Exam 2 (Ch. 4 Prokaryotic and Eukaryotic Cells) Flashcards
prokaryotic cell (4 things and ex.)
- DNA not in a membrane (no nucleus)
- very small
- cell walls have peptidoglycan
- no membrane bound organelles
ex: Bacteria
eukaryotic cell (4 things and ex.)
- DNA in a membrane (nucleus)
- larger and more complex
- cell wall when present is simple
- membrane bound organelles (golgi, lysosomes, mitochondria)
ex: animals, plants fungi
similarities in prokaryotic and eukaryotic cells (3 things)
- contain carbs, proteins, lipids, nucleic acids
- use chemical reactions to metabolize food, build protein and store energy
- contain cell membrane
advantages to prokaryotes for being small (3 things)
- reproduce quickly
- adapt easily to their env’t
- simple organization
coccus (def.)
spherical
bacillus (def.)
rod-shaped
spirillum (def.)
spiral
pleomorphic (def.)
many shapes
strepto (def.)
chains
staphylo (def.)
grape-like clusters
diplo (def.)
pairs (2)
tetrad (def.)
groups of fours
flagellum (def.)
structure used for motility
monotrichous (def.)
one flagellum at one end
amphitrichous (def.)
one flagellum and each end
lophotrichous (def.)
tuft of flagella at one or more ends
peritrichous (def.)
flagella around entire surface
movement of flagella is..
clockwise or counter clockwise
run means to
move in one direction
tumble means to
stop and change direction
taxis means
movement toward or away from a stimulus
positive taxis is
movement towards a stimulus
negative taxis is
movement away from a stimulus
chemotaxis (def.)
movement involving chemicals
phototaxis (def.)
movement involving light
geotaxis (def.)
movement involving gravity
fimbriae (3 things)
- appendage that is shorter and straighter than flagella
- 2-100s per cell
- used for attachment
pili (3 things)
- longer than fimbriae
- 1-2 per cell
- used in conjugation to attach to each other
glycocalyx is _________ in all bacteria
not present
glycocalyx (3 things)
- made of polysaccharides
- found outside the cell wall
- protects cell
all bacteria ________ a cell wall
have
glycocalyx (2 types)
capsule and slime layer
capsule (3 things)
- firmly attached to cell wall
- protects bacteria from phagocytosis
- nigrosin detects this
slime layer (4 things)
- loosely attached to cell wall
- protects from water loss
- made up of polysaccharides
- outside cell wall
prokaryotic cell wall (def.)
semi-rigid structure outside the cell-membrane
2 functions of the cell wall
protect and give shape
the cell wall is the site where
many antibiotics damage bacteria
cell walls can only be seen clearly with
an electron microscope
peptidoglycan is the __________ of the cell wall
main component
name the two monosaccharides that are in the cell wall
NAG and NAM
NAG stands for
N-acetylglucosamine
NAM stands for
N-acetylmuramic acid
how are NAG and NAM arranged
they alternate
what forms the cross bridges in a cell wall
amino acids
how many layers in a gram-positive cell wall
25-30
gram positive cell wall contains what that the negative wall doesn’t
teichoic acid
teichoic acid (3 things)
- acidic polysaccharide
- gives cells surface a negative charge
- prevents lyses
gram negative cell wall has how many layers
10 or less
negative cell wall does not have
teichoic acid
what additional layer does a negative wall have that a positive wall does not
LPS layer
where is the LPS layer located
outside the peptidoglycan
what does LPS stands for
Lipopolysaccharide
the LPS layer is _________ to humans
toxic
LPS layer is responsible for
infections and is resistant to antibiotics
cell membrane (4 things)
- structure below cell wall
- forms a phospholipid bilayer, similar to eukaryotes
- acts as a selective barrier
- site of ATP production
simple diffusion (def.)
movement of molecules from areas of high to low concentration
osmosis (def.)
diffusion of H2O across the cell membrane
solute (def.)
something added to a solvent that is dissolved
solvent (def.)
typically a liquid and this is what dissolves the solute
solution (def.)
mixture of the solvent and solute
hypotonic solution (explain)
higher concentration of H2O outside the cell and so it moves into the cell, making it so the concentration of solutes outside the cell is lower, the cell lysis (bursts)
hypertonic solution (explain)
there is a higher concentration of solutes inside the cell and so the solutes move out of the cell making it so that the concentration is higher outdid the cell. The cell cremates (shrinks)
isotonic solutions (2 things)
- cell remains intact
2. equal concentrations inside and outside of the cell
cytoplasm (3 things)
- jelly-like substance found inside the cell
- 80% water
- contains carbs, proteins, lipids, and genetic material
nucleoid (def.)
cluster of genetic material
ribosomes (4 things)
- structure that directs protein synthesis
- composed of 2 subunits
- smaller that eukaryotic ribosomes
- very numerous in cells that are actively growing
inclusions (3 things)
- large storage molecules made up of C, N, S, or P
- formed when these elements are abundant
- not always present
endospores contain a _______ cell wall
thick
endospores are produced when
nutrients are limited
endospores are able to survive conditions such as
heat, lack of water, exposure to chemicals
endospores can live for
25 million years
once conditions are favorable, endospores are converted back to their
vegetative state
the cloudier a tube is = the more…
bacterial growth there is
sporulation (def.)
process of making spores
what two can produce spores
Clostridium and Bacillus
how are spores killed
autoclave
autoclave (def.)
heat under pressure for 20 min.
