BIOL 1000 Lecture 11: Lecture 11
2 Jul 2018
School
Department
Course
Professor
LECTURE 9 7/2/18
BIOL 1000-MOLECULAR BIOLOGY OF THE GENE
9.1: EXPERMENTS SHOWED THAT DNA IS THE GENTIC MATERIAL:
•Early in the 20th century, the molecular basis for the inheritance was a mystery.
•In 1928, Frederick Griffith was surprised to find that when he killed pathogenic bacteria, then
mixed the bacterial remains with living harmless bacteria.
I. Some living bacterial cells became pathogenic.
II. All of the descendants of the transformed bacteria inherited the newly acquired ability to
cause disease.
•By carefully choosing their model organism, Hershey and Chase were able to show that cer-
tain phages (bacterial viruses) reprogram host cells to produce more phages by injecting their
LECTURE 9 7/2/18
DNA.
9.2 VIRAL DNA MAY BECOME PART OF THE HOST CHROMOSOME:
•A virus is an infectious particle consisting of little more than “genes in a box”: a bit of nucleic
acid wrapped in a protein coat called a capsid and a membrane envelops.
LECTURE 9 7/2/18
•When phage DNA enters a lytic cycle inside a bacterium, it is replicated, transcribed and
translated.
Document Summary
7/2/18 translated: the new viral dna and protein molecules then assemble into new phage. 9. 3 bacteria can transfer dna in three ways: there are 3 mechanisms used by bacteria to. 7/2/18 move genes from cell to cell: transformation: it is the uptake of dna from the surrounding environment, transduction: the gene transfer by phages, conjugation: transfer of dna from a donor to a recipient bacterial cell. 7/2/18: once new dna gets into a bacterial cell by any mechanism, part of it may then integrate into the recipient"s chromosome. 9. 4 bacterial plasmids can serve as carriers for gene transfer: the ability of a donor e. coli cell to carry out conjugation is usually due to a specific piece of. 7/2/18: an f factor can exist as a plasmid, a small, circular dna molecule separate from the bacte- 7/2/18: a flu shot, given once an year gives us immunity to flu in subsequent years because influen-
