Chapter 3: bacterial cell structure Flashcards
how do microorganisms differ from eukaryotes?
-dna is packaged differently (lack of nucleus and histones)
-makeup of the cell wall (peptidoglycan + others)
-internal structures: lack of membrane-bound organelles
what are some organelles and structures that all bacteria have?
-cytoplasmic membrane,
-cytoplasm,
-ribosomes,
-chromosome/s
define pleomorphic?
the ability to change in shape
what shape is a Coccus bacterial cell?
round shape (think pearls)
what shape is a Bacillus bacterial cell?
rod shpaed (think cylinder)
what shape is a Vibrio bacterial cell?
curved rod (think comma)
what shape is a Coccobacillus bacterial cell?
curved rod but short and plump
what are 4 ways to describe bacterial arrangment?
-diplococccus: single divided into pair
-chain: cells divide on one plane
-cluster: cells divded in random planes
-tetrads: cells divide in 2 planes
cubes: cells divide in 3 different planes
how can appendages be characterized?
two groups: provides motility (flagella and axis filament) and those that provide attachment points or channels (fimbriae, pili and nanotube)
2 types of cell wall based on Gram staining?
Gram positive and Gram negative
how do gram positive vs gram negative cell walls differ?
-gram positive: purple stained, thick peptidoglycan protein layer w no outer membrane layer, contains teichoic acids
-gram negative: pink stained, thin peptidoglycan layer surrounded by outer membrane layer
what is a biofilm?
aggregation of microorganisms growing together on a surface or substrate
(colonies on a agar plate)
name a substance in the envelope structure of some bacteria that can cause severe symptoms in humans?
Glycocalyx (also known as a capsule: tightly bound to cell)
-formed by many pathogenic bacteria
what are some layers outside the cell wall?
-slime layer
-S-layer
-outer membrane
all serve as protection
a basic bacterial cytoplasm contains…
cytoskeleton
inclusions (granules of storage)
ribosomes (protein synthesis)
nucleoid (think chromosome)
plasmids (small, nonessential pieces of DNA)
what is an endospore?
dormant, thick walled structures extremely resistant to extreme temps, radiation, chemicals, and prevents desiccation
how many stages in the sporulation creation cycle?
3!
Activation: basic prep
Germination:
Outgrowth:
