CH. 3

• bacterial shapes


  cocci, rods, spiral, mycelia, and pleomorphic
• bacterial size


  average is 1 x 2-6; smaller is better because of surface to volume ratio, predation, and nutrient uptake
• cell envelope(B)


  includes plasma membrane, cell wall, and layers outside the cell wall (capsule, e.g.)
• cell membrane(B)


  phospholipid bilayer made of fatty acids, glycerol, and hapenoids (philic heads, phobic tails); uptakes nutrients
• diffusion


  high concentration to low concentration
• active transport


  against the gradient flow, uses ABC transporters and ATP as energy
• translocation


  chemically modified when passing through membrane (PTS)
• siderophores


  secreted by micros to aid in iron uptake; bonds with ferric acid
• cell walls(B)


  maintains shape, protects, and divides; made of peptidoglycan (rigid mesh)
• peptidoglycan


  consists of two alternating sugars (NAM, NAG), and alternating D amino acids and L amino acids; helical in shape and crosslinked for strength
• fluid mosaic model


  defines cytoplasmic membranes as lipid bilayers with floating proteins
• gram-positive cells


  thick peptidoglycan cell wall with techoic and lipotechoic acids, plasma membrane
• gram-negative cells


  outer membrane of lipids, lipoproteins, and LPS; small peptidoglycan cell wall with no techoic acids, plasma membrane
• lipopolysaccharides (LPS)


  consists of lipid A embedded in the outer membrane and O side chains sticking out; acts as protection, an endotoxin, and creates a negative charge on the cell surface
• hypotonic


  less h2o outside, water moves in
• hypertonic


  more h2o outside, water leaves
• isotonic


  only survivable environment for cells with no cell wall; protoplasts, schleroplasts, and mycoplasma
• glycocalyx


  aid in attachment to surfaces like a biofilm; capsules, slime layers, S layers, etc
• capsules


  composed of polysaccharides and are not easily removed; resistant to phagocytosis, viruses and detergents
• s-layers


  structured proteins that self-assemble to protect from fluctuations, enzymes, and predation as well as maintain shape and promote adhesion; adhere to outer membrane in gram-negative, associated with cell wall surface in gram-positive
• cytoskeletons


  tubulin homologs (FtSz for cell division), actin homologs (MreB maintins shape), filament homologs (CreS maintains curved shape), and unique bacterial cytoskeleton proteins
• intracytoplasmic membranes


  infoldings in photosynthetic bacteria, or anammoxosome in plantomycetes for ammonia oxidation
• inclusions


  granules of stockpiled materials; can be storage for nutrients, microcompartments for specialized functions, gas vacuoles and magnetosomes in aquatic bacteria
• carboxysome


  a type of microcompartment
• ribosomes(B)


  protein/RNA structures that are the site of protein synthesis; 70s for bacteria (16s in small subunit, 23s and 5s in large subunits) and 80s for eukaryotes
• nucleoid(B)


  location of chromosome and proteins, 1 DNA molecule; usually has no membrane
• plasmids


  extrachromosomal DNA that exist and replicate independently, contain few genes that are non-essential like drug resistance
• fimbrea / pili(B)


  hair-like appendages for motility, DNA uptake, and conjugation
• flagella(B)


  for movement, can be mono, polar, amphi, lopho, or peri
• endospores


  dormant structures with core of nucleoids and ribosomes; created through sporulation and resistant to environmental factors through calcium, spore coat, exosporiums, and SASPs