Chapter 2 Flashcards
Maximum resolution
1 wavelength
spirochetes
microbes that contain axial filament
volutin
an inclusion body
refraction
passage through lens material bends light
resolution
the ability to distinguish two adjacent objects or points from one another
resolving power
also resolution = (wavelength of light in nm)/(2*numerical aperture)
numerical aperture
describes the relative efficiency of a lens in bending light rays
Coccus
Ball Shape
Diplococci
2 ball cocci
streptococci
chained ball cocci
staphylococci
bunched grape cocci
bacillus
rod/pill shaped
streptobacilli
chained pill bacilli
spirochete
squiggly chain
spirillum
thicker spiral chain
vibrio
bean shaped
diffusion
advantage to being small is there is more surface area relative to cell volume. and they grow faster
most common macromolecule in cell
proteins
cell membrane
the structure that defines the existence of a cell
hydrophilic
Head of phospholipid, likes water and polar molecules
hydrophobic
tail of phospholipid in membrane, doesn’t like water or polar molecules
Membrane is made of what?
Phospholipid and proteins
what is a phospholipid?
consists of glycerol with ester links to two fatty acids and a phosphoryl head group
amphipathic
a molecule that contains both polar and nonpolar parts
membrane protein functions
- structural support
- secretion of virulence factors
- transmission of communication signals
- ion transport and energy storage
semi-permeable
The cell membrane is semi-permeable and allows some small, nonpolar molecules through
diffusion
selective transport, allows small uncharged molecules to permeate the membrane
osmosis
the diffusion of water across the cell membrane
hypertonic
water goes into the cell to balance concentration
hypotonic
concentration is low and water will come out of the cell
pH change
weak acids and bases exist in an uncharged form and can diffuse across the membrane
transporters
polar molecules and charged molecules require transport through specific proteins
passive transport
molecules move along their concentration gradient
active transport
molecules move against their concentration gradient (requires energy)
fluid mosaic model
cell membrane has fluidity and can change with the phospholipid head groups and their fatty acid chains.
sterols
cholesterol and ergosterol, reinforcing agents in eukaryotic membranes
hopanoids, reinforcing agents in bacteria
plasmid
extrachromosomal gene to make ribosomes
haploid
asexual in bacteria
nucleoid
contains bacterial DNA
prokaryote ribosomes
in all cells, translates mRNA into proteins, total size 70s
thylakoids
ectensively folded intracellular membranes in phototrophs
carboxysomes
polyhedral bodies packed with the enzyme rubisco for CO2 fixation
gas vesicles
increase buoyancy
storage granules
the storage of nutrients in a cell
Inclusion bodies for energy
Glycogen, PHB, and PHA
magnetosomes
membrane-embedded crystals of Fe3O4 fixation which orient the swimming of magnetotactic bacteria
FtsZ
Shape determining protein that forms a “z-ring” for septum placement
MreB
shape determining protein that forms a coil inside rod-shaped cells
CreS
Shape determining protein, Crescentin, forms and polymer along the inner side of crescent-shaped bacteria
the cell wall
confers shape and rigidity to the cell and helps withstand turgor pressure, Bacteria cell wall consists of single interlinked molecule
peptidoglycan
(murein) makes up most cell calls in bacteria
peptide building blocks for bacteria
long polymers N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) bound to peptide
cross-bridges
formed by peptides to connect the parallel glycan strands
bacterial envelopes
an additional envelope layer that provides structural support and protection
gram-positive bacteria
1 think cell wall (purple stain) contains teichoic acid
Gram-negative bacteria
2 thin cell walls (pink stain)
Lipoteichoic
gram-positive acid linked to lipids and anchors the wall to the membrane
mycobacterial cell envelopes
complex cell envelopes in gram+ that contain unusual membrane lipids (mycolic acids) and unusual sugars (arabinogalactans)
mycolic acids
carboxyl group and two long R chains, long R group=more hydrophobic and acid fast
thin peptidoglycan layer
consists of one or two sheets covered by and outer membrane which has defensive abilities and toxigenic properties on many pathogens (Gram-)
Lipopolysaccharide
outer membrane of gram-
3 sections: lipid A (six fatty acids)
Core (adaptor structure)
O-antigen (repeats)
porin
auto membrane protein that allows small things to pass through
mycoplasm
true bacteria, very small, no peptidoglycan wall, important pathogens, contain cholesterol they dont make
flagellum structure
provides locomotion (electric motor) uses protons to charge movement, contains peptidoglycan (gram -)
monotrichous
1 limbed flagellar
amphitrichous
two limbs on each end
lophotrichous
many limbs on one end
peritrichous
many limbs around whole cell
flagella of spirochetes
axial filaments located between two membranes called periplasm, causes corkscrew movement, better for movement through viscous media
chemotaxis
the movement of a bacterium in respose to chemical gradients
CCw rotation
flagella bundle together to push cell forward (run)
CW rotation
flagellar bundle falls apart and cell “tumbles”
fimbriae
limbs used to attach to other things
pilus
Attached to other bacteria for gene transfer
capsule
a polysaccharide that evades phagocytes
