Lecture 6 Flashcards
Where does Bt toxin come from? What is it
-Bacillus thuringiensis
-bacteria that lives in soil
-forms endospores and makes endotoxins
What is an endospore?
-dehydrated cells w/ thick walls and additional layers internal to cell membrane
-reistant to heat, UV, chemicals, desiccation
-form when nutrients are depleted/bad environment
Sporulation
-process in which endospores form
-starts w/ SpoA when phosphorylated
Explain cannibalism in sporulating cells
When nutrients are scare, a group that is ready to form endospores will lyse cells that are not ready to form endospores and use their nutrients as energy to form endospores
What is Skf
Sporulation killing factors
-lyse cells for nutrients for endospore formation
What is Sdp
Sporulation delaying proteins
Which form is the DNA in vegetative cells?
B form
What is dipicolinic acid and where is it located?
Used for dehydration
-binds to calcium
-located inside endospore
What are SASPs and where are they located?
proteins that protect against UV and are an energy source during spore germination
-located inside endospore
What form are endospores in and why?
A form
-need to be as compact as possible since no transcription/dormant
True or false: Bacteria & Eukaryotic DNA both have the same bases (A, T, C ,G) are double stranded and anti-parallel
True
Describe bacterial DNA
-circular DNA
-not surrounded by a nuclear membrane
-no histones can have HU & H-NS
Describe eukaryotic DNA
-Nulceosomes w/ histones
-chromatin & chromosomes
What is the role of a promoter
DNA sequence that is upstream of the transcription start site
-RNA pol binds and starts transcription
What is the specific sequence in the mRNA where ribosome begins translation?
Ribosome binding site
True or false: Transcription and translation does not occur at the same time in bacteria
False
-In bacteria transcription and translation are coupled (happen at the same time)
True or false: Transcription and translation occur spatially and temporally in eukaryotes
True
Partitioning proteins
Move plasmids during cell division
In vitro (in lab) a plasmid present in a bacteria cell is easily transferred or easily lost?
Easily lost (not transferred) during cell division w/out a selection marker in the medium that is diff than the one in the plasmid
Why is agrobacterium used in corn?
-will pass the cry gene to corn via HGT
-T DNA–>scientists can modify them
-does not cause tumors in corn
How does kanamycin affect corn
Endosymbiotic theory
-mitochondria and chloroplasts still have something similar to 30S subunit
-used as a selective marker since it does not directly affect plant cells
