Chapter 2 Flashcards
Cocci
Round shape
Bacilli
Rod shape
Spirochets
FLEXIBLE Cork screw shape rods
Spirilla
Rigid spiral shape usually shorter than spirochetes
Pleomorphic
No consistent shape
Stalk
Anchor bacteria to surfaces
vibrios
comma-shaped (subset of spirilla)
bacterial cell envelope
the material that encases the entire bacterial cell. Can be the membrane, cell wall, and any layers outside the cell wall (capsul or slime layer)
plasma membrane
the inner most layer. It has 2 parts. lipid part and the protien part.
bacterial cell wall
helps maintain the bacteria’s shape. there are gram-neg and gram-pos. the outer wall in gram-neg is mostly made up liposaccharides that contributes to surafce charge, membrane stability, and permeability. The periplasmic space is in the middle and is involved in peptidoglycan synthesis and detoxification
who developed stain
christain gram
how does penicillan effect the bacteria cell
penicillan targets the enzyme, transpeptidase to weaken the walls. which hold together the peptidoglycan wall. Thus, the cell lyses.
Most outer layer in envelope for gram-neg or pos
capsules
- not easily washed off
-made of polysaccharides
-can be seen with a thick stain and light-micro
-prevents drying out and can deter viruses
slime-layer
- easily washed off
-made of polysaccharides
-more difficult to see under light-micro
S-layer
-protects against pH
-made of protein of glycoprotein
-in gram-neg, adheres non-covaletly to outer membrane
-in gram-pos, it is associated with the peptidoglycan layer
bacterial cytoskeleton
made of protien filaments that maintain shape and intracellualr components like ribosomes, plasmids and inclusions
Cytoskeleton components: inculsions
inculsions are common in all cells. they are typically used for storage
Cytoskeleton components: ribosomes
for protien synethsis - composed of rRNA and proteins. have 2 sub-units, 30S and 50S
Cytoskeleton components: Nucleoids
typically dsDNA formed in a circle. Baterial chromosomes are much larger that the cell so it must undergo compaction to fit. Chromosomes are located in the nucleoid
Cytoskeleton components: plasmids
dsDNA that exist outside of the nucleoid.
episomes - type of plasmid that are able to integrate into the cell’s chromosome and be replicated with the rest of the chromosome
flagella
in bacterial they grow from the tip
in archea they grow from tip to base
in eukarya they grow from the tip (but requires more complex assebly process)
chemotaxis
chemotaxis is the movement of a cell in a favorable direction
5 methods of movement
- flagella
-smooth swimming (counter cw)
-tumble manuver (cw)
-energy: proton motive force - flagella mediated swarming
-group movement across moist surface
-energy: PMF - corkscrew by spirochetes (not for exam)
- Twitching
-pili extends and pulls cell in
-energy: ATP hydrolysis - Gliding
-smooth moving without any appendages
-energy: PMF
Endospore
dormant cells in bacteria. created when nutrients are low in hopes nutrients will come back
Sporulation cycle
7 steps
- chromosomal replication
- Asymetric cell division
-septum forms off-center creating two unequal cells (larger is mother) - engulfmaent (mother engulfs the forespore leading to 2 membranes)
- cortex formation (peptidoglycan layer forms [cortex] to dehydrate the core)
- Coat formation (80 protein protective coat)
- Maturation (forespore gets further dehydrated, making it highly resistant)
- Release (mother lyses, releasing mature endospore into environment)
differences between pseudomurein wall in achea and peptidoplaycan (murein)
-amino acid in cross links
-sugar components
-glycosidic bonds
these differences make achea more resistant to lysosome, penicillan, and other chemicals that target peptidoglycan
Lifestyle of a virus in prokaryotes
either lytic infection or Lysogenic infection
