endospore Flashcards
what is an endospore
a form of specialized resting cell
where are endospores found (what type of organism)
gram positive bacteria (ie ones in the soil)
T or F: endospores are found in gram negative bacteria only
false; gram positive bacteria only
when does an endospore form
when conditions become unfavourable to the bacteria
T or F: the endospore is a very resistant structure
true
list some conditions that may cause an endospore to form
extreme heat, lack of water, toxic chemicals, radiation
what staining procedure do we do to view an endospore
shaeffer-fulton procedure (ie endospore stain)
what dyes do we use in an endospore stain
malachite green and safranin
what special thing do we need to do during an endospore stain
use steam!
describe the color results of the endospore stain
endospore = green, cytoplasm = red
what would happen if we did simple staining on an endospore
it would be clear and wouldn’t retain the dye
describe the 4 different locations that an endospore can be located within the cell
centrally, subterminally, terminally, or terminally w/ a swollen end
what is the innermost part of the endospore
the core
what does the core of the endospore contain (that aren’t the special elements)
nucleoid, ribosomes, and other essential elements
what two special elements does the core contain
dipicolinic acid complexed with Ca2+, and small acid-soluble proteins (SASPs)
describe the function of dipicolinic acid
binds to water and helps to dehydrate the endospore. It also complexes with DNA and stabilizes it against heat denaturation
describe the function of small acid-soluble proteins (SASPs)
binds DNA and protects against UV radiation, dessication, and dry heat. It also serves as a carbon and energy source during the “outgrowth stage”
what surrounds the core
inner membrane
what surrounds the inner membrane
germ cell wall
what is the germ cell wall of the endospore made of
peptidoglycan
what surrounds the cell wall
the cortex
what is the cortex made up of
peptidoglycan
what surrounds the cortex
outer membrane
what surrounds the outer membrane
spore coat
what is the spore coat made up of
many different proteins
what surrounds the coat
the exosporium
what is the exosporium made up of
a thin layer of protein
T or F: all spores contain an exosporium
false; not all spores have it
what cell does the endospore form within
the mother cell/vegetative cell
what is another name for the mother cell
sporangium
how long does endospore formation take
8-10 hours
what is the name for endospore formation
sporulation or sporogenesis
sporulation step 1
chromosome replicates, PM starts to invaginate and isolate the new DNA + small portion of cytoplasm
sporulation step 2
PM starts to surround DNA, cytoplasm, and membrane that was isolated in step 1
sporulation step 3
immature endospore is now surrounded by 2 membranes
sporulation step 4
peptidoglycan layer forms between the membranes
sporulation step 5
spore coat forms around the outer membrane, endospore is now fully mature. Lytic enzymes are released that break down cell wall of the mother cell and the PM breaks open
sporulation step 6
endospore is freed from the mother cell, and now it is called a spore
what do we call an endospore once it’s freed from the mother cell
a spore
what is germination
the process in which an endospore returns to its vegetative state
T or F: an endospore carried out metabolic reactions
false; it doesn’t carry out any metabolic reactions
T or F: an endospore may remain dormant for thousands of years
true
how long might an endospore remain dormant for
thousands of years
name the 3 stages of germination
activation, germination, outgrowth
describe activation of germination
heat treatment occurs which prepares the spore for the next step
describe germination
endospore’s dormant stage is broken and dipicolinic aicd-Ca is released from the DNA. peptidoglycan in the cortex is broken down, leaving only the peptidoglycan in the cell wall. Water moves into the core. Metabolic reactions now occur
describe outgrowth of germination
cell breaks free from the broken spore and begins to grow, and now we have a bacterium being released
T or F: endospore production is used for reproductive purposes
false; sporulation is NOT reproduction
explain why sporulation is not the same as reproduction
we started with one bacterium, it made an endospore, endospore stayed dormant, and when conditions become good it become a bacteria again via germination. No new bacteria is being made
