Ch.4 Functional Anatomy of Bacteria

Spherical “berries”

Coccus

Rod-shaped; “little staffs”

Bacillus

What are the 4 types of basic shapes of prokaryotes?

Coccus, bacillus, coccobacillus, spiral

What are the 3 types of spiral prokaryotic shapes?

Vibrio, Spirillum, Spirochete

Spiral; curved rods

Vibrio

Spiral; rigid corkscrew

Spirillum

Spiral; flexible corkscrew

Spirochete

What does prokaryotic cell arrangements depend on?

Plane of division

With bacilli, how many planes of division are possible?

1

From A to D

Bacillus, diplobacilli, streptobacilli, coccobacillus

With cocci, how many planes of division are possible?

Multiple

Diplococci; streptococci

B to D

Tetrad; sarcinae; staphylococci

“Sugar coat” outside of cell wall; thick, sticky polymer made of polysaccharides

Glycocalyx

Two main roles of capsules

Prevent phagocytosis, formation of biofilm

Neatly organized and firmly attached glycocalyx

Capsule

Unorganized and loosely attached glycocalyx

Slime layer

Long filaments, propel bacteria. Not membrane bound. Made of flagellin. Made of a basal body, hook, and filament

Flagella

Can allow us to distinguish between serovars (variations within a species) of gram-negative bacteria

H antigen (flagellar protein)

The name for cells with no flagella

atrichous

The name for when flagella all over cell; “Perimeter”

Peritrichous

When flagella at one or both ends of the cell

Polar

A polar cell with a single flagellum at one pole

Monotrichous

A polar cell when a tuft of flagella is at one pole

Lophotrichous

A polar cell when flagella at both poles

Amphitrichous

How does the flagella move?

Rotation of basal body; runs and tumbles

What are the two types of stimulus for flagella motility?

Chemotaxis and phototaxis

Endoflagella; in spirochetes; made of flagellin; bundles of fibrils that spiral around the cell

Axial filaments

Made up of pilin, allow attachment to other bacteria (biofilm formation)

Fimbriae

Made of pilin, twitching motility (grappling hook model); conjugation from one bacteria (F+) connects to receptors on another bacteria (F-)

Pili (conjugation pili)

What are the two disaccharides peptidoglycan is a polymer of?

NAG & NAM

Alternating NAM and NAG molecules are linked in _____ to form carbohydrate backbone

Rows

Adjacent rows of NAM/NAG are linked by polypeptides form what?

Tetrapeptide and cross-bridge amino acids

Gram+ cell wall contain what? Negatively charged molecules

Teichoic acids (alcohol + phosphate)

Strong negative charge, protection from host defenses, susceptible to breakage, contains porins, outer leaflet contains lipopolysaccharide (LPS)

Gram negative outer membrane

What does the lipopolysaccharide (LPS) consist of?

Lipid A, Core polysaccharide, O polysaccharide

Endotoxin released when the cell bursts

Lipid A

Structural stability part of LPS

core polysaccharide

part of LPS; Antigen to distinguish species/strains

O polysaccharide

Very small bacteria, no cell walls. Their plasma membrane has sterols

Mycoplasma (only plasma membrane)

Mycolic (waxy) acid bound to peptidoglycan

Acid-fast bacteria cell walls (mycobacteria)

How does lysozyme affect gram positive cells?

Digests outer cell wall

How does lysozyme affect gram negative cells?

add chemical to disrupt outer membrane then lysozyme can digest cell wall

After lysozyme does its job, what could happen to both types of cells?

Osmotic lysis (burst in water)

What inhibits peptide cross bridges in peptidoglycan?

penicillin

The 3 types of movement of material that does not require energy/goes down/with a [ ] gradient?

simple diffusion (O2, CO2), facilitated diffusion (glucose), osmosis

the movement of water across a selectively permeable membrane from an area of high water concentration to an area of lower water concentration

Osmosis

Movement of material that goes against [ ] gradient/requires energy?

Active transport, group translocation

Substrate is chemically altered during transport across the membrane, can’t return across the membrane

Group translocation

What is the size of the prokaryotic ribosome?

70S (50S + 30S subunits)

Reserve substances; used as energy reserves

Inclusions

inclusions of iron oxide- act like magnets (may help bacteria orient themselves

Magnetosomes

Dormant, highly durable dehydrated cells; only in bacillus and clostridium species

Endospores

Endospore formation induced by scarcity of key nutrient (starvation)

Sporulation

Return to vegeatative state; triggered by damage to endospore coat

Germination