Discuss how the expression of a protein can be regulated post transcription in eukaryotic cells through, using the following key terms: Degradation of mRNA (two ways) Blocking translation Degradation of the protein

List two different ways in which trans-acting small RNAs(sRNAs) regulate the expression of target genes.

State whether each of the following would be likely to (generally) increase or decrease the transcription of a nearby gene and why. HMT activity Inhibition of DMT activity HAT activity  Inhibition of HDAC activity

Global regulation often occurs when cells are under stress and translation would waste energy or be harmful. A protein kinase called mTor is the major player in this method.  As a kinase it adds and removes phosphates from other molecules.  When the cell/organims is stressed, the mTor is inactivated.  It therefore doesn’t add phosphates to translation initiation factors and so they are inactive and translation stops.What happens when the cell/organims is NOT stressed?

Choose all that apply regarding gene transcription in eukaryotes: Multiple transcription factors are necessary to form the pre-initiation complex (PIC) of RNA Pol II. The 5' cap of mRNA requires the free triphosphate on the nucleotide at the 5' end. Introns must be removed from the initial RNA transcipt. Histone acetylation is a method controlling gene expression. Acetylation creates more positive charges on histones, leading to tighter binding of the proteins to DNA. Exons are removed from mRNA by the spliceosome. RNA polymerase II must completely finish an mRNA transcript before processing can begin. RNA polymerase I catalyzes the synthesis of the majority of ribosomal RNA. The hormone 173-estradiol binds to a G-protein coupled receptor to control gene transcription.

Select all the examples of mutations that are likely to have a global effect on gene expression. Check All That Apply a mutation in a splice donor recognition sequence within an snRNA gene a mutation that reduces expression of an rRNA a hypomorphic mutation in the catalytic site of RNA polymerase a silent mutation in a gene encoding a protein in the small ribosomal subunit a nonsense mutation in a gene encoding an ion channel

Positive and negative regulator proteins that bind to enhancer regions of the DNA and stimulate or inhibit transcription in eukaryotes are known as: translation inhibitors. translation regulators. special transcription factors. basal transcription factors.

Determine whether the following will increase or decrease gene expression: mRNA degradation mRNA capping Binding of a transcriptional activator Ubiquitination of a protein and targeting to the proteasome

Describe three (3) ways in which the primary transcript is modified as it is converted to mRNA.

Compare and contrast the formation of mRNA in bacterial and eukaryotic cells. How do the differences affect the way in which each type of mRNA is translated? Does one system have any obvious advantage in terms of energy cost? Which system offers greater opportunities for control of gene expression?