
	The triplet sequence of the tRNA is complementary to the triplet codon sequence in the mRNA.
	Each triplet codon sequence in the mRNA and the tRNA corresponds to a specific amino acid.
	After the first tRNA moves into place, the large subunit of the ribosome attaches to the small subunit.
	The complete ribosome consists of two sites: petidyl (left) and aminoacyl (right).

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