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Translation. PROTEIN SYNTHESIS. 4 Components used in Translation. mRNA - the message to be translated into protein. Amino acids - the building blocks that are linked together to form the protein. Ribosomes - the “machines” that carry out translation.
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Translation PROTEIN SYNTHESIS
4 Components used in Translation • mRNA- the message to be translated into protein. • Amino acids- the building blocks that are linked together to form the protein. • Ribosomes- the “machines” that carry out translation.
tRNA(transfer RNA)- brings an amino acid to the mRNA and ribosome. • One end of a tRNA molecule has an anticodon that complements with an mRNA codon. • The other end has a specific amino acid. • A tRNA molecule with a particular anticodon always carries the same type of amino acid.
How does translation occur? • The ribosome binds to the mRNA molecule. • The tRNA with the anticodon that complements the first codon on the mRNA binds to the first site on the ribosome. • Another tRNA with the anticodon that complements the second codon on the mRNA binds to the second site on the ribosome.
A peptide bond forms between the first two amino acids. • The first tRNA leaves, and the ribosome moves along the mRNA to the next codon. • The next tRNA brings in the next amino acid, and a peptide bond is formed between this amino acid and the growing amino acid chain. • The process continues with the ribosome moving along the mRNA molecule and the amino acids linking together until a STOP codon is reached.
Transcription and translationURLs • http://www.lpscience.fatcow.com/jwanamaker/animations/Protein%20Synthesis%20-%20long.html
CODONS mRNA nucleotides are translated in groups of 3 called codons. AUGCACUGCAGUCGAUGA
Each codon codes for a specific amino acid. 20 different amino acids can be used in different combinations to form a protein. For example: mRNA codonamino acid AAU asparagine CGC arginine GGG glycine
Amino Acid sequence determines the 3-D protein shape • Interactions between amino acids cause folding and bending of the chain Examples: • positive (+) and negative (-) parts of amino acids are attracted to each other. • hydrophobic regions are attracted to each other • Folding http://www.stolaf.edu/people/giannini/flashanimat/proteins/hydrophobic%20force.swf • Structure levels http://www.stolaf.edu/people/giannini/flashanimat/proteins/protein structure.swf
How is the amino acid sequence determined? • The mRNA • Each codon is a code for one amino acid DNA sequence: T A C C G A G A T T C A mRNA sequence: A U GG C UC U AA G U amino acid sequence: Met -- Ala -- Leu -- Ser
Your turn to practice • DNA Bingo • Translation exercise (Find the secret message) • Genes to proteins-practice worksheet. • or • Complete the “Translation Practice” worksheet