Unit 1.3

Question 1

mRNA

Answer 1

Carries complementary copy of DNA code from the nucleus to the ribosome
Each base of triplet is known as a codon

Question 2

tRNA

Answer 2

triplet of bases is known as an anticodon
Specific amino acid attachment site at the top
And carries specific amino acid to the ribosome Each base

Question 3

rRNA

Answer 3

Composed of ribosomes and proteins

Question 4

Transcription

Answer 4

•RNA polymerase moves along DNA unwinding the double helix and breaking the hydrogen bonds between bases. RNA polymerase synthesis a primary transcript of mRNA from RNA nucleotides by complementary base pairing
• RNA molecules can only add nucleotides onto the 3’end
•The mRNA produced from is known as the primary transcript

Question 5

Translation

Answer 5

The mRNA mature transcript leaves the nucleus to the ribosomes for the process of translation into a polypeptide

Translation starts at the START corn and ends at a STOP codon. This is very important to ensure the entire polypeptide chain is produced whiteout any amino acids missing

The ribosome exposes one codon on the mRNA allowing tRNA to bring a specific amino acid to the ribosome. The correct anticodon on the tRNA will complementary base pair with the codon on the mRNA, bringing the correct specific amino acids with it. The ribosome exposes the next codon where another tRNA and its amino acids will complementary base pair with that codon.

Aligning amino acids are joined together by a peptide bond allowing the tRNA to leave the ribosome as the polypeptide is formed. This happens throughout the length of the mRNA until it reaches a STOP codon