Chapter 6 Flashcards
auxotrophs
bacterial strain that has a nutritional requirement
mutant type-shown by superscript -
heterotrophs
bacterial strain that requires an organic form of carbon from another source
characteristics of prokaryotic plasmids
- contains small assortment of supplementary genes
- usulay transferred thru sex pilus
- replicates independently of prokaryotic fission
- used as a vector in biotechnology
- circular
- made of nucleotides
characteristics of prokaryotic chromosomes
- located in nucleoid region
- pulled to opposite poles during prokaryotic fission
- cell’s primary DNA molecule
- circular
- made of nucleotides
plasmid definition
extra pieces of DNA that are not essential for survival
conjugation definition
union of 2 bacterial cells for the transfer of DNA from the donor cell to the recipient through a sex pilus
F- bacterium
- does not contain F factor
- recipient of DNA during conjugation
F+ bacterium
- contains F factor
- donor of DNA during conjugation
F’ bacterium
- contains plasmid with the F factor and some genomic DNA
- this new sequence can then be transferred to another bacterium
Hfr bacterium
- bacteria with F factor integrated into genome
- can also donate genes into F- bacterium
generalized transduction
- mediated by phages (vectors)
- phage attached to outside of cell and injects its DNA into it
- causes the host cell to lyse
protoptrophs
wild type of bacteria
autotrophs
bacteria that can do photosynthesis in order to make their own food
transformation
free DNA is taken up by a pump in the wall of a cell
specialized transduction
a specific part of the host DNA is inserted into the viral DNA
-lysogenic response
steps of bacterial transformation
- DNA binds to the DNA-binding complex
- enzyme dissociated the DNA into single strands
- single stranded DNA fragment is imported into cell
- DNA recombines into a region of the bacterial chromosome
- foreign DNA is duplicated with bacterial DNA after the next round of cell division
steps of transduction
- phage binds to bacterial surface
- phage injects viral DNA into host cell
- bacterial DNA is degraded into small fragments
- phage DNA is replicated and new phage coat proteins are synthesized
- phage coat proteins enclose bacterial DNA
- host bacterial cell lyses
- bacterial DNA is injected by a phage into a new bacterium
characteristics of lytic cycle
- bacterial cell wall is broken down causing lysis of the host cell
- host DNA is degraded
characteristics of lysogenic cycle
- bacterial genome contains the integrated phage genome
- phage genome replicates with host DNA
- causes no damage to host cell
- integrated phage becomes prophage
cistron defintion
a complementation group defined by a cis-trans test
- smallest functional unit of heredity
- also know as gene
bacteriophage plaque definition
a visible region of infection-induced lysis of bacterial cells
