Protein
PROTEIN TRANSLATION
1. Initiation Translation
To begin translation: large and small ribosomal subunit, along with the initiating tRNA, assembles onto the mRNA
2. Translation Elongation
The next amino acyl-tRNA enters the ribosome at the A site
The amino acid at the P site is transferred to the tRNA at the A site. The ribosome moves one codon farther along the mRNA, releasing the empty tRNA through the E (exit) site.
The A site is free for the next incoming RNA.
The cycle is repeated as the ribosome travels along the mRNA, resulting a growing polypeptide chain.
3. Termination
- is triggered by a stop codon (recognized by release factors which help release the fully synthesized polypeptide chain from the ribosome)
- the ribosome separates from the mRNA
The first amino acid is always the same: AUG, Met.
Entire Translation Process o In translation, the sequence of bases in the mRNA is converted to an amino acid sequence in a protein o Each amino acid is specified by three bases (a codon) in the mRNA, according to a nearly universal genetic code o Ribosomes catalyze translation of the mRNA sequence into protein o inside the ribosomes, mRNA are translated to proteins via intermediary molecules - tRNA o tRNA carry an amino acid and have three-base-pair anti-codon, which binds to an mRNA codon. o the amino acid carried by the tRNA is then added to the growing protein via formation of peptide bond
Moving down to the mRNA
Translocation:
occurs when the ribosome moves down the mRNA in the 5' - 3' direction, moves the empty tRNA into the E site, moves the tRNA containing the growing polypeptide into the P site, and opens the A site to expose a new mRNA codon
The three steps in elongation repeat down the length of the mRNA
1. entrance of amino acid containing tRNA
2. peptide bond formation
3. translocation
Lecture #16 October 12/2012
Protein Translation
- 1st step of translation: begins when a large and small ribosomal subunit, along with the
1. Initiation Translation
To begin translation: large and small ribosomal subunit, along with the initiating tRNA, assembles onto the mRNA
2. Translation Elongation
The next amino acyl-tRNA enters the ribosome at the A site
The amino acid at the P site is transferred to the tRNA at the A site. The ribosome moves one codon farther along the mRNA, releasing the empty tRNA through the E (exit) site.
The A site is free for the next incoming RNA.
The cycle is repeated as the ribosome travels along the mRNA, resulting a growing polypeptide chain.
3. Termination
- is triggered by a stop codon (recognized by release factors which help release the fully synthesized polypeptide chain from the ribosome)
- the ribosome separates from the mRNA
The first amino acid is always the same: AUG, Met.
Entire Translation Process o In translation, the sequence of bases in the mRNA is converted to an amino acid sequence in a protein o Each amino acid is specified by three bases (a codon) in the mRNA, according to a nearly universal genetic code o Ribosomes catalyze translation of the mRNA sequence into protein o inside the ribosomes, mRNA are translated to proteins via intermediary molecules - tRNA o tRNA carry an amino acid and have three-base-pair anti-codon, which binds to an mRNA codon. o the amino acid carried by the tRNA is then added to the growing protein via formation of peptide bond
Moving down to the mRNA
Translocation:
occurs when the ribosome moves down the mRNA in the 5' - 3' direction, moves the empty tRNA into the E site, moves the tRNA containing the growing polypeptide into the P site, and opens the A site to expose a new mRNA codon
The three steps in elongation repeat down the length of the mRNA
1. entrance of amino acid containing tRNA
2. peptide bond formation
3. translocation
Lecture #16 October 12/2012
Protein Translation
- 1st step of translation: begins when a large and small ribosomal subunit, along with the