gene expression - transcription (lecture 11)

Question 1

explain the process of DNA to RNA

Answer 1

this process if transcription
- DNA dependant RNA synthesis

Question 2

what is a gene?

Answer 2

vary difficult to describe in one way, therefore theres a large variation in answers, but one is:

a defined region (sequence) of DNA that produces a type of RNA molecule that has some function

Question 3

describe gene expression

Answer 3

the process by which info from a gene is used in the synthesis of a functional gene product: protein or noncoding RNA

Question 4

outline the three steps of DNA to RNA transcription

Answer 4

1 initiation
2 elongation
3 termination

Question 5

outline the process of initiation during DNA transcription

Answer 5

• transcription factors bind to the TATA box region of the promoter on the coding strand
• RNA polymerase II binds forming a transcriptional initiation complex with tf^
• separating the two DNA strand and beginning mRNA synthesis
• helicase enzyme then arrives to continue the separation of the DNA strands by breaking hydrogen bonds
• RNA polymerase II begins mRNA synthesis

Question 6

outline the process of elongation during DNA transcription

Answer 6

• producing RNA
• RNA polymerase II allows for the placement of RNA nucleotides pairing with the DNA template strand
• the template strand copied runs 3’-5’ to ensure RNA will read correctly 5’-3’
• as the RNA pol II moves along the DNA winding up the end of the dsDNA therefore topoisomerase II is recruited to release the tension