Lesson 4B: Protein Synthesis: Translation

Question 1

Translation

Answer 1

The process of assembling a protein from the genetic information on an mRNA molecule
requires tRNA and Ribosome to work together

Question 2

tRNA

Answer 2

the molecule that carries amino acids to the ribosomes, every tRNA molecule contains an anti-codon that complements a codon found on the mRNA strand

Requires tRNA and ribosomes to be working together

Question 3

Ribosomes pt 1

Answer 3

A specialized structure that “reads” the mRNA and co-coordinates the actions of the tRNA and the assembly of protein
Has two subunits:
Small subunit - reads mRNA
Large subunit- handles tRNA

Question 4

Ribosomes pt 2 binding sites for large subunit

Answer 4

1. A Site
2. B Site
3. E Site

Question 5

Translation step 1: initiation

Answer 5

Translation starts when an mRNA molecule binds to the active ribosome which reads the mRNA in the 5’-3’ direction. The ribosome reads the initiator codon (AUG) and the tRNA that contains the anti-condon base pairs at the A site bringing the amino acid, methionine

Question 6

Translation step 2: Elongation

Answer 6

the tRNA bound to the A-sit of the ribosome slides into the P-site as the ribosome moves along the mRNA.

A new tRNA carrying a new aa corresponding to the condon exposed in the A-site binds to the ribosome.

A peptide bond forms between the new amino acid and the aa attached to the tRNA in the P-Site forming a polypeptide chain on the A-Site.

the tRNA in the P-site slides into the E-site where it’s ejected and the process repeats

Question 7

Translation step 3: termination

Answer 7

Elongation continues until the ribosome reads a “stop” condon on the mRNA (UAA/UAG/UGA) when a stop condon is encountered a “release” factor binds to the termination codon and the complete polypeptide chain is released.
—The chain is then “processed” into a functional protein