Translation

Question 1

Simply, what is translation?

Answer 1

The second stage of protein synthesis

Question 2

What are ribosomes made up of?

Answer 2

• One small and one large subunit
• Proteins and rRNA

Question 3

Where does mRNA attach to the ribosome?

Answer 3

Along the middle

Question 4

In mRNA, there are codons, what are codons?

Answer 4

A sequence of 3 bases that code for 1 amino acid

Question 5

Genetic codes are degenerate, what does this mean?

Answer 5

• There can be different codons that code for the same amino acid
• For example, ACA/ACT/ACC all code for threonine

Question 6

What is tRNA made up of?

Answer 6

• RNA nucleotides
• 3 bases attached (anticodons) which are complementary to the mRNA codons

Question 7

What happens in the first stage of translation?

Answer 7

tRNA binds to the start codon of mRNA
- Start codon is always ATG which codes for methionine

Question 8

In the second stage, tRNA binds to another mRNA codon, carrying a different amino acid. What happens between these and how?

Answer 8

• The first amino acid (methionine) is transferred to the next amino acid by forming a peptide bond
• This is catalysed by the enzyme peptidyl transferase

Question 9

In the third stage, the second stage repeats with a third tRNA and amino acid, what happens to the first tRNA?

Answer 9

It is released to attach to its specific amino acid

Question 10

What happens as this process repeats?

Answer 10

• Amino acid chain is built and extends and leaves the ribosome
• Chain is twisted into secondary and tertiary structures