Genetic Analysis 1 Midterm 3 Terms

Promoters

DNA sequences near beginning of genes that signal RNA polymerases to begin transcription

Terminators

Sequences in RNA products that tell RNA polymerase where to stop transcription

RNA Polymerase II

Transcribes genes that encodes proteins

Primary transcript

Result of transcription

Ribonuclease

Cleaves primary transcript to form new 3’ end

Poly-A Polymerase

Enzyme that adds As onto 3’ end exposed by ribonuclease cleavage

Introns

Sequences found in DNA of gene but not mature RNA

Exons

Sequences found in both gene’s DNA and mRNA

5’ and 3’ Untranslated Regions

Regions not translated, located right after methylated cap and just before poly-A tail

The three types of short sequences within primary transcripts that helo ensure splicing specifity

Splice donors, splice acceptors, branch sites

Lariat

When the new 5’ end of the intron attaches with a phosphodiester bond to an A at the branch site in the intron(first cut)

Spliceosome

Ensures that all splicing reactions take place in concert

Small Nuclear Ribonucleoproteins (snRNAs)

Five subunits that assemble anew on every primary transcipt to bring together two exons and catalyze intron removal

Ribozymes

RNA molecules that can act as enzymes and catalyze specific biochemical reactions

Splice Donor/Acceptor sites

5’ end (first cut and donor) and 3’ end (second cut and acceptor)

Alternative Splicing

Produces different mRNA molecules that may encode related proteins with different amino acid sequences and functions

Adenosine Deaminases Acting on RNA enzymes (RNA editing)

Changed adenosine nucleotides in primary transcripts to ionosine

Transformation

The ability of a substance to change the genetic characteristics of an organism