The document discusses the concepts of codons, the genetic code, redundancy, and reading frames, emphasizing the relationship between codons, amino acids, and tRNAs. It explains tRNA charging and the functions of ribosomal elements, the steps in translation, and the involvement of various factors and sites during protein synthesis. Additionally, it highlights the process of protein degradation involving proteasomes, ubiquitin, and proteases.

1. What are codons, the genetic code, redundancy, and reading frames?
What are the important structural features of a tRNA?
What is the relationship between the number of possible codons, amino acids, and tRNAs?
What is tRNA charging? What is the enzyme responsible for tRNA charging?
What are ribosomes made of? What are the roles of the large and small subunit? What are the E,
P, and A sites? What is the function of the rRNAs?
What are the steps in translation including initiation, elongation, and termination? What are the
roles of the initiator tRNA, translation initiation factors, EF-Tu/EF1, EF-G/EF2, and release
factors?
What is the match between a codon and tRNA proofread?
What is a polysome?
What do proteasomes, ubiquitin, and proteases have to do with protein degradation (proteolysis)?
Solution
Codons: These are three letter codes, each letter coding for one of the four nitrogenous bases.
These codons make up the genetic code. Each codon identifies one amino acid.
Genetic code: The genetic code is made up of 64 different combination of codons which codes
for 20 different amino acids.
Redundancy: Although genetic code is made up of 64 codons, however there are only 20 amino
acids. This is because more than one codons can code for single amino acids. This is why genetic
code is redundant.
Reading frame: Reading frame is a way of dividing the genetic code into triplet codons that ends
in a stop codon such that it can be finally translated into functional proteins.