chapter 9 objectives Flashcards
operon and 1 advantage it provides
it is a cluster of genes that are transcribed together to a mRNA molecule that encodes for multiple proteins
one advatage: allows for simultaneous processes
parts of lac operon operation
regulator: codes for proteins capable of repressing operon
control locus: recognized by rna polymerase/ operator or on/off switch
structural locus: three genes coding for different enzymes needed to catabolize lactoes
conditions when the lac operon is functioning in the cell
low glucose levels and high lactose levels
recombination
bacteria donates DNA to another
recombinant
organism contains genes from another organism
conjugation
exchange of genes, donor retains copy of what is transferred
transfection
forced introduction of small molecules such as DNA RNA or anitbodies into eukaryotic cells
competent cell
can accept genetic material
role of plasmid
they are chromosome pieces that code for resistance factors
3 forms of horizontal gene transfer used in bacteria
conjugation: donor of bacteria retains a copy of genetic material that is being transferred cell-cell
transformation: acceptance by bacterial cell of small fragments of DNA from enviornment
transduction: transfer of genetic material by a bacteriophage
transposon
transposable elements capable of shifting from one part of the genome to another (chromosome to plasmid or cell to cell)
mutation (1 positive and 1 negative)
any change to nucleotide sequence in genome
positive: can lead to adaptations of organisms
negative: can be cancerous
wild type
a microorganism that exhibits a natural, nonmutated characteristics
mutant strain
a microorganism that shows variance in morphology, genetic control mechanisms, resistance to chemicals etc.
spontaneous mutation
a random change in the DNA arising from errors in replication
induced mutation
results from exposure to known mutagens, physical, or chemical agents that disrupt DNA (radiation or chemicals)
frameshift mutation
changes reading frame of mRNA because one or more bases are inserted or deleted
point mutation
addition, deletion, or substitution of single bases
nonsense mutation
creates a stop codon
silent mutation
alters base, but doesnt not change amino acid
missense mutation
creates a different amino acid
uv damage repair and excision
repairs mistakes in replication
use of restriction endonucleases
recognize foreign DNA and break bonds between nucleotides on both of the strands of DNA; this protects bacteria from DNA
use of PCR
used to replicate target DNA with a few copies to billions of copies within hours; diagnoses infections/diseases caused by single gene copy
use of dna sequencing
research to understand genetics/evolution
use recombinant dna
cloning genes for research/genetic engineering
use of gene therapy
treating genertic disorders by replacing/correcting defective genes
