Microbial Diversity

Cell

it is the basic structural and functional unit of living organisms

cell theory

it is a collection of ideas and conclusions from many different scientists over time that describes cells and how cells operate

Robert Hooke 1665

who discovered cells and when?

anton van leeuwenhoek 1674

who observed living cell and when?

robert brown 1883

who discovered nucleus and when?

felix dujardin 1835

who discovered fluid content of cell and when?

Matthias Schleiden 1838

who proposed all plants are made up of cells and when?

J.E. Purkinje 1839

who named fluid content of cell as protoplasm and when?

Theodor Schwann 1839

who proposed all animals are made up of cells and when?

Carl Heinrich Braun 1845

who proposed cell is the basic unit of life and when?

Rudolf Virchow 1855

who proposed all cells arise from pre-existing cells and when?

prokaryotes

it includes bacteria and archaea

Cocci

usually round but can be oval, elongated or flattened on one side. When it divides to produce, the cells can remain attached to one another.

diplococci

remain in pairs after dividing

streptococci

divide and remain attached in chainlike patterns

tetrads

divide in 2 planes and remain in groups of 4

sarcinae

divide in 3 planes and remain attached in cube-like groups of 8

staphylococci

divide in multiple planes and form grapelike clusters or broad sheets

bacilli

they mostly appear as single rods

diplobacilli

appear in pairs after division

streptobacilli

occur in chains

coccobailli

looks oval

vibrios

bacteria that look like curved rods

spirilla

- have a helical shape, like a corkscrew
- Has whip-like external appendages called flagella for movemen

spirochetes

- spirals which are helical and flexible
- Move by means of axial filaments that looks like flagella

flagella

Has whip-like external appendages in spirilla for movement

axial filaments

move by means ______________ that looks like flagella

Coccus

Single coccus

diplococcus

pair of two cocci

tetrad

grouping of four cells arranged in a square

streptococcus

chain of cocci

staphylococcus

cluster of cocci

bacillus

single rod

streptobacillus

chain of rods

Glycocalyx

- means sugar coat
- term used for substances that surrounds cell

capsule and slime layer

what are the two types of glycocalyx?

capsule

- substance is organized and firmly attached to the cell wall
- it protects pathogenic bacteria from phagocytosis by the cells of the host

slime layer

- the substance is unorganized and loosely attached to the cell wall
- it enables pathogenic

flagella

are long filamentous appendages that propel bacteria

1. monotrichous
2. amphitricous
3. lophotrichous
4. peritrichous

what is the arrangement of flagella?

monotrichous

single polar flagellum

amphitricous

a tuft of flagella at each end of the cell

lophotrichous

2 or more flagella at 1 pole of the cell

peritrichous

flagella distributed over the entire cell

filament

long outermost and constant in diameter

hook

where filament is located and consist of different protein

basal body

it anchors the flagellum to the cell wall and plasma membrane

taxis

it is the movement of bacteria toward or away from a particular stimulus

axial filaments

allows spirochetes to move in a spiral, helical, or inchworm manner

fimbriae and pili

they have hairlike structures, most often observed on gram-negative bacteria

Fimbriae

can occur at the poles of the bacterial cell or they can be evenly distributed over the entire surface of the cell

Pili

usually longer than fimbriae and only one or 2 every cell

Cell Wall