Cellular control Flashcards
Chromosome mutations
affect the whole chromosome or number of chromosomes in a cell.
chromosome mutation deletion
a section of chromosome breaks off and is lost in the cell.
chromosome mutation duplication
sections get duplicated on a chromosome
chromosome mutation translocation
a section of one chromosome that breaks off and joins to a non-homologous chromosome (unlike chiasmata)
inversion
a section of the chromosome breaks off, gets inverted and rhen joins back onto the chromosome.
chromosome mutations can also…
affect the number of chromosomes. this is called aneuploidy
when chromosomes dont separate properly?
non- disjunction
operon
a group of genes under the control of the same operating system and expressed at the same time.
heterochromatim
tightly wound DNA, condensed chromosomes
euchromatin
DNA is loosely wound, here DNA transcription and DNA synthesis can take place.
Histone modification
adding acetyl or phosphate groups reduces positive charge of histones, negative DNA coils less tightly.
adding methyl group (methylation) increases positivity of histones so negative DNA winds more tightly.
lac z
beta galactosidase
lac y
lactose permease
lac a
transactylase
lac I
codes for repressor protein
binding site of RNA polymerase
Promotor
Transcription factors
protiens that control gene expression by stimulating or inhibiting the transcription of genes.
