Transcription

Question 1

What direction does the DNA Pol move along the parental strand

Answer 1

DNA Poly moves in a 3’ to 5’ direction along the parental strand

Question 2

What are the regions in a gene?

Answer 2

The regulatory region and the transcribed region

Question 3

What is included in the regulatory region?

Answer 3

• 10 and 35 box that help bind RNA polymerase

- binds activators and repressors to vontrol gene expression

Question 4

What is included in the transcribed region?

Answer 4

Region is transcribed by an RNA Polymerase moving in the 3-5 direction on a template strand
RNA is the gene product of transcription

Question 5

What is the +1 site?

Answer 5

The Transcription start site (not to be confused with the start codon)

Question 6

What are the three RNAs?

Answer 6

tRNA: transfer RNA
mRNA: messenger RNA
rRNA: ribosomal RNA a structural component of the ribosome

Question 7

What are the three stages of transcription?

Answer 7

Initiation: Promoter is recognized by proteins and RNA poly. is recruited
Elongation: RNA pol adding new nucleotides
Termination: RNA Poly bumps into hairpin and falls of the DNA

Question 8

What streams do the regulatory and transcribed region follow

Answer 8

RR: upstream towards 5 end of the coding strand/non template strand
TR: downstream towards the 3’ carbon

Question 9

Summary of Initiation and Elongation

Answer 9

• DNA opens, RNA polymerase threads through the inner template strand
• RNA nucleotide triphosphates come and base pair with the template strand
• The energy increases as elongation continues and the RNA polymerase escapes from the sigma or transcription factors and continues

Question 10

DNA is read…

and new mRNA is synthesized…

Answer 10

3-5

5-3

Question 11

What are the ways to terminate transcription?

Answer 11

Hairpin loops

Proteins get involved to knock RNA pol off of DNA

Question 12

Describe mRNA processing in Eukaryotes

Answer 12

• the 5 cap (methylated guanine) is added to the mRNA so the ribosome recognize the MRNA and bind to it
• 3 Poly-A-tail added to the end of the mRNA transcript to protect against degradation
• Splicing: removes introns from pre-mRNA to allow for more than one protein to be made

Question 13

What does a mature mRNA consist of?

Answer 13

• 5 cap
• 3 poly-a- tail
• all introns removed

Question 14

Introns versus Exons

Answer 14

Introns are non-coding regions

Exons are protein coding regions