Module 7

These flashcards cover key terms and definitions regarding the external structures of prokaryotes and eukaryotes as discussed in the lecture.

Coccus

Circular shaped bacteria that have a surface area to volume ratio that resists drying.

Bacillus

Rod-shaped bacteria that do not resist drying.

What are examples of Coccus and Bacillus

Diplo, tetrad, strepto, straphylo

Spiral

Spherical shaped, high surface area to volume ratio, sensitive to drying

What is an example of spiral?

Vibrio, spiral, spirochete

What is the size of bactetia?

0.2 to 2.0 in diameter and 2 to 8 mm long

Two types of shape and arragngement decided by heredity are?

Monomorphic = single shaped, most bacteria fall into this shape

Plemorphic= many shapes (ex. Cyanobacterium sp.)

Virulence

The degree to which a pathogen causes disease (how sick you get)

Virulence factor

A component of an organism that determines its capacity to cause disease. (helps cause disease)

What is the Glycocalyx?

A coat or layer surrounding the bacterial cell, made of polysaccharides or polypeptides or both

What are the two types of Glycocalyx?

Capsule - firmly attachted to cell wall, is a virulence factor, protects cell from phagocytosis, attachment to tissue, food source, made of sugar substance that helps hide from WB cells

Slime layer - loosley attached, traps nutrients, prevents desiccation (drying)

• both help cells in biofilm attach - extracellular polynueric substances (EPS)

Describe the Eukaryotes Glycocalyx with its make-up, function, an a example

Make-up: carbs covalently bonded (firmly attached) to plasma membrane

Function: strengthen cell, attachment, cell-to-cell recognition

Ex. Fish that are slimy

Prokaryotic Flagella

Long appendages used for propulsion in prokaryotic cells (long hairs that help with movement)

Describe the movement of Prokaryotic Flagella

50 secs= 0.0001 mph = 37 cell lengths/secs

Specific to Prokaryotes: Rotates like a propeller, clockwise or counter clockwise, has series of “runs” and “tumbles" to move

Describe the structure of Prokaryotic Flagella

Filament - flagellin protien and hollow core

Hook - attatchment of the filament to the motor

Basal body - anchor and motor

Describe the position of flagella

Monotrichous= (one) single flagellum

Amphitrichous= (1-few) tuft of flaggella at each pole

Lophotrichous= (a clump) tuft of flagella from ONE pole

Peritrichous= (a group) flagellum over whole surface

Describe the Strains of flagella

H Ag - flagella

O Ag - LPS

K Ag - Capsule

Diffeent serovars- E. Coli O157:H7

Describe the functions of flagella and the two types of stimuli involved

Taxis= movement of bacteria due to stimuli ( attractant or repellent)

Chemotaxis = chemical stimuli

Photoaxis = light stimuli

Receptors much recive the stimuli and lead to movement

Describe Eukaryotic flagella or cilia

Structure: basal body, shaft (microtubules)

Enclosed by plasma membrane

Internal mircotubules in 9+2 arrangement

(microtubules are long,hollow tubes made up of tubulin protien)

Movement: wave like motion

Function: in movement like sperm or cilia in lungs

What is Axial Fllament?

AF = Internal flagella

Spirochetes only

Move through tissue like a drill

Ex. Treponema Pallidum= syphilis

What are Fimbre and Pili?

short hair-like appendages usd for attatchemet or conjugation

Gram negative bacteria only

composed of protien pilin

Shorter/thinner than flagella

Describe Fimbre

Polar position or over whole surface

100 per cell

Function in adherence; Neissereia gonorrhoeae

cannot colonize your genital tract without fimbriae

D. Biofilm

describe pili

Longer than Fimbriae

1 or 2 per cell

twitching motility

function in “sex" - transfer DNA during conjugation

called sex pili

Biofilm

A community of microorganisms living together on a surface, often encased in a protective layer.

Desiccation

The process of drying out.