mRNA Translation Notes

CCC and UAA

• CCC and UAA are mentioned in the context of mRNA.
• Mature mRNA is represented as CCC and UAA.

Translation at the Ribosome

• Analogy: Translating "Hello. How are you?" without spaces into a language (like French) with fewer words.
• The ribosome reads the mRNA sequence.
• It identifies the start of a 'sentence' based on punctuation and capitalization.

Codons and Amino Acids

• There are 64 codons.
• One of these codons codes for methionine (MET) or start.
• There are 20 total amino acids.

Redundancy

• Analogy: More words in English to translate to fewer words in French.
• Redundancy means having more than one codon specify the same amino acid.
• Importance: Redundancy is important in the context of mutations.
• It can offer a 'backup' if a mutation occurs.

Mutations

• Mutations originate in the DNA and carry forward into the RNA.
• If a mutation does not affect the amino acid, it often involves the third letter of the codon.

Using the Codon Table

• Look up the three letters of the codon in the table.
• Example: The amino acid for the start codon is methionine (MET).
• Methionine is the first amino acid in the polypeptide chain.
• The ribosome reads the codons three letters at a time to determine the corresponding amino acids.
• Example: After the start codon, the ribosome shifts over to find the second codon (e.g., UUU) and determines the corresponding amino acid.

Process Overview

• The process of reading codons and identifying amino acids will be briefly reviewed.