Lesson 7: Bacterial Morphology and Fine Structure Flashcards
meaning berries, usually round but can either be oval, elongated, spherical or elliptical shape.
cocci
either they may remain as a single cell or may aggregate together for various configurations
cocci
represented by single, discrete round cell
monococcus
divides but the cells remain attached to each other
diplococcus
here the cells are repeatedly in one plane to form chain of cells
streptococcus
this consist of four round cells, which divide in two planes at right angles to one another and remain in group of four.
tetracoccus
here the cells are divided into three planes forming a structured like bunches of grapes giving and irregular configuration
staphylococcus
these cells divide in three planes but but they form a cube like configuration consisting of eight or sixteen cells but they have a regular shape.
sarcina
these are rod shaped or cylindrical bacteria which either remain singly or in pairs.
bacilli
appear in pairs after cell division
diplobacilli
occurs in chain after cell division
streptobacilli
oval shaped similar to cocci
coccobacilli
curved, comma shaped bacteria and represented by a single genus.
vibro
spiral or spring like with multiple curvature and terminal flagella witb fairly rigid bodies
spirilla
helical and flexible which move by means of axial filaments resembling flagella but contained within an external sheath
spirochete
(meaning sugar coat) are viscous substances that surrounds the cell composed of polysaccharide, polypeptide or both
glycocalyx
functions of glycolcalyx
- enables bacteria to survive by attaching
- bacterial source of energy when supply is low
- protection to host cell by attaching to surface
the substance is organized, is firmly attached to the cell wall, and clinically contributes to the virulence (ability to cause disease) of bacteria due to its capacity to evade phagocytosis by hosts cells
capsule form
the substance in unorganized and is loosely attached to the cell wall
slime layer form
(singular: flagellum meaning whip) are long filamentous appendages that propel bacteria
flagella
three basic parts of flagella
filament
hook
basal body
long outermost part that contains flagellin arranged in helix
filament
where filament is attached to
hook
anchors the flagellum to the cell wall and plasma membrane
basal body
the movement, which is can be presented in different pattern
motility
bacterium moves in one direction
run or swim
periodic abrupt or random interruptions to run or swim
tumbles
rapid wavelike movement
swarm
also called endoflagella present in spirochetes like borrelia burgdorferi that causes lyme disease.
axial filaments
are actually bundled fibrils that arise at one end of spirochetes and spiral around it.
filaments
is a type of a protein called pilin.
fimbriae
it is a numerous hair like appendages that surrounds the bacterium and helps to attach to hosts surfaces.
fimbriae
is another type of the protein pilin but is only presented in one or two per bacterium
pili
helps bacterial cell to prepare DNA transfer from one cell to another
pili
is a semi rigid structure protects the interior of the cell from the outside environment
bacterial cell
functions of the bacterial wall
- prevents rupture of the cell
- maintain shape or cell
- anchors flagella
- contributes to the virulence of the bacteria
- site of action of some antibiotics
- the chemical composition of cell is used to differentiate types of bacteria
the bacterial cell wall is primarily composed of network of ___________
peptidoglycan (also called murein)
have multiple layers of peptidoglycan in its cell wall for a thick rigid structure.
gram positive bacteria
provide the antigenic capacity of the bacteria making ot possible to identify it upon laboratory tests.
teichoic acids
has a thin layer of peptidoglycan making it very susceptible to mechanical breakage or environmental degradation
gram negative bacteria
its cell wall (outer portion) is composed of
lipopolysaccharide (LPS, also called endotoxin) lipoproteins and phospholipids
functions of lipopolysaccharide
- evades phagocytosis and cell lysis
- barrier to antibiotics and other enzymes
- passage of molecules thru porin channels
specifically, the LPS functions are;
- provides antigenic capacity of bacteria
- causes physiological effects when present in the bloodstream
causes physiological effects when present in the bloodstream. what are these?
toxicity
sepsis
fever
shock
death
there are bacteria that is composed of higher percentage of
mycolic acid
can be stained with a carbolfuchsin which resist removal with acid alcohol thus called?
acid-fast bacteria
there is also what we call atypical cell walls having no cell or with very little wall material
mycoplasma sp.
composed mainly of phospholipids arranged in two rows
lipid bilayer
Passive Process include
- Simple diffusion
- Facilitated diffusion
- Osmosis
Active Processes include
- Active Transport
- Group Translocation
movement of molecules from high concentration to low concentration
simple diffusion
same with simple diffusion but substances are transported across the membrane via transporter
Facilitated diffusion
movement of a solvent molecule (water) from high concentration to low concentration via selectively permeable membrane.
osmosis
the cells uses energy to transport a substance from lower to higher concentration without altering the substance.
active transport
a special type of active that alters the substance being transported across membrane.
group translocation
located in cytoplasm of a bacterial cell contains double-stranded DNA for the bacterial chromosome and plasmid
nuclear area
the substance inside the plasma membrane composed mainly of water and others substances like proteins, carbohydrates, or lipids
cytoplasm
it is important in gene manipulation of bacteria
plasmid
present in both prokaryotic and eukaryotic cells and serve as sites for protein synthesis
ribosomes
are iron oxide that acts like magnet to move until attachment site
magnetosomes
these are specialized resting cell formed internal the cell membrane when bacterial cell goes into vegetative state in a process called sporulation
endospore
