Elizabeth Duncan - Chapter 5: Bacterial Transformation and Polymerase Chain Reaction

What is the clinical significance of bacterial transformation in biotechnology?

explains antibiotic resistance spread, enables genetic engineering for insulin production, and underlies gene therapy vectors

When did Griffith discover transformation?

1928

How did the mouse die in station 1?

pneumonia from the encapsulated bacteria

What did the S-Strain contain?

polysaccharide capsule

How was the R-strain different from the s-strain?

lacked capsule

What happened in station-3 of griffith’s experiment?

heat killed s-strain was injected into the mouse

What happened in station 4?

mouse died from pneumonia from live s-strain

How did the bacteria demonstrate genetic variation?

bacteria acquires traits from other dead bacteria

What happens during DNA release and uptake in the transformation process?

s chromosome released from heat-killed bacteria contained capsuled synthesis gene and recipient bacteria incorporates dna through cell membrane

What happens during DNA integration?

nucleuses degrade one DNA strand while complementary strand integrates via homologous recombination

What happens during bacterial division in the transformation process?

dividing bacteria replicates hybrid chromosome containing s strain capsule gene, daughter cells inherit transformed genotype with capsule capability

What is the clinical significance of bacterial conjugation?

explains horizontal gene transfer mechanisms responsible for rapid antibiotic resistance dissemination.

What are the different bacterial mating types?

F+ bacteria and F- bacteria

What is the fertility factor?

episomal DNA conferring donor ability

What is the conjugation bridge?

the pilus extending from f+ cell to establish physical contact

How are genes transferred during conjugation?

by the conjugation bridge through the pilus

What is high frequency recombination?

High frequency cell transfers chromosomal in addition to F factor sequence

What is bacterial transduction?

enables bacteriophages to transfer genetic material between bacteria

What happens during bacteriophage attachment?

bacteriophage recognizes receptor sites of bacterial surface

What happens during phage DNA replication?

DNA segment comprises fragmented bacterial chromosomal DNA, phage DNA directs synthesis of phage-encoded enzymes, replicating phage DNA uses bacterial machinery for viral Genome amplification

What are the steps of generalized transduction?

bacteriophage attachment, DNA injection and fragmentation, phage DNA replication, packaging error and phage release

What happens during prophase integration and excision?

donor bact harbors integrated prophage DNA within chromosome, donor DNA includes both phage and adjacent bacterial genes, temperate phage integrates at specific attachment sites in bacterial chromosome, aberrant excision removes phage DNA with flanking bacterial genes

What is hybrid DNA formation?

Hybrid DNA contains partial phage Genome fused with specific bacterial genes

How is DNA transferred to recipient?

recipient bacteria receives hybrid DNA through phage infection, rec. bact. undergoes homologous recombination with incoming DNA, hybrid DNA integrates via site-specific recombination, stable transductiants express donor genes after chromosomal integration

What is the pre-integration state?

What is the post-integration state?

What is the clinical significance of bacterial transduction?

How did genetic engineering revolutionize medicine?

What is the donor plasmid?

What are restriction enzymes?

What are DNA ligase?

Where do foreign DNA come from?

What is a chimera?

What does CaCl2 solution do to cells?

How does the host bacteria reproduce quickly?

How can recombinant proteins be used?

How did PCR revolutionize medicine?

What are primers?

What are dNTPs?

What is Taq DNA polymerase?

What are the three steps of PCR?

What temp does denaturation occur at?

What happens djuring the denaturation phase?

What temp does annealing happen?

What happens during annealing phase?

What temp does elongation happen at?

How does PCR multiply? (mathematical formula)

How many cycles of PCR are typical?