post translation and transcription

Regulatory segments of DNA that function to increase transcription levels in eukaryotes are called:

Enhancers

What is the primary difference between enhancers and proximal control elements?

Enhancers are located thousands of nucleotides away from the promoter; proximal control elements are close to the promoter

In what ways do Eukaryotes regulate gene expression at the post-transcriptional level :

• Alternative splicing

• RNA processing

• RNA interference

mRNA transcripts must be transported to :

The cytoplasm where they are translated by ribosomes

What does the 5’ cap & poly-A tail of mRNA molecules do:

Protects the mRNA from degradation by enzymes

When transporting out if Nucleus Unprotected mRNA gets:

Degraded and turns off the gene

When transported out of the nucleus protected mRNA gets :

Translated and turns on the gene

What best describes the function of RNAi?

Small RNA molecules interfere with translation by blocking a target mRNA’s ability to bind to a ribosome

What are 2 possible scenarios that turn gene expression off during RNA interference:

• mRNA is degraded

• Ribosome is blocked from binding

What are the 2 classes of RNAs involved in RNA interference :

• microRNAs

• Small interfering RNAs (siRNAs)

MicroRNAs have a ___________ precursor

Single-stranded

siRNAS have a ____________ precursor

Double-stranded

Protein activity can be controlled by post translational modifications or degradation by _____________

Proteases

Protease is an enzyme that :

Degrades proteins by breaking polypeptide bonds making single amino acids

Protein degradation is one strategy to control gene expression and is considered:

Post translational control

Post translational modifications of proteins can affect :

• Protein function

• Protein location within the cell

• Protein activation, or inactivation

• Protein degradation

Small peptide used by eukaryotic cells to mark proteins for degradation

ubiquitin

Cellular enzyme that adds the ubiquitin peptide to the target protein

Ubiquitin ligase

Ubiquitin ligase adds ubiquitin peptide to:

mis-folded or non functioning proteins