Biology Of Microorganisms 25%

Front 1

Bacteria
Gross Morphology

Back 1

cell size
Smallest living 0.25umto0.25um 0.45to 2.0
0.15-mycoplasmas
0.25-chlamydiae
0.45-rickettsiae
2.0-many bacteria

Front 2

Shapes of bacteria (prokaryotes)f

Back 2

Spherical Shapes (cocci or coccus)
Bacillior Bacillus(rodlike)
Vibrio (comma shape)
Spirochette (wavy)
Spirillum-(corkscrew0
Pleomorphic (variety of shapes & sizes
diploccus-pair of cocci
streptoccus-chain of cocci
tetracoccus-four cocci arranged in a cube
streptobacilli-form long chains

Front 3

Structures external to cell wall

Back 3

the glycocalyx (capsule, slime layer, or extracellular polysaccharide) is a gelatinous polysaccharide and or polypeptide covering.
Capsules may protect pathogens from phagocytosis.
Capsules enable adherence to surfaces, prevent desiccation, and may provide nutrients

Front 4

flagella-

Back 4

relatively long filamentous appendages consisting of a filament, hook and basal body
Flagella rotate to push the cell.
Motile bacteria exhibit taxis: positive taxis is movement toward an attractant & negative taxis is movement away from a repellent.
Flagellar (H) protein functions as an antigen.

Front 5

Axial Filaments

Back 5

Spiral Cells that move by means of an axial filament, called spirochetes.
Axial filaments are similar to flagella, except that they wrap around the cell.

Front 6

Fimbriae and Pili

Back 6

Fimbriae and pili are short, thin, appendages.
Fimbriae help cells adhere to surfaces.
Pili join cells for the transfer of DNA from one cell to another.

Front 7

Cell Wall

Back 7

Gram negative thin surrounding layer called outer membrane. Lipopolysaccharides ada endotoxins part of outer membrane. A space periplasmic space separates cell wall from outer membrane and contains subtance called periplasm.

Front 8

Cell Wall and Cell Membrane

Back 8

Gives shape to organism and prevents bursting. All bacteria have semirigid cell wall with mycoplasma.

Front 9

Component of Cell Wall

Back 9

Peptidoglygen.
Teichoic Acid associated with peptidoglycen in gram positive bacteria.

Front 10

Cell Membrane

Back 10

All prokaryots have cytoplasm surrounded by a cell memebrane Aka plasma membrane.
Cell membrane conforms to the fluid mosaic model means proteins float with in a double layer of phospholipids.
Respiratory enzymes are located at the cell membrane and the membrane assists DNA replication and has attachment points for bacterial flagella.

Front 11

Cytoplasm

Back 11

Is the fluid component inside the plasma membrane. The cytoplasm is mostly water, with inorganic and organic molecules, DNA, ribosomes and inclusions.

Front 12

Nuclear Area

Back 12

The nuclear area contains the DNA of the bacterial chromosome.
Bacteria can also contain plasmids, which are extrachromosomal DNA circles.

Front 13

Ribosomes

Back 13

Contain proteins and RNA and are locations where protein is synthesized.
The cytoplasm of a procaryote contains numerous 70S ribosomes, ribosomes consist of rRNA and protein.

Front 14

Inclusions

Back 14

Reserve deposits within chytoplas of procaryotic cells.
Can also accumulate certain nutrients when they are plentiful and use them when environmentis deficient.

Front 15

Spores or Endospores

Back 15

Highly resistant internal structures spores are formed during normal lifecycle when environment becomes to harsh.
Sporeformers include the agents of anthrax, tetanus, botulish , gas gangrene.
Spores contain dipicolinic acid and calcium ions.