Cell Structure and Function of Bacteria and Archae
Microbiology 3020 with White at University of Central Florida
About this deck
By: Jaclyn Anderson
Textbook:
Biology Of Microorganisms 11th
Created: 2011-10-15
Size: 158 flashcards
Views: 18
Textbook:
Biology Of Microorganisms 11thCreated: 2011-10-15
Size: 158 flashcards
Views: 18
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What does the spatial arrangement of a cell protect?
biochemical rxns that provide for maintenance and synthesis
What does the membrane of a cell do?
provides boundary, maintains cell integrity
Cells maintain required what? Withoyut this, the cell woul die
energy
How do unicellular organisms reproduce? Which means what?
independently; reproduction of cells = reproduction of organism
Genetic material within cells specifies what?
activites and organization of cell
How do multicellular orgs differentiate?
into specialized structures
Cells must be compartmentalized....why?
need to exchange materials with their environment to physiological needs
Sequestering certain biochemical rxn's within a cell via compartmentalization is important why?
bc it will sequester do different areas where the specialized Rxn's can occur
Compartmentalization can protect essential cell structures, how?
by protecting them from being hydrolized by certain enzymes
Give the following info for a virus: cell structure, DNA and RNA, nucleus, ribosomes, organelleles, multicellular, cell wall
Cell Structure: N/A
DNA and RNA: No
Nucleus: N/A
Ribosomes: N/A
Organelleles: N/A
Multicellular: N/a
Cell Wall: N/A
Give the following info for a bacteria: cell structure, DNA and RNA, nucleus, ribosomes, organelleles, multicellular, cell wall
Cell Structure: prokaryotic
DNA and RNA: yes
Nucleus: no
Ribosomes: 70s
Organelleles: No
Multicellular: No
Cell Wall: peptidoglycan
Give the following info for a fungi: cell structure, DNA and RNA, nucleus, ribosomes, organelleles, multicellular, cell wall
Cell Structure: eukaryotic
DNA and RNA: yes
Nucleus: Yes
Ribosomes: 80s
Organelleles: Yes
Multicellular: both
Cell Wall: chitin
Give the following info for a protozoa: cell structure, DNA and RNA, nucleus, ribosomes, organelleles, multicellular, cell wall
Cell Structure: eukaryotic
DNA and RNA: yes
Nucleus: yes
Ribosomes: 80s
Organelleles: Yes
Multicellular: No
Cell Wall: No
Give the following info for a helminth: cell structure, DNA and RNA, nucleus, ribosomes, organelleles, multicellular, cell wall
Cell Structure: eukaryotic
DNA and RNA: yes
Nucleus: yes
Ribosomes: 80s
Organelleles: Yes
Multicellular: Yes
Cell Wall: No
What is a helminth?
worm-like eukaryotic parasite found in intestines
What are the 3 major morphologies of cells?Describe shape
bacillus: rod or cylinder
Cocci: sphere
Spirilla: rod that is twisted into spiral
Some cells remain in groups or clusters...describe staph, strept and diplococcus. What plane does diplococcus divide in
steph in clusters
strept in chain
diplococcus divids in one plane
What is a sulfur chemolithotroph? Give an example (name)
organism that uses sulfur by oxidizing to produce energy; Thiomargarita namibiensis
The relationship of the rate at which nutrient and waste products move in and out of the cell is ??? proportionate to size of the cell?
inversely
Why is the relationship of rate of nutrient and waste products moving in and out of the cell inversely proportionate?
bc rate is a function of membrane surface area available in comparison to volume
Nutrients can move into a cell more easily when the surface area : volume ratio is smaller/larger?
larger
Which cells, small or large, are more effective transporters and why?
small bc they have more surface area relative to volume...larger ratio
As size of cell increases, what happens to transportation rate (in and out)? Why?
decreases bc volume increase making the ratio of cell surface area : volume smaller
Cell size is limited for what? If the org needs to grow larger, what does the cell need to do?
effective transport; become multicellular
Viruses are acellular. What is the structure/makeup of virus...present nuclei acid, etc
either DNA OR RNA not both
protein coat called capsid
What virus does not have a capsid
mimivirus
A capsid is made up of smaller subunits called what?
capsomeres
Viruses are intracellular parasites only, which means what?
cannot grow or reproduce outside of a host cell...non-living
What is the struture of a viroid?
it is a single stranded piece of RNA, that appears double stranded due to intrastrand base pairing
Viroids can exist, stabley, outside a host cell...what about its structure allows this?
the intra-cellular pairing of basepairs of RNA
Viroids infet plants. How? How do they effect plants?
enter via wound in a plant; they interfer with regulatory RNA in teh plants...
Do viroids code for proteins? Any animal diseased known?
NOPE...NOPE
What are prions? (structure)
small replicating polypeptides.
Prions are infectious...name two infectious prion diseases
mad cow disease and creutzfeldt jakob diseases
How do prions infect a healthy organism?
they enter an organism and teh prion form of the protein induces teh pre-existing proteins to fold incorrectly forming misshapen proteins resulting in neurodegeneration
Explain exactly what happens in the conversion of PrPC to PrPSc
alpha helix rich PrPC converts to Beta structure rich insoluble conformer aggregates in host brain cells
Do prions contain DNA or RNA?
neither
Do viruses, prions or viroids contain a cell membrane? Which?
none
What cells produce the normal form of a prion protein?
neuronal cells
When a prion infects an organism, the abnormal protein forms aggregates in the neural cells resulting in what?
destruction of neural tissues and neurological symptoms
The cytoplasmic membrane is a thin layer that surrounds the entire cell and is composed of what?
phospholipids and protein
How wide is a cell membrane? If destroyed the itegrity of the cell is?
6-8 nm wide; destrpyed
Cell membranes are highly selective which allows for what?
concentration of metabolites and excretion of wastes
Define metabolite
product of enzyme catalyzed reaction
how are hydrophobic fatty acids attached to glycerol?
esterified
What is another term for glycerol esterified to a fatty acid?
poly-hydroxy alcohol
Explain the condensation Rxn that occurs to form a phospholipid
one or two water molecules are removed to form ester bonds btw -OH group of glycerol and -OH group off the carboxyl group of the fatty acids or phosphoric acid
The hydrophilic heads of a phospholipid, in the bilayer, are called what
glycerol phosphates
Peripheral proteins are extrinsic to the membrane and can be removed in what certain conditions?
changes in pH, ionic strength etc
Peripheral proteins are typically found on the surface of cell membrane and may also be bound to what?
integral proteins
Some peripheral proteins are lipoproteins. How are they anchored to cell membrane
by lipid tail on the amino terminus of the protein
Integral proteins span the layer of the membrane and are exposed where?
both on inside and outside of cell
Integral proteins are said to be ampipathic, which means what? Explain.
They have both hydrophobic and hydrophilic regions so that the hydrophobic regions can interact with the non-polar fatty acids of membrane, while top and bottom surfaces must be hydrophillic so they can interact with external and internal environments
Two types of integral proteins, what are they ?
transmembrane and embedded but now transmembrane
Clustering of proteins in the membrane allows for what?
grouping for interaction and grouping proteins that are similar in function
Lipid bilayer varies in thickness bc why?
accommodates proteins
Why is the bilayer called the fluid mosaic model?
phospholipds and proteins are free to move about therefore is very fluid, viscosity of motor oil
The fluid mosaic model also states that the globular proteins are oriented in a specific manner and span a highly mobile yet WHAT phospholipid bilayer?
highly ordered
Name 3 functions of the cell membrane
permeability barrier
energy conservation
protein anchor
The protein anchor of cell membrane is the site of many proteins involved in what?
transport, bioenergetics, chemotaxis
Bioenergetics involves the study of what?
energy flow through living systems
Chemotaxis is what?
movement up or down a concentration gradient
Bc the membrane barrier is highly selective, polar substances do not pass through easily...why?
non-polar, hydrophobic property of fatty acids within membrane = hydrophobic nature of membrane
Small non-polar and fat soluble substances like alcohol, benzene and fatty acids enter and exit cells by??
disolving into lipid phase and diffusing through
Can charged molecules such as amino acids, organic acids and inorganic salts pass throguh teh membrane?
no, they must be transported through
Name the water transports/gene in E.Coli
AqpZ
How do large molecules such as polysaccs, proteins and lipids enter a cell?
don't...must be hydrolyzed into smaller pieces then transported in
Eukaryotc cell membranes have what that is not found in prokaryotes? what %?
sterol; 5-25%
What is the function of sterol in euk cell membranes?
makes less flexible bc are rigid planar molecules that when joined make more stable and less flexible
Prokaryotes do not have sterol in membrane, except for what exception and why?
mycoplasma; lacks cell wall so sterol makes membrane more stable/less flexible
Molecules similar to sterols are found in prokaryotic bacteria called what?
hopanoids
Name a hopanoid found in prokaryotic membrane?
diplotene
How do archae cell membranes differ from eukaryotic and prokaryotic cell membranes
glycerol has ether linkage to hydrophobic side chain
archae lack fatty acids and have side chains that are composed of the 5 carbon repeating isoprene units
What is the diff btw ester and ether linkage?
ester is attached to a c=o where ether is c-o
Describe an isoprene unit
4 trans carbons with 1 methyl
What are the major class lipids of archae and describe, give example/name
glycerol diether, 1 glycerol with 2 ether bonds = phytanol (C20)
diglycerol tetraether, 2 glycerols with 4 ether bonds = biphytanyl (C40_
Phyntanyl and Biphytanyl are composed of isoprene units...how many?
phytanyl = 4 linked isoprene units
biphytanyl = 8 linked isoprene units
Structure of diglycerol tertraether (biphantanyl)
two covalently bonded phytanyl units
A tetraether is also known as a what?
di-biphytanyl diglycerol tetraether
Crenarchaeol is a diglycerol tetraether that consists of what?
5 and 6 carbon rings
Diglycerol tetraether produces what type of lipid membrane?
monolayer
glycerol diethers make up what lipid membrane?
lipid bilayer
Can lipid membrane layers consist of both mono and bi layers?
yes
Diglycerol tetraethers makeup a lipid monoloayer which gives it what unique characteristic? What orgs would typically have?
extremely resistant to heat denaturation; hyperthermophiles
What are the types of passive transportation into a cell?
simple diffusion and facilitated diffusion
Is simple diffusion saturable?
no
Is facilitated diffusion saturable?
yes at high concentrations of solute
What are the two main differences btw carrerier mediated transportation and simple diffusion?
carrier mediated can be saturated even at low solute concentrations
carrier mediated has high specificity
Does facilitated passive diffusion have specificty for solute?
yes
Active transport uses energy to drive solute where? What structures are involved?
against teh concentration gradient; transmembrane proteins or carriers
Name the 3 types of active transport
simple active
ABC (ATP Binding Cassette) System
Group translocation
What is used to drive simple active transport?
ion gradients and proton motive force
What is used in ABC system transport (active)?
ATP energy
What is used to fuel group translocation tranpsort (active)?
chemical modification of solute as its transported
3 classes of transport systems are simple, group translocation and ABC transport. Describe each
Simple transport: driven by energy of proton motive force = protons pull substances in with it
Group Translocation: substance is chemically modified by phosphoenolpyruvate
ABC Transport: involves periplasmic binding proteins...uses energy from ATP
Describe the structure of membrane spanning proteins
12 alpha-helices that wind back and forth through the membrane to form a channel tthrough which solute enters
Describe a transport event through a transmemebrane protein?
solute binds to protein...protein conformtation changes thus shuttling solute across membrane
What are the 3 classes or membrane spanning proteins?
uniporter
symporter
antiporter
A symporter (cotransporter) transports a substance along with another substance, of which is usually what?>
a proton
Sulfate and phosphate are symported along with what?
proton
Potassium enters the cell via which simple transport method?
uniporter
Sodium and protons enter and exit via what?
antiporter
What does lactose permease do in EColi?
symports lactose into cell with proton
What is teh best studied model of group translocation?
involves transport of glucose, mannose and fructose which are phosphorylated during transport by the phosphotransferase system
Describe the steps involved in the phosphotransferase system
phosphate from PEP (phosphoenolpyuvate) is transfered to HPr by enzyme 1 and teh product pyruvate is released. phosphate is the transferred from HPr to enzyme IIB by enzyme IIA. membrane bound enzyme IIC carries glucose across membrane where glucose becomes phosphorylated as it enters the cell
Which enzymes in phosphotransferase system are specific? Non-specific? (for a sugar)
Specific: Enzymes IIa, IIb, IIc
Non-specific: Enzymes 1 and HPr
A mutuation in enzyme I or HPr in the phosphotransferase transport system will result in what?
stopping of all transport bc non-specific
In ABC Binding cassette tranportation the periplasmic protein has high affinity for solute meaning?
it will bind even in low concentration
What provides the energy for ATP binding cassette transportation?
ATP hydrolyzing enzyme kinase
Decribe the structure of peptidoglycan
2 sugar derivatives: N-acetylglucosamine, N-acetylmuramic acid
Small groups of amino acids consisting of L and D alanine, D-glutanic acid, and either lysine of DAP (diaminopamelic acid)
What % is associated in regards to peptidoglycan in gram + and - bacteria?
+ = 90% - = 10%
DAP is with COOH
Lysine is right one with H
gram +
In a photo if the rod looks rough, is it gram + or neg? what is the rough called?
gram -, LPS layer
The peptidoglycan structure is held together how?
B(1,4) glycosidic bonds btw sugar monomers and peptide cross bridges btw rows
In a gram - bacteria, describe peptidoglycan connections
amino group of DAP forms peptide bond with carboxyl group pd D-alanine
DEscribe connection in peptidoglycan of gram + bacteria
cross linkage made of peptide interbridge
Describe the interbridge in peptidoglycan of staph aureus
5 glycine molecules called glycine pentapeptide bridge which connects lysine to terminal alanine
Describe the glycan backbone of peptidoglycan and it bonds
G-M-G-M constant = acetylglucosamine - acetylmumeric acid - bonded by B 1,4 glycosidic bonds
A tetrapeptide variation can occur in gram+ bacteria in one amino acid, which?
3...DAP or lysine
Peptidoglycan is found in all species cell walls (T/F)
false just bacteria
Which amino acid and sugar are NEVER found in eukarya or archae cell wall?
n-acetylmumaric acid and DAP
Most gram + cocci have what over DAP?
lysine
An unusual feature about the bacterial cell wall is the presence of 2 amino acids in which configuration?
D...-alanina and D-glutamic acid
Peptidoglycan is laid into cell by cables, with each cable ranginf how wide? Is each cable just one glycan strand?
50nm; no multiple
What is the difference btw teichoic and lipoic acids? What type bacteri are they found in
found in gram + bacteria
lipoteichoic acid is covalently linked to membrane lipids
teichoic acids are all membrane, well wall or capsular polymers containing polyalcohols...glycerophosphate or ribitol phosphate residues...covalently bound to muramic acid
What is partially responsible for the neg charge on a gram + cell?
teichoic acid
Teichoic acids are polyalcohols connected by ? Usually have other sugaras and what else attached?
phosphate esters; d-alanine
teichoic acid
How is peptidoglycan destroyed?
lysozyme, protein, can break the B 1,4 glycosidic bonds btw N-acetylglucosamine and N-acetylmumaric acid
When treated with lysozyme, a gram + bacteria produces what while gram - produces what?
psitive = protoplast
neg = sphereoplast
in dilute solution containing lysizyme, what happens to protoplast?
lyses
A protoplast will survive in what type of solution?
isotonic concentration
Does a spheroplast or protoplast have residual cell wall attached?
spheroplast of gram - wall does
A thermoplasma has no cell wall but has a tough membrane. what domain?
archae
Mycoplasma acts similar to what? why? lives in osmotically protected environments and contains what to toughen cell membrane.
protoplast, no cell wall, sterols
Pseudopeptidoglycan is found in what domain? What are the main differences?
archae; N-acetylglucosamine + N-acetyltalosaminuronic acid bonded by B 1,3 glycosidic bonds
Psuedopeptidoglycan is also known as what?
pseudomurein
Some archae have an S layer...what is an S layer? What does it consist of?
paracrystalline surface layer; protein or glycoprotein
Archae are naturally resistant to what?
lysozyme and penecillin
S layers usually have what type of symmetry?
hexagonal symm
Penicillin and other beta-lactam ring antibiotics inhibit the cell wall synthesis, how?
they bind to transpeptidase enzymes that catalyze cross-links...inhibits cross-linking
Gram - bacteria have an outer layer called LPS, what is the name? describe
lipopollysacc layer (outer membrane); polysaccs and phospholipids linked to form outer membrane
What are the 3 components of LPS of gam - bacteria?
o-specific polysacc
core polysacc
lipid a
Lipid A is embedded into what of cell bilayer?
phospholipid portion
What anchors outer membrane to peptidoglycan of gram - bacteria? Where are they located?
lipoproteins; inner side of LPS
Endotoxins found in lipid A of LPS layer of gram - bacteria are toxic to animals. What symptoms are associated? Presence in blood can lead to what?
fever, high blood pressure, activation of inflammtion and coagulation of blood; septicemia
What part of LPS blocks hydrophobic and hydrophillic moleciule
hydrophobic blocked by o polysaccs, phillic blocked by lipid regions (lipid a phospholipid layer)
Proteins are already present in periplasma and are allowed in via?
sec-protein exporting system
Porins are made of 3 identical subunits and are transmembrane proteins that allow water into which type of cell? gram -/+?
gram -
What is the diff btw a capsule and slime layer?
slimy sticky secreted layer of protein or polysacc
capsule: org in tight layer like an envelope around a cell
slime layer: more diffuse and easily deformed
Nonpathogenic microbes bind to things in nature and form a thick layer of cells called?
biofilm
Pathogenic microbes bind to?
cell surface of human tissues and involves surface polysaccs
Wjhat are the functions of fimbrae and pilli?
facilitation of genetic transfer (cogugation)
adhesion of pathogens to specific hst tissues
what are the structural diff btw fimbrae and pilli?
fimbrae are numerous, look like flagella but are much shorter
pilli are a bit longer than fimbriae and are usually only 1 on cell surface
Define congugation?
genetic transfer via cell to cell contact
Name teh parts of an endospore and what they actually are
exospore = protein
spore coat = protein
cortex = peptidoglycan
core = spore protoplast
What is found in endospore core and not in vegetative cells? Function of?
diplicolinic acid; causes dehydration, forms Ca linkages btw DNA bases and stabilizes DNA to prevent denaturation
About this deck
By: Jaclyn Anderson
Textbook: Biology Of Microorganisms 11th
Created: 2011-10-15
Size: 158 flashcards
Views: 18
Textbook:
Biology Of Microorganisms 11thCreated: 2011-10-15
Size: 158 flashcards
Views: 18
About StudyBlue
STUDYBLUE makes things that make you better at school.
Things like online flashcards with photos and audio.
Things like personalized quizzes and friendly reminders about when (and what) to study next.
Think of it as a digital backpack™: access to all of your study materials online and on your phone.
STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.
“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis
Dennis