ch. 16 Flashcards
what is a 3’UTR?
3’ untranslated region; region just downstream of the protein-coding region in an RNA molecule that is not translated
what is a 5’ cap?
a methylated guanosine triphosphate (GTP) molecule that is attached to the 5’ end of a mRNA to protect the end from degradation
what is a 5’ UTR?
5’ untranslated region; region just upstream of the protein-coding region in an RNA molecule that is not translated
what is an activator protein?
a protein that binds to prokaryotic operators to increase transcription
what is a catabolite activator protein?
a protein that complexes with cAMP to bind to the promoter sequences of operons which control sugar processing when glucose is not available
what is are cis-acting elements?
transcription factor binding sites within the promoter that regulate the transcription of a gene adjacent to it
what is a diner enzyme?
enzyme that chops the pre-miRNA into the mature form of the miRNA
what is DNA methylation?
epigenetic modification that leads to gene slicing; a process involving adding a methyl group to the DNA molecule
what is an enhancer?
a segment of DNA (that is upstream, downstream, perhaps thousands of nucleotides away, or on another chromosome) that influence the transcription of a specific gene
what does it mean if traits are epigenetic?
they are heritable changes that do not involve changes in the DNA sequence
what is a eukaryotic initiation factor-2?
(elF-2) a protein that binds first to an mRNA to initiate translation
what is gene expression?
the processed that control the turning on or off of a gene
what is GDP?
a molecule that is left after the energy is used to start translation
what is GTP?
an energy-providing molecule that binds to eIF-2 and is needed for translation
what is histone acetylation?
the epigenetic modification that leads to gene silencing
what is gene silencing?
a process involving adding or removing an acetyl functional group
what is an inducible operon?
an operon that can be activated or repressed depending on cellular needs and the surrounding environment
what is an initiation complex?
a protein complex containing eIf-2 that starts translation
what is a lac operon?
an operon in prokaryotic cells that encodes genes required for processing and intake of lactose
what is a large 60S ribosomal subunit?
the second, larger ribosomal subunit that binds to the RNA to translate it into protein
what is miRNA?
small RNA molecules (approx. 21 nucleotides) that bind to RNA molecules to degrade them
what is myc?
an oncogene that causes cancer in many cancer cells
what is a negative regulator?
a protein that prevents transcription
what is the operator region of DNA?
region outside the promoter region that binds activators or repressors that control gene expression in prokaryotic cells
what is an operon?
a collection of genes involved in a pathway that are transcribed together as a single mRNA in prokaryotic cells
what is a poly-A tail?
a series of adenine nucleotides that are attached to he 3’ end of an mRNA to protect it form degradation
what is a positive regulator?
a protein that increases transcription
what does post-transcriptional mean?
control of a gene expression after the RNA molecule has been created but before it is translated into protein
what does post-translational mean?
control of gene expression after a protein has been created
what is a proteasome?
an organelle that degrades proteins
what is a repressor protein?
a protein that binds to the operator of prokaryotic genes to prevent transcription
what is a RISC?
a protein complex that binds along with the miRNA to the RNA to degrade it
what is RNA stability?
how long an RNA molecule will remain intact in the cytoplasm
what is RBP (RNA-binding protein)?
a protein that binds to the 3’ or 5’ UTR to increase or decrease the RNA stability
what is a small 40S ribosomal subunit?
a ribosomal subunit that binds to the RNA to translate it into protein
what is a trans-acting element?
a transcription factor binding site found outside the promoter or on another chromosome that influences the transcription of a particular gene
what is a transcription factor?
a protein that binds to the DNA at the promoter or enhancer region and that influences transcription of a gene
what is a transcription factor binding site?
a sequence of DNA to which a transcription factor binds
what is a trp operon?
a series of genes necessary to synthesize tryptophan in prokaryotic cells
what is tryptophan?
an amino acid that can be synthesized by prokaryotic cells when necessary
what is an untranslated region?
a segment of the RNA molecule that is not translated into protein; these regions lie before and after the protein-coding region
