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tetrads

cocci that divide in 2 planes - groups of 4

sarcinae

cocci divide in 3 planes - group of 8

.2-2. um diameter;
2-8 um length

prokaryote size

vibrios

curved rods; like comma

spirilla

have a distinctive helical shape like corkscrew, rigid bodies;
move by flagella

spirochetes

helical, flexible;
move by axial filament

Haloarcula

genus of square shaped cells

Stella

genus of star shaped cells

pleomorphic

have many shapes

Rhizobium;
Corynebacterium

ex of pleomorphic bacteria

glycocalyx/extracellular polymeric substances (EPS)

general term used to describe substances that surround bacterial cells - around cell wall;

gelatinous polymer of polysachharide, polypeptide or both

composition of glycocalyx

slime layer

if glycocalyx is unorganized and loosely attached to cell wall

capsule

if glycocalyx is organized and firmly attached to cell wall

virulence

degree to which a pathogen causes disease

virulence

capsules confer bacterial ___

phagocytosis and dehydration

capsules prevent

substrate attachment

capsules allow for

flagellum

long filamentous appendages that move bacteria

monotrichous

single polar flagellum

amphitrichous

single flagellum at both poles

lophotrichous

2 or more flagella at one or both poles of the cell

peritrichous

flagella distributed over the entire cell;
ex E. coli

Filamnet, hook, basal body

3 basic parts of flagellum

filament

long outermost region of flagellum which is constant in diameter and contains the globular protein flagellin;
not covered by membrane or sheath

flagellin

globular protein in prokaryote Flagellum

hook

structure to which the filament (of flagellum) is attached

basal body

anchors the flagellum to the cell wall and the plasma membrane;
-composed of central rod inserted into a series of rings

2 pairs

gram - have ___ # of rings

outer pair of rings in cell wall, inner pair of rings in plasma membrane

arrangement of basal body rings in gram - bacteria

only inner pair of rings in plasma membrane

arrangement of basal body rings in gram + bacteria

rotation of basal body

allows for movement of flagellum - either clockwise or counterclockwise

undulation

Eukaryotic flagella movement

run or swim

when a bacterium moves in one direction for a period of time

tumble

abrupt, random changes in direction caused by a reversal of flagellar rotation

taxis

movement of a bacterium towards or away from a perticular stimulus

phototaxis

stimulus is light

chemotaxis

stimulus is chemical

axial filaments/endoflagellum

bundles of fibrils that arise at the ends of the cell beneath the outer sheath and spiral around the cell;

Treponema pallidum

causative agent of syphilis

axial filaments

used for locomotion by spirochetes such as Treponema pallidum;
corkscrew motions

pili

hair-like appendages attached to bacterial cells-shorter than flagella

pilin

pili consist of this protein

pili

many gram - bacteria have this

common pili/fimbriae

allows a cell to adhere to surgaces

sex pili

join bacterial cells to allow transfer of DNA from one cell to another

conjugation

bacterial sex

cell wall

complex, semi rigid structure surrounding cell membrane

prevent rupture of bacterial cell;
maintain shape of bacterium;
point of anchorage for flagella;
produce symptoms of disease - some species

fx of cell wall

disaccharide + polypeptide

peptidoglycan

N-acetylglucosamine;
N-acetylmuramic acid

disaccharide of peptidoglycan composed of

NAM

tetrapeptide side chain attach to __

peptide cross bridge

parallel tetrapeptide side chains may be linked by a

alternating NAG and NAM

make up carbohydrate backbone of peptidoglycan

teichoic acid

consists of an alcohol (glycerlol) and phosphate; contained by gram + bact. ;
-have negative charge do to phosphate

regulate cation mvmnt in and out of cell;
pretent extensimve wall breakdown and cell lysis;
provide antigenic specificity

fx of teichoic acids

periplasmic space

gel-like fluid space where peptidoglycan layer resides in gram - bacteria

lipoprotein

peptidoglycan of g- interacts with __ in outer membrane

lipoproteins; lipopolysaccharides; phospholipids

outer membrane of g- bacteria consist of

lipid A (endotoxin)

is toxic in host blood, caused fever and shock - part of lipopolysaccharide

O polysaccharides

fx as antigens which can identify species of bacteria

phospholipids

part of outer membrane -strong neg charge held evade phagocytosis

porin proteins

proteins on outer membrane- non specific < 800 mw can enter

bacteriocin

proteins produced by some bacteria to kill closely related species
-attach to outer membrane proteins on specific channel proteins

Mycoplasma

have no cell walls- do have unique plasma membranes which contain sterols to protect cell from osmotic lysis - usually found in eukaryotes

lysozyme

catalyzes the hydrolysis of bonds between the NAG and NAM sugars of the peptidoglycan layers-destroying cell wall

protoplast

wall less gram + cell

spheroplast

gram - outer membrane and remaining cell

polymyxins

antibiotics that disrupt the phospholipids, thus destroying the cell wall

thylakoids

pigments and enzymes for photosynthesis are found in the ___ of plasma membrane

group transloctaion

like active transport but substance is chemically altered during transports;
-only in prokaryotes

bacteria plasma membrane

involved in ATP production;
contain enzymes which break down nutrients

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