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81 terms

4- Characteristics of Prokaryotic and Eukaryotic Cells

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organelles
little organs inside the cell
phototaxis
movement toward/away from light
chemotaxis
movement toward/away from substances
prokaryotic cells
divided into domain Bacteria and domain Archaea (old)
difference in Bacteria and Archaea
what cell wall consists of, where they live
size of proK
.5-2.0 µm
shapes of proK
coccus, bacillus, spiral, pleomorphism
coccus
round shape
bacillus
rod shaped, oval
spiral
vibrio, spirillum, spirochete
vibrio
comma shape
spirillum
ridged, wavy shape
spirochete
corkscrew, twisted on themself
pleomorphism
bacteria vary widely in form even w/in a single culture
arrangement of proK by the groups of cells
diplo- pairs; strepto- chains; tetrads- 4 cells in a cube; sarcinae- 8, 16, 32 cells in a cube (3D); staphylo- grapelike cluster; palisade- matchsticks; trichomes- bricks; other arrangements- sq, star, rect, filaments
proK division by
binary fission- new cell wall material grows, cell pinches in half through this area; inside the chromosome has duplicated, one found in ea daughter cell; not meiosis nor mitosis
structure of proK
cell wall, components, cell membrane, internal structures, external structures
cell wall of proK
semi-ridged structure
function of cell wall in proK
maintain cell shape; prevent cell from bursting when taking in fluid; in some bacteria, it protects that bacteria from antibiotics
components of proK
differ in Gram+ and Gram- cells; peptidoglycan, outer membrane, periplasmic space
peptidoglycan
murein; polymer; most important component of the cell wall; made of 2 sugars- acetylglycosamine (gluNAc) and N-acetylmuramic (murNAc), which are attached to 4 AA (tetrapeptide). these are attached to ea other by crossed linked peptide bonds, these differ in ea species
Gram-
when peptidoglycan layers are thin
Gram+
when peptidoglycan layers are thick; also have teichoic acid- attachment site for bacteriophages, passageway for movement of ions in/out of the cell
outer membrane
primarily in Gram- bacteria; acts as a coarse sieve- controls movement of certain proteins from the environment; lipopolysaccharide
lipopolysaccharide (LPS)
endotoxin; stays w/in cell until it dies, then toxin released, used to identify Gram-, causes fever and dilates blood vessels; decrease blood pressue
periplasmic space
gap in wall of Gram-, very active, holds peptidoglycan, contains digestive enzymes and transports proteins
acid fact bacteria
mycobacteria; 60% lipids; contains much less peptidoglycan; grows slowly, can be stained by Gram stain; stains purple
wall deficient organisms
mycoplasma; have no cell wall; cell membrane contain sterol; vary widely in shape; must be grown differently; wont grow in agar
porins
form channels through the outer membrane, control ions that enter
cell membrane
fluid mosaic model; living membrane; not a solid structure; phospholipid bilayer; charged phosphate heads, hydrophilic; fatty acid tails, hydrophobic
proteins
form mosaic pattern; between phospholipid; carrier proteins- move things across membrane, goes all the way through; loosely attached but stationary; outer edge- id of organism; inner edge- digestive enzymes
functions of the membrane of proK
selectively permeable; produces cell wall components; assists in DNA replication; secretes proteins; carries out respiration; captures energy as ATP
internal structures of proK
cytoplasm, ribosomes, nuclear region, internal membrane systems, inclusions, endospores
cytoplasm of proK
semifluid substance inside cell; jellylike; 4/5 water, 1/5 dissolved "stuff"; chem reactions take place
ribosomes of proK
consist of RNA and proteins; site for protein synthesis
nuclear region proK
nucleoid; single-strand of circular DNA
internal membrane systems of proK
chromatophores-contain pigments for photosynthesis in cyanobacteria
inclusions
"storehouse"; granules- contain specific substances (glycogen/polyphosphate), might have metachromatic granules; vesicles- may contain gas for depth control, may contain iron
endospores of proK
not all bacterial cells can form spores; resting stage; reasons to produce spores- to save themself; can last thousands of years
sporulation
endospore formation
plasmids
circular pieces of DNA in cell; go through conjugation "bacteria sex"- not producing more but different
external structures of proK
flagella, pili, glycocalyx
flagella in proK
long, thin, helical appendages
structure of flagella in proK
basil body (attaches at cell membrane for movement), filament (made from protein called flagellin)
rotation of proK
one flagella- propellar liek to move forward/backward; runs- when many flagella are bundled together to move, last 1 sec, can move about 10X their length; tumbles- when many flagella move independently; last 0.1 sec, no forward progress
arrangements of proK
depend on type of bacteria; monotrichous- one flagella; amphitrichous- one at each end; lophotrichous- 2 or more at ends; peritrichous- all around; atrichous- no flagella; axial filaments- (like a drillbit) endoflagella, located between sheatha nd cell wall, found in spirochetes
pili of proK
tiny, hollow projections; smaller than flagella, more numerous, strawlike; conjugation pili and attachment pili
conjugation pili of proK
F pili; sex pili; where conjugation takes place
attachment pili of proK
fimbrae; hlep ahere bacteria to surfaces; help w/ disease producing aspects (pass toxin/disease)
glycocalyx of proK
made of polysaccharide; found external to the cell wall; capsule, slime layers
capsule of proK
not in all bacteria; secreted by cell wall; protection against phagocytosis
slime layers of proK
less tightly bound and thinner than capsule; protects cell from drying out; traps nutrients from environment; helps to bind cells together, helps stick to objects
eukaryotic cells
larger and more complex than prokaryotes
basic unit of life for kingdoms
animal, plants, protists, fungi
structures of eukaryote cells (16)
plasma membrane, cytoplasm, cell nucleus, mitochondria, chloroplasts, ribosomes, endlplasmic reticulum, golgi apparatus, lysosomes, peroxisomes, vacuoles, cytoskeleton, flagella, cilia, pseudopodia, cell wall
plasma membrane euK
control entry to/out of cell; encloses cell; sterol in the membrane; small surface to volume ratio that proK cells
cytoplasm of EuK
semi-fluid; less than in bacterial cells
cell nucleus of EuK
envelope, pores, nucleoplasm, nucleolus, chromosomes
nuclear envelope of euK
holds nucleus together
nuclear pores of euK
allow RNA to leave nucleus
nucleoplasm of euK
semi-fluid portion
nucelolus of euK
contains RNA; produces ribosomes
chromosomes of euK
genetic material; chromatin that is packed by histones- visible as individual pieces, ready for mitosis; chromatin (thin-like)
mitochodria of euK
powerhouse of the cell; ATP made
chloroplasts of euK
not in all eukaryotice cells; photosynthesis in plants/algae
ribosomes of euK
synthesis proteins
endopasmic reticulum of euK
site for rhibosomes; smooth- produces lipids; rough- ribosomes land to make proteins
golgi apparatus of euK
protein packaging factory (UPS of cells); produces lysosomes, helps form plasma membrane
lysosomes of euK
suicide sacks; releases digetsive enzymes to destroy cell or digest substances in the vacuoles; plant cells DO NOT have lysosomes
peroxisomes of euK
convert peroxides into H2O and O2; in plants oxidizes fats; in animals oxidizes AA
vacuoles of euK
storage areas for glycogen, starch, fats; comes and goes
cytoskeleton of euK
network of protein fibers; used for structure and movement w/in the cytoplasm; microfilaments- movement; microtubules- rigidity, keeps form
flagella of euK
whiplike structure; larger more complex than in proK; found in collapsing protists; human sperm
cilia of euK
short hairlike structures, not hollow like pili; fan back/forth; found in protists and humans (respiratory/digestive tract)
pseudopodia of euk
false feet; produce amoeboid movement; no directionality; constantly changing shape; some white blood cells
cell wall of euK
plants, algae, fungi; in protist referred to as pellicles; animals DO NOT have cell walls
endosybiosis
theory- two individual cells w/ own DNA co-habitat in the same cell. mitochondria/ chloroplast; divide independently w/in the same cell
movement across membranes
passive, active transport
passive transport
requires no energy for transport; simple- movement of particles from higher to lower concentration (air freshener); faciltated diffusion- must have protein carriers to move ions/molecules; osmosis- movement/diffusion of H2O
osmotic pressure
pressure required to prevent the net flow of water by osmosis
active transport
requires protein carriers; source of ATP; enzyme that rhe energy from ATP; endocytosis- out to in, invaginates/surround the substance---phagocytosis (cell eating), pinocytosis (cell drinking); exocytosis- out to in, secretion