BIOCHEM FINAL -Protein synthesis / tRNA synthetase

tRNA activation (charging), initiation, elongation, termination

What are the 4 stages of translation

Attaching (charging) amino acids to the correct tRNA

What is the first step in converting mRNA into a protein?

Four arms

D arm, TψC arm, anticodon arm, and amino acid arm

What important structures do tRNAs have that help the cell recognize them?

Link the mRNA codon to the amino acid added to the protein

What does the folded shape of tRNA allow it to do?

The amino acid attached determines what will be added when its codon appears

Why is charging tRNA sometimes called the “second genetic code”?

Each recognizes one amino acid and all the tRNAs for that amino acid

How specific is each tRNA synthase?

ATP

What energy source do tRNA synthetases use to attach amino acids to tRNA?

The amino acid is linked to the 3’-OH of the terminal adenosine?

What is the final attachment point of the amino acid on the tRNA?

They proofread and remove incorrectly activated amino acids

How do tRNA synthetases prevent mistakes?

About 1 mistake per 10,000 amino acids added

How accurate is tRNA synthetase proofreading?

Lab-added amino acids inserted into proteins using engineered tRNA and synthetase pairs

What are “unnatural acids”?

To give proteins new chemical properties and expand what cells can make

Why introduce unnatural amino acids?