Translation and transcription Flashcards
1
Q
What is transcription?
A
where one gene on the DNA is copied into mRNA
2
Q
What is the process of transcription?
A
- the DNA helix unwinds to expose the basis to act as a template
- only one chain of DNA acts as a template
- like DNA replication, this unwinding and unzipping is catalysed by DNA helicase
- DNA helicase breaks the hydrogen bonds between bases
- free mRNA nucleotides in the nucleus align opposite exposed complementary DNA bases
- the enzyme RNA polymerase bonds together the RNA nucleotides to create a new RNA polymer chain, one entire gene is copied
3
Q
What is the anticodon complimentary to in translation?
A
the anticodon in tRNA is complimentary to the codon on the mRNA
4
Q
What is the process of translation?
A
- when the mRNA has left the nucleus, it attaches to the ribosome in the cytoplasm
- the ribosome attaches at the start codon
- the tRNA molecule with the complementary anticodon aligns opposite the mRNA, held in place by the ribosome
- the ribosome will move along the mRNA molecule to enable another complementary tRNA to attach to the next codon on mRNA
- the two amino acids that have been delivered by the tRNA molecule are joined by a peptide bond, this is catalysed by an enzyme and requires ATP
- this continues until the ribosome reaches the stop codon at the end of the mRNA molecule, the amino acid chain (primary structure) then detaches and changes its structure