#3: Protein Synthesis -Transcription

Question 1

Transcription

Answer 1

the process of producing a strand of mRNA from DNA

occurs in the nucleus of a cell

Question 2

Stage 1 – Initiation

Answer 2

RNA polymerase binds to the molecule of DNA and begins to unwind it

exposed DNA is now ready to be transcribed

RNA polymerase now adds complementary nucleotides

RNA binds to promoter (TATA box)

Question 3

Stage 2 – Elongation

Answer 3

a complementary strand of mRNA is produced from the DNA template

mRNA is produced in a 5’ to 3’ direction

Question 4

Stage 3 – Termination

Answer 4

RNA polymerase recognizes the terminator sequence at the end of the gene to be transcribed and the strand of mRNA is released

Question 5

mRNA Modified

Addition of 5’ cap

Answer 5

add 7 Gs on 5’ end

protects the strand of mRNA from being digested in the cytoplasm
plays an important role in the binding of the ribosome to the mRNA strand

Question 6

mRNA Modified

Addition of a poly-A tail

Answer 6

add multiple A’s on 3’ end

attaches to the 3’ end of the strand of mRNA
protects the strand of mRNA from being digested in the cytoplasm

Question 7

mRNA Modified

Removal of the introns

Answer 7

introns are nonsense coding (found in DNA and mRNA) that, if translated, would interfere with the functioning of THAT particular protein
the introns are removed from the strand of mRNA before it leaves the nucleus

Question 8

Wobble Hypothesis

Answer 8

More than 1 codon matches with an amino acid

The redundancy allows 3rd base in codon to change while allowing codon to code for same amino acid