Topic 2 Bacteria Flashcards
How many shapes can bacteria take and what are they ?
They can take 5 shapes ;
Spherical
Rod
Comma
Spiral
Pleomorphic
What is the singular and plural name for spherical bacteria and what are two examples?
Singular coccus plural cocci
Staphylococcus aureus and Streptococcus pyrogenes
Why are spherical bacteria denoted as default?
They are noted as default for bacteria as bacterias without any extra genomes for their cytoskeleton will by “default” be this shape
What is the singular and plural name for rod-shaped bacteria and what are two key factors?
The rods have advantages compared to others
They are very common
The singular is bacillus and plural is bacili
What is the plural and singular name for comma shaped bacteria and what is one cool feature that have?
The singular vibrio and plural vibrios and they can flex
What is the plural and singular name for spiral shaped bacteria and what is a key factor about them?
Sprillum s. sprilla pl.
They can swim (cork screw back & forth) through viscous or tuberlent fluids
What is the name for uncategorized an varied shaped bacteria
Pleomorphic
How do bacteria cells take shape ?
Its determined by the organization of the cell walls
Radius is key for surface to volume ratio
What is morphology dependent
Nutrient uptake efficiency ( surface - volume ratio)
What type of motility can filaments have ?
They can have a gliding motility
How many complex multicellular bacteria arrangements are there?
There 3
Hypae
Mycelia
Trichomes
What are tri chomes and what are they coated in
Trichomes are long unbranched chains of cells coated in a polysaccharide sheath
What are hypae ?
Long branching filaments of cells
What bacteria is a common trichome
Cyanobacteria
What is mycelia?
Three dimensional networks or clumps of hypae
What do trichomes and hypae both have in ommon
They have channels for intracellular passages of materials like nutrients and signalling molecules
What size can prokaryotes range from?
0.2 micrometers - >700 micrometers in length/diameter
What size range are bacteria cells?
0.5 micrometers -5 micrometers in length/ diameter
What is the size range for rod shaped bacteria cells?
0.5 micrometers- 4 micrometers , 1-15 micrometers long
Why do bacteria need a minimum size ?
Bacteria and other cells need a minimum cells to be able to fit genome proteins and ribosomes without cells cant live
What are 2 big exceptional bacterial cells ?
Euplopiscion fish …. and thiomargerita
What size range is euploiscion fishelosoni and where are they found?
200-700 x80 micro meters and they can in the gut of surgeon fish
What is the size of thiomargerita ?
Up to 700 micrometers in diameter / length
What is the bacteria shape or thiomargerita &epulop
Thio is spherical and epulop is cigar (rod)
What are 3 advantages to being small bacteria cell ?
Higher surface to volume ratio
Better metabolism and growth rate and faster evolution
Greater rate of nutrient/waste exchange per unit volume
Why is having a higher surface to volume ration good?
Its good because the volume is disproportional surface; so as the volume is getting theres not enough surface to keep up with all the stuff inside the cell at the same rate as small therefore the cell need to work more to transport
Does being big or small have an advantage ?
None has an advantage as both have pros and cons
Where can you find very small cells of 0.2 -0.4 micro meter ?
You can find them in open marine environment
What 11 organelles and molecules make up the bacterial cytoplasm?
DNA nucleoid
Chromosomes packed proteins
Enzymes involved in synthesis of DNA , RNA
Regulatory factors
Ribosomes
Plasmid(s)
Enzymes that break down substrates
Inclusion bodies
Gas vesicles
Magnetosomes
Cytoskeleton structure
What is DNA nucleoid composed of and what the function?
Composed of DNA ,RNA and PROTEINS
Function of storing genetic info and gene expression
What is chromosomes packed protiens composed of and what the function?
Proteins
Protecting and compacting genomic DNA
What is ‘enzymes involved with synthesis of DNA and RNA ‘composed of and what the function?
Proteins
Function of replication of genome and transcription
What is regulatory factors composed of and what the function?
RNA proteins
Function of controlling replication ,transcription and translation
What is ribosmes composed of and what the function?
Proteins & RNA
Function is translation (protein synthesis)
What is plasmid composed of and what the function?
DNA
function is variable , encoding non chromosomal genes for a variety of functions
What is enzymes that break down substrates composed of and what the function?
Proteins
Energy production and proving anabolic precursors
What is inclusion bodies composed of and what the function?
Various polymers
Store carbon , phosphate, nitrogen,sulfate
What is gas vesicles composed of and what the function?
Proteins
Buoyancy
What is magnetosomes composed of and what the function?
Iron, protein and lipids
Help orient cell during movement
What is cytoskeleton structure composed of and what the function?
Proteins
Cell wall synthesis ,cell division and parting chromosomes during replication
Magnotsomes are only found in bacteria
What type of bacterial shape and size (big or small) do you want to be in the ocean with not that much nutrients ?
In the ocean you would want to be a rod with a higher surface - volume ratio to make sure you able to have any chance to get the most nutrients you. Can
What shape and size (big or small ) do you want to be when you have alot of nutrients near you ?
You would want to be spherical and big as you need to be able to store the nutrients
What are plasmid(s) and what is a negative thing about them?
They are small segments of DNA that dont have genes that code for ribosomes or things that are essential for living
What is the biggest region in a bacterial cell and what does it contains and what does it lack ?
The biggest region is the DNA nucleiod it contains chromosomes and DNA replication & Machinery
What is the cytoplasm ?
It is an aqueous environment within the plasma membranes that contains various components
How is DNA packed in the cell?
As sugar phosphate (PO4-) backbones that are holding the two DNA strands together are negatively charged the cations of Mg2+ ( magnesium) , K+ (POTASSIUM) or Na+ (SODIUM) neutralize the charges and then small positively charged proteins bind to the DNA chromosome to help maintain the condensed structure and finally the enzyme topoisomerases supercoils the DNA
What is different about histones in bacterial cells?
There histones dont wrap around DNA
What is the sulfur globule and it function and what cell tends to have them ?
Storage for sulfur and can use sulfur for energy , thiomargerita and thiomargerita manifica
What is polyhydroxybutyrare (PHB) and what can they substitute?
It is a lipid polymer that stores carbon and can substitute from plastic
What do gas vesicles do ?
Its provides buoyancy ; it regulates the cell position in water in response to nutrients or light
What are carboxysomes and what bacterica can they be found in ?
They are a container for RUBISCO which fixes carbon into bio mass
What are magnetosomes function and what surronds them ? Are they in all bacterial cells?
They help the cell with direction finding and a lipid membrane around they are oriented in a chain , no magnetosomes are not all in bacterial cells
What are 3 reason why the bacterial cytoskeleton is important
Helps with cell division
Keeps everything in right place
Series of internal proteijs
What 2 cytoskeleton proteins are key for cell wall sythesis during cell division
MreB
Ftsz
What is MreB composed of and why is it key
Its is composed of homologous of actin -microfilament its helps guide cell wall formation that help rods get it shape
What is FtsZ and and why is it important
FtsZ is homologs of tubulin that help guide cell division its form a ring called z rings which is key for bacterial division
What is ParM made up and whats its function?
It forms actin like filaments and using ATP they help move and split plasmid to opposite sides for cell division aka partitions proteins
What 4 things are the cell envolope made out of?
Cell wall
Inner (cytoplasmic memebrane)
Outer membrane
Plasma membrane
What are the 3 main roles of the plasma membrane?
Being able to control the access of material to the cytoplasm through different permeability (permable barrier)
Sensory system - proteins can detect environment and alter gene expression in response
Capturing energy for respiration and photosynthesis which allow motion for flagella and transport chains that create PMF (protein motive force
What is the plasma membrane and what does it have and consist of ?
The plasma membrane is a phospholipids bi layer embedded with proteins which has a hydrophobic cord and hydrophilic ends interscting with the cytoplasm or external environment
Can bacterial cells have a second outer membrane which is part of the cellular envolope ?
Yes
How does the plasma membrane assemble itself?
As the fatty acid tails love each other they join each other and the polar heads repel
In a bacterial phosphoplid what connected the fatty acid to the polaf head
Its is linked by ester linkages
What does a double bond in a
Fatty acid do ?
They give a kink and become unsaturated and more fluid
What does single bond carbon in a fatty acid do
Its just straight and make its saturated which is less fluid
What are hoponoids and are they in every bacterial cell.
Hoponoids are in some bacterial cells and they help the stability of the membrane
What molecules can easily cross the membrans
Small uncharged molecules like O2 & CO2
How does water cross the membranes
Through aquorin protein channels (osmosis)
What is osmosis?
Spontaneous net movement or diffussion of molecules through a membrane from region of high to low water to equalize it
What are the two types of active transports ?
Co transport and ABC transport
What are the two types of co transporteds
Symport & antiport
What is facillited difusions and does it require ATP?
Its proteins channels that help move molecules along with the concentration gradient and its not require ATP
What is symport co transport
It moves both and favourable and unfavourable molecules the same way using atp
What is antiport co transport
Using atp it moves unfavourable and favourable protein in opposite directions
What is ABC transport ?
Atp binding cassetes that move particles against concentration gradient using ATP
The nutrients binds to a solute biding protein and the complex interacts with the cell which start atp hydrolysis that changes the shape and allows the nutrient in
What is protein secretions ?
Its a pathway for proteins to get out outside to the cytoplasm using atp secretory proteins move the protein outsdie the cell where the proteins later fold
What are three key things about the cell wall ?
They protect the cell from osomotic lysis
Give bacteria cells shape
Compoaws of Matrix of crosslinked peptidoglycan
What is peptidogylcan composed of and linked by ?
NAG and NAM which are linked by beta 1,4 glycosis bonds (peptide cross link)
What is NAG stand for
N-acetylglycosamune acid
What does NAM stand for
N-acetylmumaric acid
Is nam linked to nam?
Yes
What type of amino acid is in a gram negative cell ?
DAP (diamino acid pimelic acid )
What cross bridge doesn a gram negative cell have ?
Peptide cross link
What type of link does the nam to nam have in gram positive cells ?
Pentagylcine interbridge (5 gylcines
Where does the production of the cell wall happen?
Cytoplasm
D- VS I- amino acids
D - are sterioisomers ( mirror images) or I
How does the cell wall form?
- A single nam with 5 amino acids (pentapeptide precusser) which is connected to UDP is made in cytoplasm
- The lipid bactprenol attached to NAM and then NAG connects to NAM
- The lipid flips the attached structure onto the periplasm past the plasma membrane
- Transglycosylation connects glycan chain with beta 1,4 gylcos linkages
- Transpeptidation (FtsI enzyme which catalyzes ) connects peptide chain getting rid of one amino acid (from 5-to-4)
- Divisome associated with FtsZ ; division enzyme that makes cell scaffold
What 3 things can degrade the cell wall ?
Lysozyme and lysostaphin and beta lactam antibiotics
What does lysozymes do ?
Lysozymes cute the backbone of peptidogylcan which destroys the cells shape possibl cause lysis hypotonic conditions where cell just burst
What does lysostpahin do to the cell wall?
Lysostaphin acts on the cross bridge
What is key in the beta lactam anti biotics structure ?
Its beta lactam ring
What does beta lactam antibiotics prevent and inhibits
Its prevents peptidoglycan cross linking and inhibits the FtsI enzyme transpeptidation.
What is beta lactamase ?
Its an antibiotic resistance that destroys the key beta lactam ring structure which allow cell wall scaffold to continues
What are 3 key things for gram postivie cells ?
Very thick layer of cell wall
Narrow periplasm space
Long negatively charged sugar technoic acid embedded in peptidoglycan
What are three key things about gram negative cells?
They have a very thin layer of peptidogylcan
Outmembrans is composed of lipid poly sccarchides ( lipids are down in membrane with long polysacchrides chain sticking out of lipid
Periplasm have a varying width
How does gram postive move nutrients through matrix
They dont need any extra help as they have large pores
How does gram negative move nutrients past there membrane
Using either porin trimers which three proteins that does use ATP for small then to active transport or Ton b dependent which is connected via battery in the cytoplasm powered by pmf exb exd
How many pmemebrans do gram negative and gram postive hsve
Negative 2 positive 1
What is gram negatives type 3 secretion and what is it usualy secreting
Is a single step protein channel which extends throughout the whole cell envolope reaching to a neighbouring organelle cytoplasm and its usually secreting pathogens
What is motility?
Propelling flagella in prokaryotes
What are autotransporters
Moving from periplasm to outside directly
What are the 3 pieces flagella is composed of
Basal Body
Hook
Filament
How long is the flagella filament ?
5-10 micro meteres long
What is the flagella filament made up of
Flagellin protein
What is the hook made up of and whats its function and where does it connect
So it connects to the basal body its made up of proteins and allow flagella to propel
What is the basal body , where is it located amd anchored to and what does of do
The basal body anchors the the flagella to outer membrane cell wall and cytoplasmic membrane and its embedded im the plasma membrane and turn the filament like a proppeller with pmf
What are 3 characteristics about flagella
Rigid filmament
Spiral
Hollow
Do all flagella rotate in the same direction
Yes
What motion does spinning flagella create
Runs and tumbles bc filaments get tangled
Do bacteria have steering
No
What do chemeotaxis do to flagella ?
Is basically using chemical signals from the environment to direct flagella movement along gradients
What are the other taxis
Phototaxi. Light
Aerotaxi oxygen
Osmotic taxi - osmotic strength
Is flagella a secretoy system ?
Yes
Can cella have internal flagella ?
Yes
What is gliding motiity and what cell tends to have this
Smoothly sliding over surfaces , cyano amd myco bacteria
What is twitching motility?
Its a slow process using pilli that extend and pull across a surface
How can actin propel bacteria
Polymerization of actin propels the bacteria like shigella to the adjacent cell
What are adherence molecules and whar 4 bacteria make up them
There are lazy cells who let food come to them by letting cells stick to them on the surface
Pili
Capsules
Stalk
S-layer
What are pili ?
Fibers of pilin protein that can attach to a host cell and “posses” them
What is stalk and what type of gram cell has them and what does it contain and a benefit
A skinny tublar (rod) extension through the entire cell envelope with tipped adhesion called hold fast by polysaccharides
contaims cytoplasm
Only found in gram negative
They have a tiny volume and a big surface area for maximum nutrient absorption
What does fimbraie do ?
Helps cell attach to surfaces
What are capsules and what grams are they found in ?
They are a think layer a sugar (polysaccharide) which can sheild bacteria like pathogens. Capsules makd bio films.
Found gram negative and gram postive
What are capsules protective against?
Host imminity
Against decessition
Harsh environments
What are s layer and what are they made from and what grams are they found in?
The are a protection layer outside of the cell they are made from crystalline array of interlocking proteins they are found in gram postive & gram negative
What 2 things do s layer protect against
Bacteriaphogoges
Predation
Techoic acid
A poly saccharide
