RNA: Another level of gene control in prokaryotes

Question 1

RNA is….

Answer 1

Another level of gene control in prokaryotes

Question 2

Gene regulation using RNA molecules in prokaryotes:

Answer 2

Antisense RNA control

Riboswitches

Riboswitches that can act as Ribozymes

Question 3

antisense RNA

Answer 3

An RNA molecule (synthesized in vivo or in vitro) with a ribonucleotide sequence that is complementary to part of an mRNA molecule.

Question 4

Osmolarity

Answer 4

Osmolarity conditions affects movement of water across a membrane due to differences in ion concentrations on inside and outside of membrane

Question 5

____ proteins function as diffusion pores on ____ membrane

Answer 5

OmpF proteins function as diffusion pores on bacterial membrane

Question 6

Lower OmpF protein….

Answer 6

less diffusion across membrane

Question 7

Antisense RNA control under high osmolarity:

Answer 7

Lower OmpF protein; less diffusion across membrane

Question 8

Riboswitch control of translation

Answer 8

A Regulatory Protein binds to the Riboswitch and Stabilizes a Secondary Structure that masks a Ribosome-Binding site.
—–> No translation takes place.

Without the regulatory protein, the riboswitch assumes an alternative secondary structure that makes the ribosome-binding site available
—->Translation takes place.

Question 9

Riboswitch

Answer 9

Can be repressive (like the vitamin B12 example)

OR

the presence of the regulatory protein can cause a secondary structure that permits translation (inductive)

Question 10

Riboswitches that act as Ribozymes

Answer 10

GlcN6P gene: catalyzes reaction to produce a sugar, glucosamine-6-phosphate from a precursor

However, if there is plenty of GlcN6P around, it binds to the ribozyme region, altering its structure, leading to the active form of the ribozyme, which degrades the mRNA (doesn’t make more enzyme when its not needed!)