Genes and Alleles Flashcards
Gene
DNA region responsible for the production of an RNA molecule
Promoter
The place where RNA polymerase attaches
Regulatory Regions
Places where transcription factor proteins attach
Positive Transcription Factors
Recruit RNA Polymerase
Increased RNA production
Negative Transcription Factors
Blocks the promoter
Decreased RNA production
How do TFs Bind?
OH bonds
Form spontaneously but are temporary
Why do TF bind to dsDNA?
Opening the DNA takes too much time and energy
Why do TF bind to several adjacent bp?
To increase specificity and strength
Environmental Gene Regulation
When a gene is on only in certain circumstances
Lac Repressor Gene
Negative TF
Homotetramer
Binds to DNA at regulatory sites and bends the DNA into a loop
Dependent on lactose concentration
Alleles
Different forms of a gene
Spatial Gene Expression
When a gene is on in only some cells
Temporal Gene Expression
When a gene is on in only some developmental stages
Genotype
All genes and alleles present in a cell or organism
Homozygote
Identical alleles of interest
