Chapter 3 - protein synthesis

Question 1

what is transcription?
(step 1)

Answer 1

1) DNA helicase unzips the section of DNA containing the gene - hydrogen bonds break
-sense strand=contains code for protein
-antisense strand=template strand for transcription
2) free nucleotides pair with complementary bases in antisense strand
3) RNA polymerase caused phosphodiester bonds to form between the nucleotides to from mRNA
4) mRNA detaches from antisense strand and leaves nucleus through nuclear pore
5) DNA double helix reforms
6) mRNA molecule travels to ribosomes in cell cytoplasm

Question 2

what is translation?
(step 2)

Answer 2

1) mRNA binds to specific site on ribosome where its held in place to be decoded or translated into amino acid sequence
2) tRNA anticodons bind to complementary codons along mRNA - amino acids brought together in correct sequence - form primary structure of protein coded by mRNA
3) amino acids added one at a time - polypeptide chain grows - ribosomes=binding site for mRNA and tRNA=catalyses assembly of protein