Gene Transcription and mRNA Processing

Question 1

Predict how mutations in different functional elements of a typical polypeptide-encoding gene might impact the function of that gene

Answer 1

mutations in:
promoter: inhibit transcription of gene
coding sequence: cause shift in reading fram

Question 2

Describe the three primary-post transcriptional modifications that occur when converting a pre-mRNA to a mRNA

Answer 2

Addition of the 5’ Cap - important for ribosome binding to mRNA + prevents degradation of 5’ end

Addition of poly-A tail - on 3’ end prevents degradation

Intro Removal - by spliceosome (alternate splicing)

Question 3

List the primary functions of different classes of RNA as the occur in healthy human cells

Answer 3

mRNA - code for polypeptides
tRNA - associate a 3 nucleotide sequence with an amino acid
rRNA - make up components of ribosome

Question 4

Explain how different RNA polymerases work to carry out synthesis of different classes of RNA

Answer 4

RNA Pol I - make rRNA
RNA Pol II - make mRNA, snRNA, miRNA
RNA Pol III - make tRNA