Translation, Assmebling a polypeptide.

Also, little note about splicing: the introns are removed because they would interfere with translation. 

Translation:

1. A ribosome attatches to the start codon on the mRNA. 
2. tRNA, which has an amino acid on one end, and an anticodon on the other. The anti codon in complimentary to the mRNA and joins with it. 
3. Another tRNA joins next to the last, complimentary to the mRNA triplet codon there. 
4. By the means of an enzyme, and ATP, the two amino acids on the top of the tRNA's are joined by a peptide bond. 
5. The ribosome moves on to the next codon in the sequence of the mRNA - another tRNA joining to it, aligning the amino acids in order for these to also be joined via a peptide bond. 
6. This process continues until a stop codon is reached. At this point, there will be a full polypeptide chain formed - the ribosome, mRNA, and final tRNA all detatch. 

Unit 1 Recap: 

Secondary stucture - the polypeptide is coiled or folded 

Tertiary structure - secondary structure is folded 

Quaternary structure - different polypeptide chains linking. 

In Translation, mRNA's function is to act as a template on which the polypeptide is formed.

tRNA acts as a carrier for the amino acid. Without tRNA to carry the amino acid AND attach to the mRNA on opposite sides, the amino acids could not line up.