3: Functional Anatomy of Prokaryotic and Eukaryotic Cells Flashcards
structurally different, not chemically different types of living cells
prokaryotes and eukaryotes
genetic material is typically once circular chromosome, not enclosed inside membrane
prokaryotes
no histone proteins associated with their DNA
prokaryotes
no membrane bound organelles
prokaryotes
cell walls containing peptidoglycan
prokaryotes
divide by binary fission
prokaryotes
multiple chromosomes inside a membrane-bound nucleus
eukaryotes
histones proteins associated with their DNA
eukaryotes
membrane-bound organelles
eukaryotes
if they have cell walls, it is NOT made of peptidoglycan
eukaryotes
cell division by mitosis
eukaryotes
have sticky glycocalyx surrounding them
both prokaryotes and eukaryotes
forms the biofilm of prokaryotes and eukaryotes
glycocalyx
prokaryotes include which microbes?
bacteria (peptidoglycan) and archaea (lack peptidoglycan)
round or spherical
coccus
rod shaped
bacillus
bacilli which look like cocci
coccobacilli
spiral shaped or corkscrew shaped
spiral
varies in shape
pleomorphic
pairs
diplococci
chains
streptococci
packet of four
tetrads
packets of eight
sarcinae
irregular clusters
staphylococci
pairs
diplobacilli
chains
streptobacilli
resemble cocci
coccobacilli
gelatinous polymer (usually polysaccharide) that surrounds some bacterial cells and can contribute to biofilms
glycocalyx
glycocalyx is firmly attached
capsule
protects a bacterium from being phagocytized. how can it be detected?
capsule detected with negative stain
glycocalyx is loosely attached
slime layer
both capsules and slime layers can help bacteria attach to surfaces by acting as:
adhesins
most important virulance factor
ability to form capsule
flagella
used for propulsion, important in disease (ascending UTIs)
single flagellum at one pole
monotrichous
multiple flagella at both ends
amphitrichous
multiples flagella at one end
lophotrichous
flagella all over
peritrichous
movement of microbe toward or away from particular stimulus
taxis (chemotaxis, phototaxis)
bundles of fibrils that spiral around the cell. rotation of these filaments causes corkscrewing motion which helps propel it through thick environments
axial filaments
spiral-shaped bacteria with axial fimanets
spirochete treponema pallidm (syphilis
shorter, straighter, and thinner than flagella. not for motility. for attachment to surfaces
fimbriae
which microbe uses fimbriae to attach to mucous membranes
gonorrheal bacteria
longer than fimbriae and usually have only 1-2 per cell. used for twitching or gliding motility
pili
function to transfer genetic material from one bacterium to another
sex pili
transfer of genetic information via sex pili
conjugation
semirigid and responsible for characteristic shape of the cell. composed of peptidoglycan
prokaryote cell wall
organisms whose cell wall contains many layers of peptidoglycan, forming a thick, rigid structure. also contains teichoic acids
gram positive (blue)
what antibiotic is useful in the treatment of gram positive bacteria due to it inhibition of formation of peptidoglycan, resulting in greatly weakened cell wall, and lysis
penicillin
destruction caused by the rupture of the plasma membrane and the loss of cytoplasm
lysis
bacteria that have less peptidoglycan, no teichoic acids, and have an additional outer membrane composed of lipopolysaccharide-phospholipid-lipoprotein layer surrounding the peptidoglycan layer.
gram negative.
penicillin and lysozyme are ineffective against which bacteria
gram negative (red)
alcohol dissolves which layer in gram negative bacteria during the gram stain and allows the crystal violet to escape.
lipopolysaccharide layer
gram positive bacteria have more ___ which retains the crystal violet
peptidoclycan
helps prevent phagocytosis and can be toxic to man and animals
lipopolysaccharide
the lipid portion of the lipopolysaccharide in gram negative bacteria that causes fever, dilation of blood vessels, shock, and coagulation abnormalities in humans
lipid A or endotoxin (“gram negative sepsis” or “endotoxic shock”)
heat stable and anti-phagocytic in gram negative bacteria
lipid A or endotoxin
walking pneumonia. has little or no cell walls, making it pleomorphic.
mycoplasma pneumoniae (gram negative)
have acid-fast cell walls from mycolic acid
mycobacterium
Why wouldn’t you use penicillin to treat Mycoplasma pneumonia?
penicillin targets the peptidoglycan in the cell wall. Mycoplasma pneumonia doesn’t have a cell wall, so penicillin would be ineffective.
60% of their cell wall is a water-repelling waxy lipid that resists the uptake of dyes
acid-fast cell walls, mycobacterium
water-repelling waxy lipid in acid-fast cell walls that forms a layer outside of a thin layer of peptidoglycan
mycolic acid
can be stained with carbolfuchsin; heating enhances penetration of the stain in the cell wall, which binds to the cytoplasm, and resists removal by washing with acid-alcohol.
acid-fast bacteria, mycobacterium
naturally found in tears, mucus, and saliva
lysozyme
most susceptible to lysozyme.
gram positive bacteria
less susceptible to lysozyme
gram negative bacteria
what do gram positive bacteria form in favorable environments after exposure to lysozyme? (typically lyse if not favorable)
protoplasts, which have no cell wall
what do gram negative bacteria form in the presence of lysozyme?
spheroplasts, some of the cell wall material remains
when protoplasts and spheroplasts burst when placed in dilute environments
osmotic lysis
what category of bacteria are most likely to cause eye infections?
gram negative bacteria (not effected by lysozyme)
interferes with the synthesis of the peptide cross-bridges of peptidoglycan and weakens the cell wall
penicillin and beta-lactam antibiotics
which bacteria are most susceptible to penicillin?
gram positive
why are most gram negative bacteria not as susceptible to penicillin as gram positive bacteria
because the outer membrane inhibits the entry of the antibiotic and other substances, and gram-negative bacteria have fewer peptide cross-bridges in their peptidoglycan for it to prevent synthesis of.
why are gram negative bacteria quite susceptible to some beta-lactam antibiotics, but not penicillin?
because beta-lactam antibiotics can penetrate the outer membrane of gram negative bacteria better than penicillin
plasma (cytoplasmic) membrane or inner membrane. present in prokaryotic and eukaryotic cells. selectively permeable.
phospholipid bilayer. consistency of light olive oil. “fluid mosaic model”
proteins on the outer surface of the plasma membrane that have carbohydrates attached
glycoproteins
lipids on the outer surface of the plasma membrane that have carbohydrates attached
glycolipids
help protect and lubricate the cell and are involved in cell-to-cell interactions
glycolipids and glycoproteins
some antibiotics and antibacterial agents kill bacteria by attacking what?
the plasma membrane
the passive movement of molecules or ions from high to low concentration driven by random molecular motion of liquid or gas
simple diffusion
the random movement of microscopic particles (solutes) suspended in a liquid or gas, caused by collisions with molecules of the surrounding medium
brownian motion
transport proteins
permeases
permeases transport material from high to low concentration. passive and does not require ATP
facilitated diffusion
protein channels
aquaporins
diffusion of water across a selectively permeable membrane from high to low water concentration
osmosis
the pressure needed to stop the flow of water across a selectively permeable bag
osmotic pressure
solution osmotically balanced with the cell. (0.85%, 0.9% saline)
isotonic solution
a dilute solution low in solids and high in water (solvent)
hypotonic solution
cells in isotonic solution
cell volumes will not change
human cells in hypotonic solution
swell and burst
when cells in hypotonic solution swell and burst
osmotic lysis
black death
yersinia pestis, gram negative
why are RBCs biconcave disks?
loss of nucleus
why can bacteria survive for a time in hypotonic solution, but human cells can’t?
bacteria have a supportive cell wall
lysis of any cell
cytolysis
lysis of red blood cells
hemolysis
a concentrated solution high in solids and low in water (5% saline solution). used in food preservation.
hypertonic solution
human cells in hypertonic solution
crenate (shrink)
bacterial cells in hypertonic solution
plasmolysis and bacteriostasis
process where the plasma membrane shrinks away from the cell wall in bacteria
plasmolysis
when will penicillin NOT be effective on gram positive bacteria?
when they are dormant. they must be actively growing new cell walls
when plasmolysis inhibits microbial growth
bacteriostasis
transporter proteins transport material from low to high concentration (usually to inside the cell). essentially the reverse of facilitated diffusion. requries ATP
active transport
transporter proteins transport materials from low to high concentration (usually to inside the cell). material is changed (i.e. phosphorylation) during transport. internal membrane of bacterium is impermeable to the changed material so it cannot escape. requires ATP.
group translocation
includes everything inside the plasma membrane and consists of about 80% water with mixed in proteins (enzymes), carbs, lipids, inorganic ions, and many low-molecular weight compounds.
cytoplasm
where the main chemical reactions occur. it is thick, aqueous, semitransparent, and elastic
cytoplasm
the nuclear area (_____) contains a long circular molecule of double-stranded DNA (_________)
nucleoid, bacterial chromosome
small circles of double-stranded DNA which are not attached to the bacterial chromosome. usually contain genes that are not crucial for survival of the bacterium on a day-to-day basis, but may be crucial in some circumstances (i.e. antibiotic resistance)
plasmids, extrachromosomal genetic elements
plasmids that carry genes for antibiotic resistance
R factors
composed of 2 subunits. protein factories found in the cytoplasm
ribosomes
how do prokaryotic and eukaryotic ribosomes different? how is this medically important?
structurally. certain antibiotics can inhibit the activity of prokaryotic ribosome without affecting eukaryotic ribosomes.
which antibiotics only affect prokaryotic ribosomes?
streptomycin, erythromycin, and chloramphenicol
stored phosphate inclusion
metachromatic granules
stored carbohydrate inclusion
polysaccharide granules
stored fat inclusion
lipid inclusions
inclusions used for energy
sulfur granules
inclusions of iron oxide
magnetosomes
protect the cell against damage caused by hydrogen peroxide, which forms naturally in the cell in the presence of oxygen
magnetosomes
highly durable, dehydrated bodies, with a thick wall, which are formed inside gram positive bacteria. resistant to killing(survive boiling water for 19 hours) and may remain dormant for up to 40 million years and still undergo germination. appear colorless under gram stain.
endospores (clostridium, bacillus, bacillus anthracis)
includes algae, protozoans, fungi, higher plants, animals
eukaryotic cell
these two external structures of the eukaryotic cell can be present and used for locomotion
flagella and cilia
why are all animal cells gram negative?
they lack a cell wall
why doesn’t penicillin and other similar beta-lactam antibiotics directly hurt human cells?
because their cell walls don’t contain peptidoglycan
sticky carbohydrate covering the outer curface of the plasma membrane that strengthens the cell surface, help attach cells together, and may contribute to cell-to-cell recognition
glycocalyx
in addition to diffusion, osmosis, facilitated diffusion, and active transport, what do eukaryotes use?
endocytosis
how WBCs ingest and destroy foreign microbes
phagocytosis
‘cell drinking’. extracellular fluid along with whatever substances are dissolved in the fluid is brought into the cell by invaginations of the cell membrane
pinocytosis
when substances bind to receptors in the membrane, which then triggers the membrane to fold inward
receptor-mediated endocytosis
what do prokaryotes make to interfere with endocytosis/phagocytosis?
glycocalyx, capsule, slime layer, polysaccharide layer, lipid A
one of the ways that viruses can enter animal cells
receptor-mediated endocytosis
includes everything inside the cell membrane and external to the nucleus
cytoplasm
refers to the liquid portion of the cytoplasm
cytosol
eukaryotes have tiny rods and cylinders in their cytoplasm that together form what?
cytoskeleton
cytoskeleton provides support and movement for the eukaryotic cell’s organelles and the cells themselves
amoeboid motion or cytoplasmic streaming
where are eukaryotic ribosomes located?
free in the cytoplasm or attached to the rough ER
(____) contains cell’s DNA and is surrounded by a double membrane (_____). (____) allow the nucleus to communicate with the cytoplasm.
nucleus, nuclear envelope, nuclear pores
where are the ribosomal subunits created?
nuclei within the nucleus
DNA as a threadlike mass
chromatin
condensed DNA
chromosomes
network of canals running through the cytoplasm
endoplasmic reticulum
studded with ribosomes, the sites of protein synthesis
rough ER
synthesizes phospholipids, fats, and steroids
smooth ER
functions in the secretion and release from the cell of certain proteins, lipids, and carbohydrates
golgi complex
proteins synthesized by ribosomes on the rough ER are transported to the golgi complex via (_____) where they are then modified and packaged for release into the cell cytoplasm in (______) or for release outside the cell vie (_____)
transport vesicles, storage vesicles, secretory vesicles
contain digestive enzymes for digesting molecules or phagocytized materials
lysosomes
what produces the digestive enzymes in the lysosomes?
ribosomes
membrane bound bags created either by the golgi complex or by endocytosis
vacuoles
powerhouses of the cell which produce ATP on the inner surface of cristae. have their own ribosomes and DNA. reproduce by binary fission
mitochondria
inner mitochondrial membrane which provides enormous surface area on which chemical reactions can occur
cristae
center of the mitochondrion that is a semifluid substance
matrix
eukaryotic mitochondria with bacterial type ribosomes that can be damaged by antibiotics used in bacterial ribosomes and they have their own DNA,
support for the Endosymbiotic Theory
what antibiotic kills mitochondrial ribosomes in the bone marrow, and what disease does it cause so that a bone marrow transplant must be done?
chloramphenicol causes aplastic anemia
