Topic 6.3 - Transcription and RNA Processing

Question 1

how does genetic information flow?

Answer 1

from DNA -> RNA -> protein

Question 2

where is genetic information typically stored?

Answer 2

in DNA molecules

Question 3

what are RNA molecules used for?

Answer 3

to facilitate protein synthesis using DNA information

Question 4

what do ribosomes do?

Answer 4

contain RNA and assemble proteins

Question 5

transcription

Answer 5

the process in which an enzyme directs the formation of an mRNA molecule

Question 6

what happens during transcription

Answer 6

DNA molecules are separated

Question 7

what are the two strands being synthesized

Answer 7

the coding and non-coding strand

Question 8

where is the gene targeted for transcription located?

Answer 8

the coding strand

Question 9

how does RNA polymerase synthesize mRNA?

Answer 9

synthesizes mRNA in the 5’-3’ direction by reading the template in the 3’-5’ direction

Question 10

what is mRNA

Answer 10

the transcribed copy of a particular gene

Question 11

what are the types of RNA molecules (3)

Answer 11

> mRNA
tRNA
rRNA

Question 12

what is the purpose mRNA

Answer 12

carries genetic information from DNA -> ribosomes. this information is used to direct protein synthesis at the ribosomal site

Question 13

codon

Answer 13

a 3-base sequence found on mRNA

Question 14

what is the purpose of tRNA?

Answer 14

recruited to the ribosomes to help create a specific polypeptide sequence as directed by mRNA

Question 15

what do tRNA molecules carry?

Answer 15

a specific amino acid

Question 16

anti-codon

Answer 16

a 3-base sequence on tRNA

Question 17

what will the correct base pairing of anti-codons and codons result in?

Answer 17

the release and addition of an amino acid to a growing polypeptide

Question 18

what is rRNA?

Answer 18

functional units of ribosomes responsible for protein assembly

Question 19

what is the purpose of rRNA?

Answer 19

> base pairing of codons and anti-codons occurs in the ribosome
creates primary polypeptides as tRNA releases amino acids

Question 20

where do enzyme-regulated modifications occur?

Answer 20

in the mRNA transcript (in eukaryotes)

Question 21

what is the purpose of the addition of a poly-A tail

Answer 21

increases stability and helps with exporting from nucleus (100-200 A nucleotides)

Question 22

where is the poly-A tail added?

Answer 22

3’ end

Question 23

what is the purpose of the GTP cap?

Answer 23

protects transcript and helps ribosome attach to mRNA

Question 24

introns

Answer 24

sequences of an mRNA transcript that do NOT code for amino acids. they are easily excised during RNA processing

Question 25

what is not included in the mature mRNA transcript?

Answer 25

introns

Question 26

exons

Answer 26

sequences of an mRNA transcript that DO code for amino acids. these sequences are retained during RNA processing

Question 27

are different exons connected in the mature mRNA transcript?

Answer 27

yes

Question 28

alternative splicing

Answer 28

the process of splicing introns and connected retained exons in the mature mRNA transcript

Question 29

how can different mRNA transcripts be produced?

Answer 29

different mRNA transcripts can be produced from one primary transcript and exons can be retained in different variations

Question 30

can different mRNA transcripts lead to different proteins?

Answer 30

yes

Question 31

promoter

Answer 31

the nucleotide sequence that lies just before the gene and allows for the binding of RNA polymerase