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81 Cards in this Set
- Front
- Back
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Shapes of some prokaryote: cocci
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cocci- spherical
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Shapes of some prokaryote: bacilli
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bacilli- rod-like
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Shapes of some prokaryote: vibrios
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vibrios- comma-shapped
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Shapes of some prokaryote: spirilla
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spirilla-spirals
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Shapes of some prokaryote: spirochete
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spirochete- cork screw
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Shapes of some prokaryote: pleomorphic
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Doesn't have a definitive shape, generally has no cell wall
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When individual cells can stick together after dividing to form a pair it is refeered to as?
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diplo- an example would be diplocoucus
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When individual cell stick together after dividing to form a chain, they are generally referred to as?
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Strepto, genus is named after what it looks like
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When individual cell stick together after dividing to form grape-like clusters?
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Staphylo
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When individual cell stick together after dividing to form a chain with branches?
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Filaments are just a chain with branches
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Some cells shape: vibrio cholerae, which looks like what and causes what?
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comma shaped, causes cholera
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Some cells shape: Rhodospirillum rubrum, which looks like what and causes what?
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red and spiral shaped, shaped as a spirilla
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Some cells shape: Leptospira interrogans, which looks like what and causes what?
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looks like a tight spiral and is a type of spirochete
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Some cells shape: Actinomyces, which looks like what and causes what?
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Filamentous
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Some cells shape: Haloquadratum walsbyi, which looks like what and causes what?
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comes from a shape meaning its square or rectangles, Halo refers to high salt environment. From the phylum archaea
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What is the cell wall made of?
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murein, a type of peptidoglycan
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Gram-negative bacteria's membrane is different from gram-positive how?
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Gram-negative bacteria have also an outer membrane (OM) and periplasmic space (space between CM and OM)
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What are hopanoids?
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Hopanoids are the cholesterol of bacteria, they act as a fluidity buffer
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How is fluidity of the cell membrane determined?
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By the level of saturation of the fatty acids – at a given temperature the greater the number of double-bonds (how unsaturated), the more fluid the membrane (because more double bonds, more kinks, less cozy)
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What is the structure of murein?
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Murein consists of alternating layers of NAG and NAM
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How are each NAM arranged in the murien layers and what peptidase connects them?
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• Each NAM has an attached short peptide (5 amino) that may be cross-linked to another NAM short peptide on an adjacent layer (transpeptidase)
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What does that crosslinking of NAM in murein provide of gram-positive baceria?
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You need the interbridges to provide fluidity and lessen stiffness
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Gram positive bacteria uses crosslinkin of what form of Alanine to link to glycine creating what that allows linkage to L-Lysine
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Gram positive bacteria use D-Alanine to link glycine creating a glycine interbridge that connects to L-Lysin
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In gram-negative bacteria how are inter-bridges of NAM in Murein different?
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Gram-negative bacteria does not use interbriges, they use DAP (diaminopimelic acid) linked to D-Alanine and have much fewer layers
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What is the layers difference between Gram-positive bacteria vs gram-negative bacteria, of NAM in Murien and cross-linking between D-Ala?
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Gram Positive have a layer 20-80 nam, Gram negative are much smallers being 2-7 nm thick
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Gram positive walls have structures that are long strings of glycerol attached covalently the cytoplasmic membrane?
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Teichoicacids, which give an overall negative charge but other than that the function is unclear
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What is a major component of the gram-negative outermembrane?
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Lipopolysaccharaide (LPS) is major component of OM
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What is the lipopolysacchararide, the major component of GN OM, comprise of?
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Lipida A, core polysacharides and O antigens
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Lipid part of the lipopolysaccharide, the major component of the GN OM is responsible for what?
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Lipid (aka an endotoxin is responsible for septic shock associated with Gram-bacterial infections
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Why is the OM much more permeable to solues than the plasma membrane (PM)?
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the presence of porrins which allow in anything less than 700 MW
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S layers are the outermost layers in the envelopes of what species?
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Bacteria and Archaea, and Gram positive and Gram negative
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What do S layers take the place of in Archaea?
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Cell Walls
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What is an S-layer?
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self-assembling, crystalline structure of a single protein or glycoprotein
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What do some microbes, like Campylobacteria, use S layers for?
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S-layers can be used as shields against the immune system, can be found in undercooked meats
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Capsules and slime layers are extracellular structures, meaning they are ... andd are compose of high...
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non-evelope structures, compose of high MW polysaccharide or polypeptide
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What are capsules or slime layers used for?
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Used for attachment, protection from the immune system, or for protection against desiccation
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What are slime layers important factors in?
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Virulence factors (how well this microbe spread disease)
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What is a glycocalyx layer?
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a region of slime found between organisms
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Archaea are different the murein membranes of bacteria in that?
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they are closer related to gram positive than gram negative, but they are non-murein variable in structure
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Archaeal cytoplasmic membranes are different from bacteria as the branched lipids are derived from what?
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isoprene that are ether-linked to glycer phosphates, there are no LPS in gram-negative archaea
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What happens to the membrane of hyperthermophiles (thermoplasma) as temperatures increase?
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As temperatures increase lipid bilayers that contain C40 monolayers, (which are stable at high temperatures) can slide past each other so that it creates one layer
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What are the two major prokaryotic appendages?
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Flagella and Pili
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Flagella can be defined as:
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The most common form of prokaryotic directed motion, used for chemotaxis (movements towards or away from certain molecules)
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Pili (AKA Fimbriae) can be defined as:
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Pili are mainly used for adhesion, but they may be used along with slime production to create a type of twitching motility (non-directed) on solid surfaces in a few microbial species
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What are three types of Flagella?
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Monotrichous polar, Lophotrichous, Peritrichous
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What is monotrichous polar flagellation?
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one flagella at the end (or either pole) of cell
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What is Lophotrichous flagellation?
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Lophotrichous flagellation have a tuft of flagella at the end of one cell
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What is Peritrichous flagellation?
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Peritrichous flagellation have flagella all around the cell
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What do flagella look like?
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They are semi-rigid, multi-component structures found in both Gram-positive and gram-negative cells
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How are flagella anchored in prokaryotes?
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Flagella are anchored by rings that assemble in each layer of the cell envelope (basal body)
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How are flagella are assembled?
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Flagella are assembled from inside to outside via hollow internal tube-like structures, it is made of subunits that travel through the tube to get to the end
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How do flagellated cells move?
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Each flagella is semi-rigid and movement occurs by turning whole structure (like a Propeller mechanism
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When flagellated cells move they need to work a propellor, how do they generate torque?
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Torque is generated by moving hydrogen ions into cell (creating PMF) using Mot (or motor) proteins by interacting with positive negative charges
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Which direction does flagella travel in?
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Rotation of flagella can be either clockwise (CW) or counterclockwise (CCW) and can be reversed by Fli proteins
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When flagella changes direction it causes...
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tumble
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What triggers the movement of flagella?
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Movement of flagella is triggered by cocnentration of repellents or attractants in the environment (for chemotaxis), but can be triggered by light or ph
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Endoflagella of spirochetes are a little different though, they work how?
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Axial filaments(flagella) wraps around the cell within the periplasmic space, when the flagella rotates, it moves the spirochetes forward in a corckscrew fashion, allowing them to invade into tissues and cause disease
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What do pili or fimbriae look like?
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short, filamentous surface structures, usually in gram-negative microbes
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These short filamentous surface pili/fimbriae are ued for what?
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Attatch to substrata, other microbes or sex pili
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What is a biofilms?
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A biofilm is a bunch of pili attatch microbes allowing them grow in a community
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What else can pili be involved in?
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Can be part of non-directed crawling motion called twitching motility, but typically pili are not involved in locomotion
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What is a nucleoid?
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A non-rigid structure that has a chromosome that is condense inside, this is where transcription and translation occur
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Plasmids are essentially?
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the x gene of prokaryotes
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What are plasmids?
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Extra-chromosomal circular DNA that replicate autonomously in the cytoplasm, not linked to replication of overall cell
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What is the function of a plasmids?
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Generally have auxillary functions; that used in conjugation, carry resistance to antibiotics, function the microbes to be better at causing disease or contain extra growth pathways
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Where do you find prokaryotic ribosomes?
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prokaryotic are packed into the prokaryotic cytoplasm
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How are prokaryotic ribosomes different from eukaryotic ribosomes?
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Prokaryotic ribosomes are 70 S consisting of two subunits, they are functionally similar but structurally different eukaryotic 80S ribosomes
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What is important to remember about prokaryotic and eukaryotic ribosomes when using antibiotics?
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Eukaryotic cells contain prokaryotic-type ribosomes in mitochondria & chloroplasts, So if use prokaryotic killing type antibiotic must make sure can’t get into eukaryotic membrane or will hurt wrong cells
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The prokaryotic cytoskeleton function to do what?
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Cell division, protein localization and cell shape determination
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What are gas vesicles, that are found in both Bacteria and Archaea?
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Purpose is to confer buoyancy (not storage), ( by being impermeable to water, but permeable to gas), they are usually found in photosynthetic organisms, so can float to the perfect spot in the water to photosynthesize, they vary in number from several to several hundred, also vary in size
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What are some membrane delineated structures that have specific structures in the cells or cell inclusions?
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Storage granules, inclusion bodies, carboxysomes, and magnetosomes
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What is PHA storage?
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PHAs (polyhydroxyalkanoates) are commonly formed and used for storage of excess organic fuel molecules
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The most common form of PHA storage is?
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PHB (poly-b-hydroxygluterate) these microbe often will convert whatever to PHA so they can put in storage
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What are magnetosomes?
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Particles containing Fe3O4 or Fe3S4 work as magnets and allow cells to align along earth’s magnetic pole
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What are "somes"?
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membrane delineated structure that works in concentrations
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Define: Carboxysomes
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groupings of enzymes that fix CO2
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Define: Enterosomes
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(something occurring living in intestine) contain high levels of specific enzymes involved in special metabolic pathways in gut (enteric) bacteria
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How many species use Endospores?
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Not a whole lot
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What is endosporulation and when does it happen?
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(process of producing an endospore) occurs when times get tough and cell cannot survive, so it goes dormant
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Describe an endospore?
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Endospores are resistant to desiccation, heat, radiation and chemicals and may survive for centuries or longer
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What do endospores contain?
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High levels of Ca to replace Magnesium, dipicolinic acid to manage the calcium; SASPs (small, acidsoluble proteins) that bind and make DNA inert, incredible low amounts of H2O
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