Nucleic Acids and Transcription

Question 1

The Central Dogma

Answer 1

DNA (transcription) mRNA (translation) Protein

Question 2

Template Strand

Answer 2

Carries the gene of interest, can change depending on what the gene of interest is

Question 3

Nontemplate, or noncoding Strand

Answer 3

Opposite the Template Strand. Is noncoding for the gene of interest, but can change depending on what the gene of interest is

Question 4

Template strand is read from

Answer 4

3’-5’

Question 5

mRNA is transcribed from

Answer 5

5’-3’

Question 6

Promoters in Eukaryotes

Answer 6

Transcription initiated at promoter sequence. TATA box is promoter

Question 7

Terminator Sequence

Answer 7

Transcription ends at this sequence

Question 8

Initiation in Prokaryotes

Answer 8

Sigma protein will bind to RNA polymerase and determine where the promoter is

Question 9

Promoters in Prokaryotes

Answer 9

40-50 base pairs. TATAAT box upstream ~10 bases (Pribnow box), and another 6 base sequence ~35 bases.

Question 10

Transcription Process in Eukaryotes

Answer 10

General transcription factors bind to the promoter and transcriptional activator proteins bind to enhancers. Requires basal transcription factors to work. Through looping of DNA, transcriptional activator proteins, mediator complex, RNA Pol II, and general transcription factors are brought into close proximity, allowing transcription to proceed. Transcription takes place inside the RNA-DNA duplex bubble.

Question 11

Transcription/Translation in Prokaryotes

Answer 11

mRNA is the primary transcript, the final message. Transcription and translation are coupled. Translation can begin before transcription has finished.

Question 12

Post-Transcriptional Modifications

Answer 12

Nucleotide 5’ cap is added. Introns are excised and exons are spliced together. Addition of a Poly-A tail to the 3’ end. “Splicing”.

Question 13

Polyadenylation

Answer 13

Adds a poly A tail to the 3’ end

Question 14

5’ cap

Answer 14

Consists of a modified base linked by its 5’ carbon tot he 5’ end of the primary transcript by a bridge composed of three phosphates

Question 15

Poly A Tail

Answer 15

Helps move mRNA to where it needs to go, serves as a stabilizing force for RNA on 3’ end

Question 16

Spliceosome Components

Answer 16

Attack specific sequence to cut out introns, The spliceosome enables a reaction that cuts one end of the intron and connects it to a nucleotide near the other, forming a loop.

Question 17

Lariat

Answer 17

Loop formed by the spliceosome, which quickly breaks down into nucleotides after cutting both parts of the intron. Exons are then joined together.

Question 18

Alternative Splicing

Answer 18

The idea that the same mRNA, primary transcript can have many different final mRNA’s which make different proteins.

Question 19

DNA has an OH on the

Answer 19

2’ Carbon

Question 20

Polycistronic

Answer 20

One gene can translate many polypeptides, ex prokaryotes