Chapter 4 Flashcards
Enhancer
a region of DNA that can increase the expression of a gene.
Exon
The region of a gene that directly codes for a protein.
Gel electrophoresis
Using electricity to separate molecules on a gel slab.
Transcription factors
Molecules that bind to regulatory regions to affect the expression of a gene.
Medium
Source of nutrients, in liquid or solid form, for growing cell cultures.
Operon
A region on prokaryotic DNA where one or more genes and their controlling elements are located.
Regulatory molecule
when it binds to an operator on an operon, gene expression is turned off.
Vector
A DNA molecule that is used as a vehicle to carry foreign pieces of DNA into a cell.
What is agarose for?
horizontal and separates larger molecules (DNA). If molecules are very large, decrease the % of agar.
What is polyacrylamide for?
vertical and separates smaller molecules (proteins and peptides)
Mutagenesis
inducing change at a particular locus on a DNA molecule (chemicals, radiation, viral infection). It can result in additions or deletions to DNA, improved protein function, or cell death.
E. coli
bacteria that has about 2000 genes and divides every 20 minutes under ideal conditions.
3 types of Eukaryotic gene expression regulators
enhancers, transcription factors, histone-DNA complexes.
Enhancers
DNA sequences that regulate gene expression by increasing the likelihood that a gene will be transcribed
transcription factors
proteins that control the rate at which DNA is transcribed into messenger RNA (mRNA)
histone-DNA complexes
controlling the accessibility of DNA to transcription factors through various modifications on histone proteins, essentially determining whether a gene is actively transcribed or silenced
Why recombinant protein therapies?
a body doesn’t synthesize enough of a certain protein, or doesn’t produce the protein at the right time, or it produces a defective protein.
Tris buffer
buffer used in gel electrophoresis to stabilize pH, conduct electricity, and maintain the shape of molecules
Ethidium bromide
stain that causes DNA run on a gel to glow orange when exposed to UV light.
Four similarities in DNA from one organism to another
- Same bases (A,T,C,G)
- Double helix structure held together by H bonds
- Strands are antiparallel
- Replicate in semi-conservative fashion
Mechanism of an operon
Unit compose of a promoter, one or more structural genes, and a terminator.
RNA polymerase binds to the promoter site to activate gene, works its way down to the structural gene, and then synthesizes the mRNA that will get translated into a peptide chain. Transcription can be halted if a regulatory molecule binds to the operator region, blocking RNA polymerase.
How gene therapy is used for patients with cystic fibrosis
A functional cystic fibrosis transmembrane conductance regulator (CFTR) gene was inserted into a modified adenovirus and delivered to the cells that line the nose.
