Transcription in Eukaryotic cells

Question 1

Transcription

Answer 1

first step in gene expression, involving copying a gene’s DNA sequence to make an RNA molecule.

Question 2

RNA polymerases

Answer 2

Enzymes which link nucleotides to form an RNA strand

Question 3

RNA polymerase II

Answer 3

Uses strand of DNA as a template to make a complementary strand of RNA - the mRNA transcript

Question 4

Three stages of transcription

Answer 4

Initiation, elongation, and termination

Question 5

Two stages of mRNA transcript process

Answer 5

Protection and splicing

Question 6

Protection

Answer 6

In this phase nucleotide sequences are added to each end of the mRNA transcript to protect it from degration that can occur outtside the nucleus

Question 6

5’ cap

Answer 6

single G nucleotide is attached to the 5’ end of the transcrip

Question 7

poly A tail

Answer 7

long sequence of A nucleotides at the 3’ end of the transcript

Question 8

Initiation

Answer 8

RNA binds to sequence of DNA called the promoter
Once bound the RNA polymerase separates the DNA strands, providing the single-stranded template needed for transcription

Question 9

Elongation

Answer 9

One strand of DNA called the template strands acts as a template for RNA polymerase.

Reads the base one at a time, the polymerase builds an RNA molecule out of complementary nucleotides, making a chain that grows from 5’-3’

Question 10

Termination

Answer 10

Sequences called terminators signal that the RNA transcript is complete

Once they are transcribed they cause the transcription be released from the RNA polymerase

Question 11

Splicing

Answer 11

Parts of the pre-mRNA (called introns) are chopped out, remaining pieces (called exons) are stuck back together.

Question 12

Polyadenylation signal

Answer 12

Signal that shows up during protection phase of transcription that signals an enzyme to chop the RNA in two at that molecule.

Question 13

Splicesome

Answer 13

RNA complex that removes introns