7.3 Translation

Question 1

How does tRNA activiation work?

Answer 1

A tRNA activating enzyme binds to ATP and a specific amino acid, then the tRNA comes too and the ATP binds the amino acid to the tRNA, making a high-energy bond. The finished tRNA then leaves the enzyme.

Question 2

Outline the first step in translation.

Answer 2

1. A small ribosomal subunit binds to the start codon. The first tRNA binds and then the large ribosomal subunit binds too.

Question 3

How is the correct amino acid sequence ensured?

Answer 3

each tRNA has a specific anticodon, which corresponds to a specific amino acid and a specific codon on the mRNA

Question 4

What are the 3 regions of the translation complex?

Answer 4

E, P, A

Question 5

What happens during Elongation in translation?

Answer 5

The next tRNA binds to the A-site, and the amino acids form peptide bonds. Then the trnaslationcomplex moves one codon further, and the uncharged tRNA leaves via the E site. Etc etc etc

Question 6

What happens at the end of translation?

Answer 6

Once the translation complex reaches the stop codon, a release factor binds to the A site, and makes the tRNA let the polypeptide go.

Question 7

Where does translation occur? What is the difference of how fast translation can occur between eukaryotes and prokaryotes.

Answer 7

In ribosomes. In prokaryotes, translation can occur immedieately after transcription due to the lack of a restricting nucleus.

Question 8

What are polysomes? How can you identify them?

Answer 8

they are multiple ribosomes translating a mRNA at the same time, you can identify them as beads on a string

Question 9

What do the ribosomes in the rER do? What do free ribosomes do?

Answer 9

They make proteins either of secretion or for lysosomes. The free ribosomes make protein for the cell itself.