PCB 3063 Exam 4 Review

Vocabulary flashcards covering E. coli operon control, DNA repair systems, gene regulation, and mutation types based on Exam 4 material.

CAP (E. coli lac operon)

A form of positive inducible control.

RITS

A complex that consists of siRNAs and proteins.

Flanking direct repeats

Sequences associated with practically all studied transposable elements.

Base excision repair (nucleotide addition)

Process in which DNA polymerase is needed to add nucleotides to the exposed $3'-OH$ group.

Negative inducible control (repressor absence)

A condition where the structural gene would be constitutively expressed if a mutation eliminated the repressor protein.

Nonsense mutation

A mutation that changes an amino acid sequence to a shorter version, such as Met‐Ala‐Gln‐Arg‐Glu‐Leu becoming Met‐Ala, by introducing a premature stop codon.

Chromatin-remodeling complexes

Complexes that can reposition nucleosomes, cause conformational changes in DNA, and interact with transcription factors, but do not alter the chemical structure of histones.

Photoreactivation (E. coli)

A DNA repair system that does not involve the activity of a DNA polymerase.

DNA glycosylase

A protein that does not play a role in nucleotide-excision repair but is involved in base-excision repair.

Trp operon (tryptophan absence)

The state in which the regulator dissociates from the operator and structural genes get transcribed.

P bodies

Cellular structures where RNA degradation is known to occur.

Cystic fibrosis

An example of a genetic disorder in humans that results from a loss-of-function mutation.

cAMP (lac operon function)

Acivates an activator protein (CAP) to regulate the operon.

Dicer enzymes

Enzymes responsible for the cutting and processing of double-stranded RNA to produce siRNAs and miRNAs.

DNA-binding proteins

Proteins that bind dynamically to DNA, affect gene expression, and often use specific amino acids to form hydrogen bonds with DNA.

Regulatory genes

Genes that are generally constitutively transcribed.

Mediators

Protein complexes involved in regulating transcription rates in eukaryotic gene regulation.

FLD (Arabidopsis)

A deacetylase enzyme that stimulates flowering by deacetylating histones that bind to the FLC gene, causing repression of FLC transcription.

Pyrimidine dimers

The type of DNA lesion specifically caused by ultraviolet light.

RNA interference

A process also known as RNA silencing or posttranscriptional gene silencing.

Cis-acting promoter

A promoter that affects only genes that are located on the same piece of DNA.

Alternative splicing

A regulatory process important in the sexual development of Drosophila melanogaster.

Allolactose

The substance responsible for the induction of the lac operon.

Somatic mutation

A mutation that affects the individual animal in which it occurs but cannot be passed on to its offspring.

Negative transcriptional control

Transcriptional control that occurs when an active repressor protein binds to the operator.

Frameshift mutation

A mutation resulting from the insertion or removal of one or more nucleotide base pairs in DNA.

Silent mutation

A type of mutation that does not lead to a change in the amino acid sequence of the gene product.

Germ-line mutations

Mutations that occur in gametes and can be passed on to offspring, unlike somatic mutations.