DB Lecture 21: Overview of Gene Expression

Question 1

What is the flow of genetic information?

Answer 1

protein coding gene is transcribed by RNA polymerase into pre-messenger (pre-mRNA) –> the pre-mRNA is processed into mRNA –> the mRNA is translated by ribosomes into protein

Question 2

What kinds of RNAs encoded by the genome are not mRNAs?

Answer 2

transfer (tRNA)
ribosomal (rRNA)
micro (miRNA)
long non-coding (lncrRNA)

Question 3

List the levels at which the path from DNA to active/inactive protein is regulated.

Answer 3

1- transcriptional control
2- RNA processing
3- RNA transport and localization control
4a- mRNA degradation control
4b- translation control
5b- protein activity control

Question 4

What are the names of the nucleotide bases?

Answer 4

adenine
guanine
cytosine
thymine
uracil

Question 5

What are the names of the nucleosides?

Answer 5

adenosine
guanosine
cytidine
thymidine
uridine

Question 6

What is the difference between a nucleotide and a nucleoside?

Answer 6

nucleoside refers to a base + ribose

nucleotide refers to the base + ribose + phosphate

Question 7

What is linked at each ribose carbon in a nucleotide?

Answer 7

1’ - pyrimidine or purine base
3’ - hydroxyl group
2’ (in ribonucleotides) - hydroxyl group
5’ - phosphate

Question 8

What direction are nucleotide sequences read in?

Answer 8

5’ to 3’

Question 9

What direction are natural chains of nucleotides synthesized in?

Answer 9

5’ to 3’