THE MICROBIAL WORLD:

MONERA

: BACTERIA & ARCHAEOBACTERIA

PROTISTA

: UNICELLULAR OR COLONIAL EUCARYOTES THAT LACK TRUE TISSUE.

FUNGI

: EUKARYOTIC ORGANISMS WITH ABSORPTIVE NUTRITION & OFTEN MULTI-CELLULAR.

ANIMALIA

&

PLANTAE

ARE NOT STUDIED BY THE MICROBIOLOGIST.

VIRUSES: ACELLULAR/ NON-LIVING

SIZE, SHAPE & ARRANGEMENT OF PROCARYOTIC CELL BACTERIA VARY IN THEIR SIZE LARGEST VIRUS (POX VIRUS). FROM: MYCOPLASMA (LACK CELL WALLS AND ARE THE SMALLEST ORGANISMS CAPABLE OF INDEPENDENT REPRODUCTION) TO THOSE APPROX. THE SIZE OF THE

SIZE, SHAPE & ARRANGEMENT OF PROCARYOTIC CELLS BACTERIA (PROCARYOTES) COME IN A VARIETY OF SHAPE: SPHERES (COCCI), RODS (BACILLI), CURVED RODS (VIBRIOS), RIGID HELICES (SPIRILLA), FLEXIBLE HELICES (SPIROCHETES), LACKING A SPECIFIC CHARACTERISTIC FORM VARIABLE SHAPE (PLEOMORPHIC, E.G., CORYNEBACTERIUM).

Bacillus anthrax Diplococcus S. pneumoniae staphylococcus Bacillus w/spore Tetanus bacillus Diplococcus gonorrhea Vibrio, e.g., cholera Club-shaped bacillus diphtheria Streptococcus Spirilla, Rigid + flagella Streptobacillus Sarcinae/packet of 8 Cube-like Spirocheted Rigid/ no flagella

SIZE, SHAPE & ARRANGEMENT OF PROCARYOTIC CELL ARRANGEMENT: BY REMAINING ATTACHED AFTER REPRODUCTION BACTERIA MAY HAVE CHARACTERISTIC ARRANGEMENTS: CHAINS (E.G., STREPTOCOCCUS); CLUSTERS (E.G., STAPHYLOCOCCUS); SQUARE PLANAR CONFIGURATION (TETRADS); CUBIC, PACKAGES OF EIGHT CELLS, CONFIGURATION (SARCINAE).

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

TO OBSERVE BACTERIA, THEY MUST BE STAINED

STAINING & FIXATION PRESERVE FINE STRUCTURE OF ORGANISMS.

FIXATIES INCLUDE HEAT OR CHEMICALS (ETHANOL, GLUTERALDEHYDE, MERCURIC ACIDS) FIXATIVES BIND TO MACROMOLECULES TO RENDER THEM INSOLUBLE, INACTIVE & IMMOBILE.

STAINS ACIDIC: HAVE IONIZING GROUPS (COOH) NEGATIVE CHARGES; BIND TO POSITIVELY CHARGED CELL STRUCTURES.

BASIC: HAVE POSITIVE CHARGES; BIND TO NEGATIVELY CHARGED GROUPS ON CELL STRUCTURES.

PROCARYOTIC CELL ORGANIZATION & STRUCTURE OBSERVATION OF BACTERIA REQUIRE SEVERAL STAINING TECHNIQUES : SIMPLE STAINING TECHNIQUES SINGLE DYE TO ENHANCE THE CONTRAST OF THE SPECIMEN AGAINST THE BACKGROUND.

DIFFERENTIAL STAINING DIVIDES BACTERIA INTO DIFFERENT GROUPS BASED ON STAINING PROPERTIES, e.g., GRAM STAINING ACID FAST STAINING SPECIAL STAINING TECHNIQUES STAINING FOR SPECIFIC STRUCTURES. STAINS HAVE AFFINITY FOR CELL STRUCTURES THEY HIGHLIGHT STRUCTURES AS STAINED COMPONENTS (POSITIVE STAINS) ENDOSPORE STAINING GRANULE STAINING VS.

NEGATIVE STAINING - CELLS ARE LIGHT AGAINST A DARK BACK- GROUND (E.G., STAIN WITH INDIA INK) - CAPSULE STAINING FLAGELLA STAINING

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE NEGATIVE STAINING TO OBSERVE CAPSULE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE THE CYTOPLASMIC MEMBRANE IS MADE UP OF AMPHIPATHIC LIPIDS IN A BILAYER AND IS SIMILAR TO THAT OF THE EUCARYOTIC CELL. IT IS: A SELECTIVELY PERMEABLE MEMBRANE LOCATION OF METABOLIC ENZYMES & TRANSPORT PROTEINS SITE OF RESPIRATION LIPID SYNTHESIS AND PHOTOSYNTHESIS PROTEINS THAT ALLOW CELLS TO DETECT AND RESPOND TO CHEMICALS RESIDE IN THE MEMBRANE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE CELL ENVELOPE = OUTER COVERING OF PROCARYOTES & MADE UP OF PLASMA MEMBRANE + CELL WALL + OUTER MEMBRANES (GRAM NEGATIVES) PLASMA MEMBRANE SELECTIVELY PERMEABLE BARRIER - PROVIDES STRUCTURAL INTEGRITY TO BACTERIA LACKING CELL WALL (E.G.,

MYCOPLASMA)

- SIMILAR IN COMPOSITION TO EUCARYOTIC MEMBRANE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE AMPHIPATHIC MOL: HYDROPHILIC POLAR GROUP + HYDROPHOBIC NON-POLAR CHAIN

PROCARYOTIC CELL ORGANIZATION & STRUCTURE CELL WALL MAINTAINS CELL SHAPE AND CONFORMATION - RIGID, COMPLEX INFLEXIBLE LYER EXTERNAL TO CELL MEMBRANE - ENABLES CELLS TO SURVIVE IN HYPOTONIC ENVIRONMENTS - CELLS LACKING CELL WALL (

MYCOPLASMA)

COMPENSATE WITH STEROL CONTAINING PLASMA MEMBRANES - CELL WALLS ARE NOT UNIQUE TO BACTERIA (PLANTS = CELLULOSE ; FUNGi= CHITIN ). BACTERI CELL WALL MADE UP OF POLYSACCHARIDE CALLED PEPTIDOGLYCAN OR MUREIN - ONE TO SEVERAL LAYERS THICK - MADE UP OF REPEATING UNITS OF TWO CARBOHYDRATE DERIVATIVES: N-ACETYLGLUCOSAMINE (NAG) N-ACETYLMURAMIC ACID (NAM) - FOUND NOWHER ELSE IN NATURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

B(1,4)

FOUR AMINO ACIDS MAKE UP WHAT IS CALLED A TETRAPEPTIDE, ATTACHED TO THE NAM.

MOST GRAM POSITIVES COCCI HAVE SIMILAR TETRAPEPTIDE EXCEPT DAP IS REPLACED BY L-LYSINE TETRAPEPTIDE MAY BE FURTHER MODIFIED IN OTHER BACTERIA

PROCARYOTIC CELL ORGANIZATION & STRUCTURE MAJOR STRENGTH OF CELL WALL COMES FROM PERIODIC CROSS LINKINGBETWEEN THE THIRD & FOURTH AA ON ADJACENT TETRAPEPTIDE CROSS-LINKING MAY BE EITHER DIRECTLY (AS IN MOST GM NEGATIVE CELLS) OR VIA A PENTA-GLYCINE LINK (AS IN MANY GM POSITIVE CELLS)

PROCARYOTIC CELL ORGANIZATION & STRUCTURE CROSS-LINKING MAY BE EITHER DIRECTLY (AS IN MOST GM NEGATIVE CELLS) OR VIA A PENTA-GLYCINE LINK (AS IN MANY GM POSITIVE CELLS) NOT ALL PROKARYOTES HAVE PEPTIDO- GLYCAN IN THEIR CELL WALLS: ARCHAEA INSTEAD HAVE CELL WALLS COMPOSED OF POLYSACCHARIDES, GLYCOPROTEINS & PROTEINS. THEY DO NOT HAVE NAM IN THEIR WALLS;

MYCOPLASMA,

WITH NO CELL WALLS, HAVE CELL MEMBRANES WITH STEROLS TO PROVIDE STRENGTH

PROCARYOTIC CELL ORGANIZATION & STRUCTURE IN GM POSITIVES PEPTIDOGLYCAN MAY BE AS MUCH AS 40 LAYERS THICK MOST OF THE CELL WALL (90%) MAY BE MADE UP OF PEPTIDOGLYCAN, BUT THE REMAINDER MAY BE OF ACIDIC POLYSACCHARIDE CALLED TEICHOIC ACID (THEY ARE NEGATIVELY CHARGED MOLECULES)

PROCARYOTIC CELL ORGANIZATION & STRUCTURE GM NEGATIVES HAVE THINNER CELL WALLS (A FEW LAYERS THICK AND APROX. 5 20% OF ENVELOPE). INSTEAD THEY HAVE AN OUTER MEMBRANE STRUCTURE SIMILAR TO THE CELL MEMBRANE, BUT THE COMPOSITION IS SLIGHTLY DIFFERENT: LIPOPOLYSACCHARIDE (LPS) MAKE UP ABOUT 40% OF THE OUTER LIPID BI-LAYER.

PROCARYOTIC CELL ORGANIZATION & STRUCTURE O-SIDE CHAIN CORE POLYSACCHARIDE LIPID A O SIDE: CHAIN VARIES DEPENDING ON THE BACTERIUM CORE POLYSACCHARIDE: RELATIVELY CONSTANT COMPOSITION LIPID A COMPOSED: OF GLYCOLIPIDS ASSOCIATED WITH TOXIC ACTIVITY IN GRAM NEGATIVE BCTERIUM

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE CELL WALL OF THE ACID-FAST BACTERIA MYCOBACTERIA THICK WALL LIKE THAT OF GM POSIIVES.

PEPTIDOGLYCAN IS LESS & ABOUT 60% LIPID.

THE LIPID MAKES THE BACTERIA IMPERMEABLE TO MOST STAINS AND PROTECTS IT FROM ACIDS AND ALKALIS CARBOLFUCHSIN BINDS CYTOPLASM & RESIST ACID ALCOHOL DESTAINING. SLOW GROWTH OF BACTERIA DUE TO INEFFICIENT ENTRY OF NUTRIENTS INTO THE CELL; LARGE AMOUNTS OF ENERGY MUST BE EXPENDED TO TAKE UP NUTRIENTS.

PROCARYOTIC CELL ORGANIZATION & STRUCTURE THE IMPORTANCE OF CELL ENVELOPES IN PRESERVING THE STRUCTURAL INTEGTITY OF BACTERIA IS ILLUSTRATED THROUGH THE LABORATORY CONSTRUCTS PROTOPLASTS & SPHEROPLAST (CELLS WITHOUT MUREIN).

PROTOPLAST= GRAM POSITIVE CELLS WITHOUT MUREIN SPHEROPLAST= GRAMNEGATIVE CELLS WITHOUT MUREIN (RETAIN OUTER MEMBRANE) LYSOZYME OR PENICILLIN USED TO CREATE THESE CELLS. THEY SURVIVE ONLY IN ISOTONIC SOLUTIONS

PROCARYOTIC CELL ORGANIZATION & STRUCTURE THE CELL WALL OF THE ARCHAEA THE PROCARYOTES SURVIVE IN EXTREME ENVIRONMENTS (HIGH SALT, TEMPERATURES, AND pH EXTREMES) CONSIST OF BOTH GRAM POSITIVE AND GRAM NEGATIVE CELLS THEY DO NOT HAVE MURAMIC ACID OR D-AMINO ACIDS. - SOME ARCHAE HAVE A MOLECULE CALLED PSEUDOPEPTIDOGLYCAN (REPEATING UNITS OF NAG AND N ACETYLTALOSAMINURONIC ACID AND L-AMINO ACIDS (NOT THE D-AMINOACIDS FOUND IN TRADITIONAL PEPTIDOGLYCAN).

OTHERS HAVE SURFACE MONOLAYER OF PROTEINS OR GLYCOPROTEINS & LACK PSEUDOMUREIN.

OTHERS HAVE NO WALLS; CYTOPLASMIC MEMBRANE IS THE ONLY CONSTITUENT OF THE ENVELOPE -BETWEEN THE ALTERNATING CARBOHYDRATES IS BETA(1,3) [NOT BETA(1,4) OF PEPTIDOGLYCAN] AND IT IS RESISTAN TO LYSOZYME.

PROCARYOTIC CELL ORGANIZATION & STRUCTURE PERIPLASMIC SPACE: GAP BETWEEN PLASMA MEMBRANE AND THE CELL WALL.

MOST EASILY OBSERVED IN GM-NEGATIVES. LESS DEFINED IN GM POSITIVES ACTIVE AREA OF CELL METABOLISM WITH HYDROLYTIC ENZYMES, TRANSPORT PROTEINS; AND CELL WALL BUILDING BLOCKS.

NOTE DIFFERENCES IN THE SIZE OF THE PERIPLASMIC SPACE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE GLYCOCALYX: REFERS TO ALL POLYSACCHARIDE-CONTAINING SUBSTANCES FOUND OUTSIDE THE CELL WALL (I.E.,

CAPSULE

OR

SLIME LAYER OR GLYCOCALYX

) THE CAPSULE: EXTERNAL TO THE ENVELOPE & PRESENT IN SOME BACTERIA (NOT ALL MEMBERS OF A SPECIES MAY HAVE CAPSULES) A LOOSE GEL, COMPOSED OF POLYSACCHARIDE, PROTEIN, OR ONLY GLYCOPROTEINS PROTECTS CELL FROM DESSICATION, NUTRIENT LOSS AND PHAGOCYTOSIS MAY BE VISUALIZED BY QUELLUNG RXN (SPECIFIC ANTIBODIES BIND TO CAPSULE & INCREASE REFRACTIVITY & CAPSULE APPEARS SWOLEN) SLIME LAYER (GLYCOCALYX): THINNER THAN CAPSULE, AND WHEN PRESENT PREVENTS CELLS FROM DRYING OUT & TRAPS NUTRIENT. POLYSACCHARIDE ARRANGESD AS FIBROUS MATRIX ALSO ALLOWS BACTERIA TO ADHERE TO EACH OTHER AND OTHER OBJECTS (EG., BACTERIA IN DENTAL PLAQUE ON TOOTH SURFACE)

PROCARYOTIC CELL ORGANIZATION & STRUCTURE

PROCARYOTIC CELL ORGANIZATION & STRUCTURE OTHER EXTERNAL STRUCTURES: FLAGELLA RESPONSIBLE FOR MOTILITY USED IN CHEMOTAXIS (MOVEMENT TO OR AWAY FROM SUBSTANCES IN THEIR ENVIRONMENT) OR PHOTOTAXIS MAY BE ARRANGED DIFFERENTLY DEPENDING ON SPECIES SINGLE FLAGELLUM = MONOTRICHOUS ONE FLAGELLUM AT EACH POLE = AMPHITRICHOUS TWO OR MORE FLAGELLA AT ONE OR BOTH POLES = LOPHOTRICHOUS FLAGELLA ALL OVER THE SURFACE = PERITRICHOUS AMPHITRICHOUS MONOTRICHOUS LOPHOTRICHOUS PERITRICHOUS

PROCARYOTIC CELL ORGANIZATION & STRUCTURE FIMBRIA & PILI ( SOMETIMES USED INTERCHANGBLY) FIMBRIA SHORTER AND STRAIGHTER THAN FLAGELLUM - FIMRAE MAY BE EVENLY DISTRIBUTED OVER ENTIRE SURFACE USED FOR ATTACHMENT (EG.,

NEISSERIA GONORRHOEA

USE THEM TO ATTACH TO MUCOU MEMBRANES AND CAUSE DISEASE) PILI - USUALLY LONGER THAN FIMBRIAE; NUMBER ONLY 1 OR 2/CELL - USUALLY USED IN DNA TRANSFER DURING CONJUGATION