Functional Anatomy of Prokaryotic Cells Flashcards by Franchez Cassandra Escander

prokaryotic cells that play an important role on human disease and health

bacteria

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has no nuclear membrane and membrane bound organelles (e.g. Mitochondria, E.R., Golgi complexes)

bacteria

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collective term for layers surrounding the bacteria

cell envelope

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found on the outer surface of the membrane, most important role is to protect the bacteria

cell wall

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cell wall consist of what

peptidoglycan

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used to differentiate whether bacteria are gram positive/negative

peptidoglycan

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have a thick layer of peptidoglycan

gram positive bacterai

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have a thin layer of peptidoglycan sandwitched between the surface membrane and plasma membrane

gram negative

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helps maintain shape of the bacteria

cell wall

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round shaped bacteria

cocci

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rod shaped bacteria

bacilli

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spiral shaped bacteria

spirilla

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bacteria with multiple forms

pleomorphic

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acts as a shield against phagocytosis and helps it adhere to surfaces

an important virulence factor

capsule

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most important layer of cell envelope, encloses the cytoplasm

plasma membrane

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gel-like substance consist mainly of water, cell components, enzymes, and various organic molecules

plasma membrane

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acquires nutrients
eliminate waste
maintains constant, organized state
selectively permeable barriers

plasma membrane

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in bacteria, this layer is important in respiration, photosynthesis, and synthesis of lipids and cell wall components

plasma membrane

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sites of protein synthesis

ribosomes

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present in cytoplasm or attached to plasma membrane

ribosomes

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ribosomes that are attached to the plasma membrane

plasma membrane associated ribosomes

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make proteins that reside in the cell envelope or proteins that will be transported outside the cell

plasma membrane associated ribosomes

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irregularly shaped region that contains the cell chromosome

nucleoid

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single circle of double stranded DNA but some can have linear and more than 1

chromosome

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small, dsDNA that can exist dependently from the chromosome (can be linear or circular) has few genes

plasmids

often contain genes that have selective advantage

plasmids

hair-like structures that allow bacteria to attach to other cells

pili

shorter pili

fimbriae

long whip-like protrusions that allow bacteria to move

flagella

when starved for nutrients, these can develop dormant,heat and dessication resistant spores

endospores

most of the knowledge of endospores came from this

Bacillus subtilis

can replicate every 30-60 minutes

B. subtilis

inititates sporulation

starvation

a strategy used by many organisms, including bacteria, fungi, protozoa, algae, and ferns to survive conditions that are too harsh to sustain vegetative growth.

sporulation

8 morphological stages of sporulation decision to use one of two potential polar division sites for septum formation what stage

replication and formation of axial filament what stage of sporulation

stage I

septation occurs what stage of sporulation

stage 2

septation product which will ultimately become the spore

forespore

septation product where forespore is derived

mother cell

mother cell membrane engulfs forespore what stage of sporulation

stage III

mother cell chromosome destruction what stage of sporulation

stage IV

made up of thick peptidoglycan layer surrounding the forespore protoplast

cortex

provide heat resistance and maintaining dormancy to the spore

cortex

deposition of coat proteins what stage of sporulation

stage V

maturation completing development what stage of sporulation

stage VI

is a component that accumulates in the forespore protoplast during spore formation, contributing to the heat resistance of the developing spore.

dipicolinic acid

what stage does the dipicolinic proliferates

stage VI

maintains dehydration in the spore

dipicolinic acid

mother cell is called what in stage VII of sporulation

sporangium

mother cell releases spore what stage of sporulation

VII

only 10-30 percent of a vegetative cell's water content

dessicated spore

protects DNA in dessicated spores

small acid soluble proteins

program to wake the dormant cell and dissolve cortex of spore

germination

two categories of cells

eukaryotic and prokaryotic cells.

means “true nucleus”

eukaryotic

eu means

true

means “before nucleus”

prokaryotic

pro means

before

Organisms which are categorized in the domains of Bacteria and Archaea belong to the ___cells.

prokaryotic cells

Fungi, animals, plants and organisms under the kingdom Protista are under the category of ___cells.

eukaryotic

which is the selective barrier between its cytosol

plasma membrane

a semifluid jelly-like substance inside

cytosol

carry the genes made of DNA (deoxyribonucleic acid) segments

chromosomes

complexes or units that convert instructions from the genes to proteins

ribosomes

which is bigger P or E?

Eukaryotes (Typically 10 – 100 μm _ Prokaryoties (Typically 1– 5 μm)

difference between prokaryotes and eukaryotes in genetic material

P - free floating in cytoplasm (nucleoid) E - contained in a membrane bound nucleus

difference between prokaryotes and eukaryotes in # of chromosomes

P - single chromosome; usually circular in shape E - multiple chromosome; generally in pairs

difference between prokaryotes and eukaryotes in presence of histone

P - absent E - present

difference between prokaryotes and eukaryotes in ribosome sizes

P - smaller (70S) E - larger (80S)

eukaryotic ribosomes (2)

70S 80S

eukaryotic ribosomes present in cytoplasm or attached to membranes

80S

eukaryotic ribosomes in mitochondria and chloroplast

70S

difference between prokaryotes and eukaryotes in membrane bound organelle

P - absent E - present

difference between prokaryotes and eukaryotes based on its cell wall composition

P - based on peptidoglycan E - (when present) is made up of cellulose or chitin

difference between prokaryotes and eukaryotes in presence of cili

P - absent E - may be present

difference between prokaryotes and eukaryotes in present of flagella and its movement

P - if present provides rotating motility E - if present provides whiplash motility

difference between prokaryotes and eukaryotes in presence of pili

P - present E - absent

a prokaryotic cell, the genetic material is usually located in a region that is not membrane closed, which is called a

nucleoid

On the other hand, the genetic material possessed by a eukaryotic cell is contained or found in a double membrane-bound organelle called the

nucleus

After some million years, after the rise of ____, eukaryotes emerged in the earth, having complex structures of organelles and can support aerobic metabolism as well as photosynthesis.

atmospheric oxygen

One good explanation on how the first simple eukaryotic cells have emerged to earth is the

endosymbiotic hypothesis

states that the mitochondria and chloroplasts, the organelles which is responsible for cellular respiration, came from a respiring prokaryote and a cyanobacterium-like prokaryote.

endosymbiotic prokaryote

possess short amounts of DNA which are in a circular form, which is common to bacteria.

mitochondria chloroplast

In the world of microbiology, the common and major groups of eukaryotes are the

protist (protozoa and algae) fungi

have a true nucleus bounded by a double-layer membrane

eukaryotic cells

function as “passageways” for messenger RNA leaving the nucleus out to the cytoplasm during the event of protein synthesis

pores in double layer membrane

The eukaryotic DNA is highly condensed and wrapped around proteins called

histones

possess a strong positive charge responsible in associating with the negatively charged phosphate groups on the DNA, giving it a more compact shape

histone

is a complex system comprised of tubes. It is an extensive network of membrane that makes up for more than half the total membrane in most eukaryotic cells

endoplasmic reticulum

endoplasmic means

within the cytoplasm

reticulum means

little net

The endoplasmic reticulum is differentiated into two types

RER SER

mainly possesses numerous ribosomes on its surface, resulting in a rough, granular appearance when seen under an electron microscope, hence, the name.

rough endoplasmic reticulum

. The areas which do not contain numerous amounts of ribosomes are known as the

smooth endoplasmic reticulum

function is to mainly synthesize protieins

RER

Proteins synthesize in the RER already have specified final destinations, which is to the

Golgi apparatus

in contrast, is involved in a large array of metabolic processes

SER

SER is involved in processes called (5)

lipid synthesis carbohydrate metabolism calcium ion storage detoxification of drugs and poisons

is a transport organelle, which consists of a set of flattened vesicles

golgi apparatus

The Golgi apparatus is a transport organelle, which consists of a set of flattened vesicles, called

dictyosomes

is responsible for the modification, storage and sending of the products formed in the endoplasmic reticulum

Golgi apparatus

, the membrane itself is extensive in cells which are specialized in secretion what organelle

Golgi apparatus

has a distinct structural directionality

Golgi stack

comprises of two sides, the cis face and the trans face.

Golgi stack

face is the part which is usually located near the ER. Transport vesicles from the ER move to the Golgi apparatus through this face

cis face

face gives rise to vesicles that “pinch off” and travel to other sites

trans face

are membrane bound organelles which contain digestive enzyme

lysosomes

contain vesicles which possess hydrolytic enzymes that are responsible for digesting waste products of the cell.

lysosomes

These hydrolytic enzymes have the potential to digest the whole cell, in a process called a

autolysis

autolysis is being regulated by enclosing the enzymes with the

lysosomal membrane

The hydrolytic enzymes and the lysosomal membrane are manufactured in the

RER

work at acidic environments, hence, not very active when released into the cell since the pH of the cytosol is neutral in nature.

hydrolytic enzymes

enzyme pH of cytosol

neutral

lysosome digesting food

phagocytosis

lysosome breaking down damaged organelles

autophagy

are generally rod-shaped organelles enclosed by a double membrane

mitochondria

The inner surface of the mitochondria is folded into finger-like projections called

cristae

These organelles vary in numbers depending on which kind of cell they are present in, sometimes in singles or may be found in large numbers

mitochondria

a are sites where cellular respiration occurs, which is the metabolic process that uses oxygen to generate ATP by extracting energy from fats, sugars, and other fuels.

mitochondria

which can be observed in plants and algae, are specialized cells which are also sites of photosynthesis

chloroplast

are flatted membranous sacs arranged into stacks called grana.

thylakoids

thylakoids arranged into stacks

grana

These thylakoids contain the photosynthetic pigment of the plant called the

chlorophyll

responsible for converting solar energy to chemical energy when it is used to synthesize organic compounds particularly sugars from carbon dioxide and water.

chloroplast

are organelles derived from the Golgi apparatus.

vacuoles

are responsible for storing various nutrients and waste products.

vacuoles

is the rigid protective layer that surrounds the cell

cell wall

Some organisms that do have cell walls are

fungi algae plants

provide form and strength to the cell

cell wall

The cell walls of algae, plants and some lower members of fungi are composed of

cellulose

chain of glucose molecules

cellulose

fungi that have a different composition of cell wall in yeast and mushroom

chitin

a polymer of N-acetylglucosamine is the primary component of the cell wall.

chitin

is also observed as a major component of crustacean and insect exoskeletons, whose functions are for strength and rigidity.

chitin

In eukaryotes without cell walls, the _____ becomes the outermost layer of the cells.

plasma membrane

acts as selective barrier which allows the passageway of important molecules into the cell.

plasma membrane

The plasma membrane is comprised of lipid structures containing

two chains of fatty acids and phosphate group

Each phospholipid molecule is composed of two regions

hydrophilic head hydrophobic tail

which is composed of the phosphate group and glycerol

hydrophilic head

which is composed of the two fatty acid chains

hydrophobic tail

It can be noticed that when a phospholipid is dropped into a body of water, a __would form

micelle

which is an aggregate with the hydrophilic head in contact with the solvent, while the hydrophobic tail is being protected inside away from the solvent.

micelle

is an extensive network of fibers that can be observed in the cytoplasm.

cytoskeleton

function is to support the cell’s shape and for mechanical support.

cytoskeleton

very important part of the cell since some eukaryotes lack cell wall

cytoskelton

cytoskeleton is comprised of three types of molecular structures

microtubules microfilaments intermediate filaments

are the main components of eukaryotic cells in regard to motility

flagella cilia

is a lash-like appendage which provides movement or locomotion in certain eukaryotic cells

flagellum

cells that have flagella

flagellates

It functions also as sensory organelles to temperatures and chemicals in the surroundings of the cell

cilia

on the other hand, can be described as short flagella. B

cilia

Both appendages are attached to the plasma membrane and the bases are anchored to the cell by a

basal body

is the classification of organisms that possess simple characteristics in their cells.

prokaryote

a type of prokaryotes, were also observed with their differences in shape and arrangement.

bacteria

three basic shapes of bacteria

rod spherical curved (spiral)

Bacterial cells also remain attached in an arrangement depending on the plane of ___, which is a characteristic of their genera

fission

some bacteria can be arranged in

pairs (diplo) groups of four (tetrad) three dimensional cubes (sarcina) chains (streptococcus) or irregular (staphylococcus)

paired cocci

diplococci

grape-like cocci

staphylococci

chains of cocci

streptococci

3D cube cocci

sarcina

groups of 4 in cocci

tetrad

Most bacteria secretes a

glycocalyx

a slimy or sticky material on their cell surface made of polysaccharide or proteins.

glycocalyx

glycocalyx that is a more organized matrix, otherwise, an easily deformed

capsule

functions as a protective layer that enables bacteria to resist phagocytosis by the host immune system

capsule

Its polysaccharide nature allows it to bind water and likely resist desiccation

capsule

what gram positive bacteria has a polysaccharide type 11, glucose, glucoronic acid, other types, various sugars and amino sugars

S. pneumoniae

what gram positive bacteria has the polysaccharides of hyaluronic acid (group A), others containing amino sugras, uronic acids

Streptococcus spp.

what gram positive bacteria has the glutamyl polypeptide

bacillus anthracis

what gram negative bacteria has the polybosephosphate

Haemophilus influenzae

which gram negative bacteria has the polysaccharides sugars such as hexoses, fucose, uronic acids

Klebsiella spp.

what gram negative bacteria has the N-acetylmannosamine phosphate polymer and sialic acid polymers

Neisseria meningitidis

The most observed extracellular structures are the

flagella

are thin hair-like structures which are used for motility of a cell, regardless whether eukaryotic or prokaryotic

flagella and motility

single flagellum at one end

monotrichous

flagellum on both end

amphitricohus

many flagella on one end

lopotrichous

numerous flagella surrounding the cell

peritrichous

As the flagellum’s function is for locomotion, it greatly relies in energy driven by the

basal body

A clockwise rotation of a single flagellum will result into “__” of the cell

tumbling

On the other hand, if the cell’s flagella rotates counterclockwise, it results in “___” to a straight line.

running

Other extracellular structure which can be noticed in a bacterial cell is the

pili

are the structures which resemble short flagella.

pili

they are not used with motility, which makes them different from the flagella

pili

used for anchorage or “sticking” of the bacterium in a specific surface

pili

Attachment pili are sometimes called

fimbriae

which is a term mostly used in order to differentiate attachment pili to a sex pili,

fimbriae

which functions in transfer of genetic information by means of conjugation.

sex pili

Similar to eukaryotes, prokaryotes also possess a

plasma membrane

Analogous to sterols of the cell membrane are

hopanoids

which strengthen the membranes of bacteria

hopanoids

have variations in their cell membranes not found in the other two domains

archaea

archaea hydrophobic sides are attached to the hydrophilic heads by what linkages

ether

archea membrane is composed of repeating units of

5-C hydrocarbon isoprene

20-C unit of isoprene

phytanyl group

40-C unit of isoprene

biphythanyl

the cytoplasmic membrane of Archaea can be constructed with

glycerol diether diglycerol tetraethers

s twice the former but the ends pointing inward become covalently linked

diglycerol tetraethers

serve its purpose to Archaeans living in extreme conditions such as the hyperthermophiles.

lipid monolayers

Among the critical functions of the prokaryote membranes are (3)

permeability barrier anchor to membrane proteins major site of energy conservation

Small uncharged molecules can pass through membranes by ____ except charged ions.

simple diffusion

while polar, does freely pass the membrane in both directions

water

dedicated transport proteins for water

aquaporins

its aquaporin adjusts movement of water across its membrane in varying osmotic conditions

E. coli

help accumulate solutes against concentration gradient, which never would occur had diffusion been the only mechanism to so.

transport proteins

consists only of a membrane spanning transport protein;

simple transport

involves a series of proteins in the transport event

translocation

consists of three components: a substrate-binding protein, a membrane-integrated transporter, and an ATP-hydrolyzing protein

ABC system

All transport systems require energy in some form, either from

proton motive force ATP

involves transport proteins such as uniporters, symporters and antiporters, whose functions is owed to their names.

simple transport

is a well-studied symporter for lactose using the energy of the protons as the driving force, which puts is in the indirect active transport category

Lac permease

transporter in E.coli that is used for lactose using energy of protons

Lac permease

modifies the substance during the uptake by phosphotransferase system.

group translocation

provide the energy (phosphate) which is cascaded from the five-protein system to glucose (sample molecule) during transport.

phosphoenolpyruvate (PEP)

are found in gram-negative and employs the periplasmic-binding proteins, membrane transporter and ATP-hydrolyzing proteins.

ATP-binding Cassette (ABS transport system)

About ___ABC transport systems have been identified in prokaryotes for the uptake of organic compounds such as sugars and amino acids, and inorganic nutrients.

200

Gram positives have ABC transport systems involving ___ proteins of their cell membranes and do the same just as in the gram negatives.

peripheral

While there is a specific area where the genetic materials of prokaryotes can be found, the absence of a nuclear membrane make it indistinguishable. It is, thus, found in an area called

nucleoid region

Generally, the nucleoid or the bacterial chromosome of the prokaryotes is constituted in a closed circular shape of what kind of DNA

double-stranded DNA

However, not all bacteria conform to a circular structure of DNA. Some bacteria also do possess linear chromosomes such as

Streptomyces coelicolor

Some bacteria also contain additional DNA in a form of

extrachromosomal plasmids

fundamental internal structures of prokaryotic cells. These structures are comprised of complex proteins and RNA.

ribosomes

the site of protein synthesis, where an mRNA is being translated into a protein

ribosomes

Foremost, ribosomes are measure with

Svedberg units

a prokaryotic ribosome has only

70s

All ribosomes are composed of two unequal subunits. Prokaryotes are comprised of a subunit of

50s and 3-s

eukaryotes are composed of what subunits

60S and 40s

Bacteria, like other prokaryotic and some eukaryotic cells such as plants, have a protective layer in their cells which provides structural rigidity and strength which are called

cell walls

protects bacterial cells against lysis

cell wall

can be caused by pressures in the activities of transport systems of the cell.

lysis

Generally, species of bacteria are divided into two major classifications in regards with their cell wall structures. These are called G

gram positive gram negative

Basically, the cell wall structure of a Gram-__bacteria is very much more chemically complex, consisting of two layers

negative

On the other hand, the cell wall of a Gram-___bacteria is comprised of only a single type of molecule but very much thicker than its counterpart

positive

is a polysaccharide which is made up of N-acetylglucosamine and N acetylmuramic acid –

peptidoglycan

amino acids in peptidoglycan

L-alanine, D-alanine, D-glutamic acid, and either lysine or DAP (diaminopimelic acid).

L-alanine, D-alanine, D-glutamic acid, and either lysine or DAP (diaminopimelic acid). Such molecules are responsible for the formation of a repeating structure called the g

glycan tetrapeptide

The chains of sugars connected by the glycosidic bonds are linked by the cross-links of

amino acids

typically obtain cross linkages by a peptide formation from the carboxyl group of D-alanine to the amino group of DAP.

gram negative

occurs through a peptide interbridge, in which the numbers and types of amino acids in that interbridge vary between species.

gram positive

In the cell wall of a Gram-positive bacteria, ____comprises about 90% in the structure itself, mostly having several sheets stacked one after another.

peptidoglycan

peptidoglycan contain acidic polysaccharides known as

teichoic acid

which contain phosphate groups that are responsible for an overall negative charge of the cell surface.

teichoic acid

This actually makes the cell wall of Gram-negative bacteria to be less sturdy.

thinner peptidoglycan

the structure is more complex because there is a second phospholipid bilayer observed outside of the peptidoglycan layer, which is more permeable than the inner cytoplasmic membrane.

gram negative bacteria

In addition, the second phospholipid bilayer contains special types of molecules called

lipopolysaccharides

which helps support the bacterial cell by protecting it from certain drugs and antibodies in the immune system.

lipopolysaccharides

This outer membrane is connected from the peptidoglycan layer by molecules called

lipoproteins

which functions as anchorage and hold the outer membrane via covalent bonds of the bacteria to itself.

lipoproteins

Moreover, one function of the outer membrane is to keep the proteins whose activities are being done outside the cytoplasmic membrane from going away. Therefore it is contained in a region between the outer surface of the cytoplasmic membrane and the inner surface of the outer membrane called the

periplasm

The reason why the outer membrane is relatively permeable to some molecules is because of channels embedded in the membrane which are known as

porins

porins are divided in two

nonspecific porins specific porins

which form water-filled channels making any small substance to pass,

nonspecific porins

which contain binding sites for specific types of molecules.

specific porins

In Gram staining procedure, the crystal violet-iodine complex forms outside/inside the bacterial cell.

inside

by applying ___, the crystal violet-iodine complex becomes extracted from the Gram-negative bacteria but not from the Gram-positive bacteria.

alcohol

dehydrates the thick peptidoglycan layer of the Gram-positive cell wall, resulting in the closure of pores in the layer itself and preventing the escape of the crystal violet-iodine complex, hence, the violet coloration.

alcohol

This makes the Gram-negative bacteria readily accept the counterstain

safranin

Certain species of bacteria, such as ___and __, produce structures called endospores.

Bacillus Clostridium

are highly differentiated, dormant forms of the cells which function as survival structures that enables the organism equipped with it highly resistant to extreme conditions such as very high temperature, harsh chemicals, pH, as well as radiation,

endospores

endospores is highly resistant to

very high temp harsh chemicals pH radiation

compartmentalized interior but no cell wall

animal cell

non-compartmentalizd in interior has a cell wall

bacterial cell

two major structures in bacterial cell

chromosomes ribosomes

has a + outer membrane in bacteria

gram-negative

has a - outer membrane in bacteria

gram positive

with no nuclear membrane

prokaryotes

single-celled, microscopic organism

prokaryotes

a bacillus-shaped bacterium 80 µm diameter; 200-600 µm long;

Epulopiscium fishelsoni

a spherical bacterium between 100 and 750 µm diameter

Thiomargarita nambiensis

generally much smaller eukaryotic cells.

prokaryotic cells

very complex despite their small size

prokaryotic cell

what size is more advantageous

small

diameter may be insufficient to house cells’ essential components – limit for small sizes

0.1 um

Higher/Lower Surface/Volume ratio support faster rate of nutrient exchange

Higher

means immediate expression of mutations - raw material for rapid growth and evolution

smaller size

example of straight rod

escherichia

example of branching rod

actinomyces

spore forming rod

bacillus

club shaped rod

corynebacterium

two cells that did not separate

diplococci

example of diplococci

neisseria

streaking will spread them in clusters

staphylococcus

is a measure of viable colonogenic cell numbers in CFU/mL

colony forming unit

Gram-positive, coccus prokaryote (dividing).

streptococcus pyogenes

Agents of: pharyngitis, food poisoning, puerperal fever (childbed fever), scarlet fever, rheumatic fever, skin and wound infections

streptococcus pyogenes

other shapes of bacterias

stellar square and flat triangular variable coccoid

pleomorphic bacterium

rhizobium corynebacterium

typical plasma membrane of prokaryotes has the ff (5)

phospholipid bilayer peripheral proteins integral proteins carbohydrates sterols (cholesterol)

phospholipid + coline =

phosphatidylcholine

seen in animal cell membranes

cholesterol

found in eucalyptus and plants

phytosterol

phytosterol is composed of

campesterol sitosterol stimgasterol

what lipid are present only in e coli

phosphatidylglycerol

not present in e. coli among human erythrocyte, human myelin, beef heart mitochondria

phosphatidylserine

present in archeal cell membrane

glycerol diether

version of fatty acid in archea

phytanyl

2 phytanyl covalently linked on their hydrophobic ends.

biphytanyl

because of this, archea can survive extreme conditions

lipid monolayer of biphytanyl

position of ___make it difficult for phospholipid to become solid at colder temperature

cholesterol

makes the bilayer less liquid in high temp

cholesterol

functions of bacterial membrane

selective permeability Protein anchor Breakdown of nutrients and production of energy DNA replication

function of bacterial membrane that prevents leakage and functions as a gateway for transport of nutrients into and out of the cell

permeability barrier

Transport systems are established in the membrane for this purpose

selective barrier

not allowed to pass in a selective barrier

charged ions

general charge of the cell is always maintained as

negative (-)

crystal violet and safranin are charged

negative (-)

odorless, colorless (replaces oxygen in RBC)

nitric oxide

function of bacterial membrane that is the site of many proteins involved in transport, bioenergetics and chemotaxis

protein anchor

function of bacterial membrane that is the site of generation and use of proton motive force

energy conservation

the free energy per mol required to move protons outward across the membrane

proton motive force

infoldings of plasma membrane in prokaryote

chromatophores/thylakoids

a type of membrane transport that does not require energy to move substances across cell membranes

passive transport

is the movement of molecules from a region of lower concentration to a region of higher concentration with the use of energy.

active transport

high to low – towards equilibrium

simple diffusion

passive diffusion is made up of

simple diffusion facilitated diffusion

diffusion with transporters (permeases) towards equilibrium

facilitated diffusion

uses ATP, Against concentration gradient For non-equilibrium; Unidirectional Ions and simple sugar

active processes

require energy in some form, either from the proton motive force, or ATP, or some other energy-rich organic compound

transport system

- could indirectly be active transport, facilitated by protons

simple transport

type of transport system in prokaryotes that is driven by energy in the proton motive force

simple transport

type of transport system in prokaryotes that has the chemical modification of the transported substance driven by phosphoenolpyruvate

group translocation

type of transport system in prokaryotes that has periplasmic binding proteins involved and energy comes from ATP

ABC system

simple facilitated transporter that is unidirectional

uniporter

movement of a molecule towards a direction facilitates movement of another molecule in opposite direction

antiporters

cotransport two molecule –same direction

symporters

what transporters are involved in indirect active transport

antiporters symporters

involves a transport system coupled to an exergonic chemical reaction, most commonly the hydrolysis of ATP

direct active transport

involves the coupled transport of solute S and ions-protons, which in this case, the exergonic movement of protons provides the energy to move the transported solute against the concentrated gradient or electrochemical potential

indirect active transport

indirect active transport is also known as

secondary active transport

enzymes /transport proteins along the cell membrane - allow protons to tag along a lactose

lac permease

lac permease is an example of

symporter

provide the energy (phosphate) which is cascaded from the five-protein system to glucose (sample molecule) during transport.

phosphoenolpyruvate

ABC means

ATP-binding casette

ABC transporters contain three interacting components

▪ periplasmic-binding proteins ▪ membrane transporter ▪ ATP-hydrolyzing proteins.

Found in gram neg and gram positive bacteria what transport

ABC transporters

Important because some bacterial enzyme are designed to function outside cell

protein export in prokaryotes

proteins designed to function outside cell

exoenzymes (amylase, cellulase, periplasmic enzymes)

which are specific in the types of proteins exported

translocases

A mass aggregates of prokaryotic chromosome

nucleoid

Composed of housekeeping genes

nucleoid

nucleoid is diploid/haploid

haploid

shape of bacterial chromosome

Supercoiled

Supercoiling is added or removed by

topoisomerases

function as energy reserves and as reservoirs of structural building blocks

cell inclusions

insoluble forms in cell

cell inclusion

function as phosphate reserves

metachromatic granules

function as glycogen and starch reserves

polysaccharides granules

function in non equilbirium, tried to put them inside the cytoplasm

polysaccharide granules

cell inclusion that function as energy reserves (2)

lipid inclusions sulfur granules

cell inclusion that function as ribulose 1,5-diphosphate carboxylase for CO2 fixation

carboxysomes

cell inclusion that function as protein covered cylidners

gas vacuoles

cell inclusion that function as iron mineral magnetite (Fe3O4)

magnetosomes

small gas-filled structures made of protein that confer buoyancy on cells.

gas vesicles

decrease the density of cells

gas vesicles

allows organisms in water to position themselves for optimum light harvesting.

gas vesicles

common in many species of cyanobacteria

gas vescicles

are intracellular particles of the iron mineral magnetite (Fe3 O4 ) that allow organisms to respond to a magnetic field

magnetosomes

structures that are external to the cell wall include

glycocalyx flagella fimbriae and pili

substances that surrounds the cells outside the cell wall

glycocalyx

May be up to 10 µm thick

glycocalyx

types of glycocalyx

capsule slime layer

- thick layer of viscous gel

capsule

amorphous glycocalyx

slime layer

Not required for viability

glycocalyx

a glycocalyx for biofilm protection and communication

extracellular polymeric substance

have a role in adherence, virulence, protection, securing nutrients, and cell-to-cell recognition.. The capsule is unstained and appears as a halo around the cell.

capsules

medical importance of capsule

inhibit ingestion and killing by phagocytes attachment can be absorbed as food against dehydration prevent moving out of nutrients

causes pneumonia if capsule is present

streptococcus pneumoniae

colonize respiratory tract if with capsule.

Klebsiella pneumoniae

For motility (taxis) About 15-20 nm thin

flagella

proteins helps identify certain pathogenic bacteria

flagellar

food borne epidemics are caused by this strain of flagellated bacteria

E.coli O157:H7

parts of flagella (3)

filament hook basal body

made of globular protein flagellin in chains to form a hollow core

filament

end of the filament

hook

anchors flagellum to cell wall and plasma membrane through series of rings

basal body

how many rings does the gram negative cell wall have

4 rings

what rings of the gram negative cell has them outside the peptidoglycan layer

L ring P ring

what rings of the gram negative cell has them outside the peptidoglycan layer

MS ring C ring

drives the flagellar motor rotation

proton motive force

An appreciable speed of about 60 cell lengths/second can be achieved.

proto motive force

how many rings does a gram positive flagellate have

2 rings

Diameter measures on 10-13 nm Rotates similarly like in bacteria Several different flagellin

Archaea bacteria

genes for this bear no resemblance to bacteria.

Archea Flagella

Appears that ATP is source of energy

Archea Flagella

Endoflagella Bundles of fibrils that arise at the end of cell With similar structure to flagella

axial filaments

its rotation propels spirochetes in a spiral movement.

axial filaments

Pattern useful in identifying bacteria.

flagellar distribution

the arrangement in which the flagella are present throughout the body of the cell, all of which are directed in different ways.

peritrichous

A single flagellum at one end or the other. These are known as polar flagellum and can rotate clockwise and anti-clockwise.

monotrichous

have multiple flagella located at the same spot on the bacteria's surfaces which act in concert to drive the bacteria in a single direction.

lopotrichous bacteria

are polar flagella located on opposite sides of the bacteria.

amphitrichous flagella

patterns of motility

reversible flagella unidirectional flagella

Both made of pilin proteins

fimbriae and pili

3 to 10 µm; few to hundreds in a cell; for attachment to environments; pellicle or biofilm

fimbriae

fimbriae helps this bacteria to colonize mucous membrane

Neisseria gonorrhoeae

9 to 10 µm; 1 to 2 per cell; required for bacterial genetic exchange during conjugation; genetically determined by sex factors or conjugative plasmids

pili

Adhesion to specific tissues May also function for twitching motility (type IV pili)

pili

what pili function for twitching motility

type IV

do not employ rotating flagella but instead creep along a solid surface by any of several possible mechanisms.

gliding motility

can occur from slime secretion or by a ratchet-protein mechanism that moves the outer membrane of the cell.

gliding motility

repeated extension and retraction of pili

twitching motility

Maintaining the cell's characteristic shape - compensates for the flexibility of the phospholipid membrane and keeps the cell from assuming a spherical shape

bacterial cell wall

Countering the effects of osmotic pressure - responsible for keeping the cell from bursting when the intracellular osmolarity is much greater than the extracellular teichoic osmolarity

bacterial cell wall

cell wall Providing attachment sites for

bacteriophage

attached to the outer surface of the wall are like landing pads for viruses that infect bacteria

teichoic acids

Providing a rigid platform for surface appendages - flagella, fimbriae, and pili all emanate from the wall and extend beyond it Contributes to virulence Site of action of antibiotics Differentiates major types of bacteria

cell wall

Thick peptidoglycan Teichoic acids (lipo and wall)

gram positive

Outer membrane (phospholipids, lipopolysaccharide, porins) Periplasmic space (thin peptidoglycan, lipoproteins, enzymes)

gram negative

connected by peptide interbridge

glycan tetrapeptide units

which gram reaction have interbridges

gram positive

bonds NAM and NAM together

peptide bonds

bonds NAM-NAG

B-1,4 glycosidic bonds

Sensitive to lysozyme found in animal secretions

B,1-4 glycosidic bonds

acidic component of gram positive cell wall

teichoic acid

links to plasma membrane

ipoteichoic acid

what teichoic acid links to peptidoglycan

wall

its outermembrane has Lipopolysaccharides (LPS), lipoproteins, phospholipids

gram negative

– contains unusual sugars, and provide stability in gram negative bacteria

core polysaccharide

antigenic (E. coli O157:H7)

o-polysaccharide

NOT a typical phospholipid Has endotoxin properties, which may cause violent symptoms in humans

lipid A in gram negative

Cause intestinal symptoms (gas, diarrhea, vomiting).

lipid A

Gel-like consistency contains various proteins involved in important cellular functions (hydrolytic, chemoreceptors)

periplasm

Channel for solutes (nucleotides, disaccharide, peptides etc.)

porins

Protection from phagocytes, and complement system. Barrier to antibiotics, lysozyme, detergents, dyes

gram negative outer membrane

Lack cell walls Sterols in plasma membrane

mycoplasma

Mycolic acid (wax) Thin peptidoglycan

mycobacterium

variations of cell wall in archea

a. Wall-less b. Walls of pseudomurein (N-acetyltalosaminuronic acid (NAT) instead of NAM). c. made of polysaccharides d. S-layer (paracrystalline)

instead of NAM, archea has what

n-acetyltalosaminuronic acid (NAT)

The backbone of pseudopeptidoglycan is linked by b-1,_bonds instead of the b-1,4 bonds of peptidoglycan

b-1,3

digests disaccharide in peptidoglycan

lysozyme

inhibits peptide bridges in peptidoglycan.

penicillin

The Gram positive cell without a wall is a

protoplast

is a wall-less Gram-negative cell.

spheroplast

forms are wall-less cells that swell into irregular shapes.

L forms

are susceptible to osmotic lysis.

protoplast and spheroplast

-resistant to Extreme Heat UV radiation Desiccation Chemical disinfectants

endospores

endospores are found in gram negative

Coxiella burnetiid

endospores are found in genera

Clostridium and Bacillus

– thin protein covering of endospore

exosporium

part of endospore that is made of spore-specific protein

spore coat

part of endospore that has loose peptidoglycan

cortex

part of endospore that has a wall, membrane, cytoplasm, nucleoid, ribosomes, and others

core

resistance factors for endospore

heat-stable enzymes Ca-dipicolinic acid (DPA) Protoplast dehydration Small acid-soluble spore protein (SASPs)

Binds free water and help dehydrate; intercalates with DNA, protect it from heat denaturation

Ca-dipicolinic acid

Increases heat resistance, H2O2 resistance, and keep enzymes inactive.

protoplast dehydration

protect DNA from ultraviolet radiation, desiccation, and dry heat and also serve as a carbon and energy source during germination.

small acid-soluble spore protein (SASPs)

reduce water availability within the endospore, thus helping to dehydrate it

calcium DPA complexes

These complexes also intercalate in DNA, stabilizing it from heat denaturation.

calcium dpa complexes

endospore morphology

central endosphore terminal endospore lateral endospore