Lecture 2/Chp 3,4 Flashcards
What are some unusual prokaryotes?
Star-shaped
Rectangular
What are some bacterial arrangements?
Pairs
Diplococci or diploma ills
Clusters
Staphylococci
Chains
Streptococci
Streptobacilli
Name the common bacterial structures?
Plasma membrane Gas vacuole Ribosomes Inclusions Nucleoid Periplasmic space Cell wall Capsules and slime layers Fimbriae and slime layers Flagella Endospores
Gas vacuole function?
Inclusion providing bouyancy
Cell wall functions?
Protection from osmotic stress, helps maintain cell shape
Capsules and slime layer functions?
Resistance to phag and adherence to surfaces
Film rise and pili functions?
Attachment to surfaces Conjugation Transformation Twitching Gliding
Flagella functions?
Swimming
Swarming
Endospore functions?
Survival under harsh environmental conditions
What are the components of the Bacterial Cell Envelope?
Plasma membrane
Cell Wall
Layered outside cell wall
Explain the differences in cell membranes of bacterial and eukaryotic cells.
Bacteria do not contain cholesterol
Bacteria have hopaniods
1. Cholesterol like
Infoldings are present
How is the chemical relationship different in Bacteria/Eukaryotic lipids vs Archaea?
Bacteria and Eukaryotic lipids in the cell membrane have ester bonds= ROOC
Archaea have ether bonds
ROR
1. Bilayer is C20= diethers
2. Monolayer is C40= tetraethers
Inclusions functions?
Granules of organic or inorganic material storage for future use.
What some examples of inclusions?
Metabolic nutrients Glycogen Carbon Phospage= Volutin Amino Acids= cyanophycin Sulfur Iron=Magnetosomes 1. Cytoskeletal protein Mamk for chains
Gas vacuoles
Microcompartments examples?
Carboxysomes
1. CO2 fixing bacteria
2. Fibulae-1-5-bisphosphate carboxylate
(Rubisco)
What are the 3 eukaryotic cytoskeletal homologous in bacteria?
FtsZ=microtubule
Cell Divison
MreB=microfliament
Cell shape, my be involved in chromosome segregation
CreS=Intermediate filament
Induces curvature in curved rods
What are the 3 parts to Bacteria flagella?
Filament
Hook
Basal Body
How do Flagella help bacteria move?
For liquid movement it is a helicopter.
For viscous movement
It is spirochete
Solid surfaces
Twitching
Gliding
What are spores resistance to?
Heat
Radiation
Chemicals
Desiccation
What protein makes spores resistant?
Keratin
What are the basic shapes of microbes?
Bacillus= rods Coccus= spherical Spiral 1. Spirillum= one or more twists 2. Vibrio= curved rod 3. Spirochete=flexible, helical spirals
Why is large surface/volume ratio good?
The uptake of nutrients and the diffusion of becomes more efficient.
Lead to rapid growth rate.
What is anaerobic ammonia oxidation?
Nitrogen fixation
What ribosome units do bacteria and archer a have?
70S
30 and 50
Small subunit 30=16S
Large subunit 50=23S and 5S
How does DNA condense in bacteria?
Supercoiling because of a lack of histones.
What are some properties of Plasmids?
Extra chromosomal DNA
- Bacteria
- Archaea
- Fungi
Closed circular
Replicates independently
1. Episodes may integrate into chromosome
2. Inherited during cell division
Confer advantage to host
What are the types of plasmids?
Conjugative= transfer DNA
R Plasmids= resistance
Col. Plasmids=produce bacteriocins destroy’s related species
Virulence Plasmids= Virulence
Metabolic Plasmids=Carry genes for enzymes
Bacterial Cell Wall’s are made of what and how?
Peptidoglycan=Murien
Two alternating sugars
- N-acetylglucosamine (NAG)
- N-acetylmuramic acid (NAM)
Alternating D/L amino acids
Strands are crossed linked
Helical shape
What else to Gram-Positive Cell Wall have?
Trichroic acids Negatively charge 1. Maintain cell envelope 2. Protection 3. Bind host
Explain what exoenzymes are?
Gram-positive bacterial proteins aid in degradation of large nutrients
Why are Gram-Negative Cell Walls more complex?
Have a thin layer of peptidoglycan surrounded by an outer membrane
Have LPS
No trichroic acids
Braun’s LPS connect outer membrane to pep
LPS components?
Lipid A= Endotoxins
Core polysaccharide
O side chain= O antigen
Contributes to neg charge
Contribute to biofilm
Protection via O antigen
Why is the Gram Neg Outer Membrane more permeable?
Porin proteins and transporters
What is Plasmolysis?
Cell wall and Plasma membrane come apart in a hypertonic environment
Instead of peptidoglycan what do Archaeal cell walls have?
Pseudopeptidoglycan
What are the outermost components of the cell wall?
Glycocalyx
- Capsules and slime layers
- S. Layers
What is special about S layers?
Potential use in nanotechnology
They spontaneously associate
What sex pili required for?
Conjugation
What function does Fimbriae have?
Twitching motility or gliding motility
What function does Flagella have?
Motility
Swarming
Attachment
Virulence
What are the parts of a Flagella?
Filament= cell surface to tip
Hook= links filament to basal body
Basal Body= series of rings that drive flagellar motor
Explain bacterial flagellar movement patterns?
Counterclockwise causes forward motion
Clockwise causes a stop and tumble
What is the flagellar movement mechanism?
EMF of proton [H] gradient concentration through the MotB MotA protein channel.
List some components of the Endospore structure?
Surrounded by exosporium
Thick protein layers form spore coat
Cortex beneath of thick pep
Core has nucleotide/ribosomes
What makes an Endospore resistant?
Calcium w/dipicolinic acid
Small, acid soluble, DNA-binding proteins (SASPs)
Dehydrated core
Spore coat and Exopsorium
DNA repair enzymes
