AP Bio: Unit 6

What is gene expression?

The process by which information from a gene is used to synthesize a functional gene product, typically a protein.

What is transcription?

The first step of gene expression where the DNA sequence of a gene is transcribed to produce mRNA.

What is translation?

The process of synthesizing a protein from the mRNA transcript.

What role do ribosomes play in translation?

Ribosomes facilitate the decoding of mRNA into a polypeptide chain (protein).

What is mRNA?

Messenger RNA; a type of RNA that conveys genetic information from DNA to the ribosome.

What is a promoter?

A DNA sequence that initiates transcription of a particular gene.

What is a transcription factor?

Proteins that help regulate gene expression by binding to specific DNA sequences.

What is an enhancer?

A regulatory DNA sequence that increases the likelihood of transcription.

What is a silencer?

A DNA sequence that can inhibit transcription when bound by repressor proteins.

What is an operator?

A segment of DNA that a repressor can bind to, blocking RNA polymerase from binding to the promoter.

What is alternative splicing?

The process by which different combinations of exons are joined to produce multiple mRNA variants from one gene.

What is post-transcriptional modification?

Chemical modifications of mRNA after transcription, including 5' capping, polyadenylation, and splicing.

What does 'lac operon' regulate?

The metabolism of lactose in E. coli.

What are oncogenes?

Genes that have the potential to cause cancer when mutated.

What are tumor suppressor genes?

Genes that help regulate cell division and prevent uncontrolled growth.

What is a histone?

Protein molecules around which DNA is wrapped to form nucleosomes.

What is chromatin remodeling?

The process through which the structure of chromatin is altered to allow access to DNA.

What is a genetic mutation?

A change in the DNA sequence that can affect gene function.

What is inducible expression?

Gene expression that is activated by the presence of a specific substance.

What is repressible expression?

Gene expression that is turned off in the presence of specific substances.

What is RNA interference (RNAi)?

A biological process in which RNA molecules inhibit gene expression by destroying specific mRNA molecules.

What is a knock-out mouse?

A genetically modified mouse in which a specific gene has been inactivated.

What are microRNAs (miRNAs)?

Small, non-coding RNA molecules that regulate gene expression by binding to complementary mRNA.

What is the role of the ribosomal RNA (rRNA)?

It forms the core of the ribosome's structure and catalyzes protein synthesis.

What is a coding sequence?

The part of the gene that is translated into protein.

What is the central dogma of molecular biology?

The framework for understanding the transfer of sequence information from DNA to RNA to protein.

What is a transcription bubble?

A region where the DNA strands have separated to allow transcription to occur.

What do spliceosomes do?

Complexes that remove introns from pre-mRNA during the processing of RNA.

What is a cap structure on mRNA?

A modified guanine nucleotide added to the 5' end of mRNA to protect it from degradation.

What is polyadenylation?

The addition of a poly(A) tail to the 3' end of mRNA to enhance stability and facilitate export from the nucleus.

What is the function of a transcriptional coactivator?

A protein that increases gene transcription by binding to an activator or the transcription machinery.

What is transcriptional repression?

The process that inhibits gene transcription.

What is gene regulation?

The mechanisms that cells use to increase or decrease the production of specific gene products.

What does the 'five prime untranslated region' (5' UTR) do?

Regulates translation, participating in ribosome binding.

What is meant by 'gene expression profiling'?

A technique used to measure the activity of thousands of genes at once to create a global picture of cellular function.

What are transcriptional enhancers?

DNA sequences that can greatly increase the likelihood that transcription of a particular gene will occur.

What is feedback inhibition in gene regulation?

A regulatory mechanism whereby the product of a process inhibits its own production.

What is the significance of the TATA box?

A DNA sequence that indicates where a genetic sequence can be read and decoded; a common promoter element.

What is the role of DNA methylation in gene regulation?

The addition of methyl groups to DNA, which can suppress gene expression.