Studied by 165 people
Ch. 6, Ch. 7, Ch. 36
cell theory
all living matter is composed of one or more cells
the cell is the structural and functional unit of life
all cells come from other cells
prokaryotic
no nucleus
eukaryotic
nucleus
why are cells small?
favorable SA:V ratio (like in lab)
metabolic requirements
what’s not in a animal cell?
chloroplast
central vacuole
cell wall
whats not in a plant cell?
lysosomes
centrioles
what is the cytoplasm?
in between the cell membrane and nucleus, the “fluid part” of the cell
what is the nuclear membrane?
its a double membrane that surrounds the nucleus
what is the inner part of the nuclear membrane made of?
a protein matrix— gives the nucleus its shape
what are nuclear pores?
holes through both nuclear membranes, allows things to go in and out of the nucleus
what is the nucleolus?
its the place where DNA is stored in the nucleus, the park that is the dark color
what is chromatin?
chrom = colored
tin = threads
the thing that helps to form chromosomes in cells
what does the nucleus do?
store genetic info, control center of cell
what are ribosomes?
made of protein and rRNA
no membrane
does protein synthesis
where are ribosomes?
chilling in cytoplasm (making protein for cytosol) OR membrane-bound (they make protein and smth else ships it away)
whats the endomembrane system?
membranes connected through touching each other OR through the transfer of segments through vesicles
cells are an endomembrane system?
whats the endoplasmic reticulum?
makes up half of the cells
often continuous with the nucleus membrane
there is smooth ER and rough ER
smooth ER
no ribosomes
creates lipids (lipid synthesis)
stores carbs
detoxification of poisons
rough ER
has ribosomes
makes (secretory) proteins
what does the gogli apparatus look like?
stack of pita bread (made of cisternae)
cis face of golgi…
receives
trans side of golgi…
ships
what does the golgi do?
processes (modifies ER products)
ships (packages and sends ER products)
what are lysosomes?
single membrane
made from golgi
breaks down cellular material with enzymes (important in cell death)
vacuole structure
single membrane
bigger than golgi
what are the types of protists vacuoles?
contractile, food, plant central
contractile vacuoles function
pump out water
food vacuole function
store ingested food until lysosomes digest it
plant central vacuole
very large single vacuole (90% of the plant cell) and stores water/other ions and pigments
mitochondria structure
2 membranes— inner has more surface area than outer
mitochondria function
cell respiration: the release fo energy from food
ATP generation
powerhouse of the cell
chloroplast structure
2 outer membranes
complex internal membrane
fluid-like stroma found in inner membrane
contains the green pigment in chlorophyll
chloroplast function
photosynthesis
endosymbiont theory
eukaryotes are prokaryotes and they become dependent on each other —> evolved into a single organism
byproduct of the eating was mitochondria and chloroplast
peroxisomes
single membrane
break down peroxides
sometimes break down alcohols or fatty acids
who has a cell wall?
plants, prokaryotes, fungi, some protists
what makes up the cytoskeleton?
microtubules, microfilaments, intermediate filaments
what are microtubules?
thickest of the three
made of hollow rods tubulin
can grow or shrink
what are microtubules main job?
movement
it also helps to move chromosomes in cell division (makes up spindle)
what assists tubulin in movement?
dynien
how do microtubules move things?
Cilia and Flagella
what is cilia?
small things that cover like the entire cell and aid in movement
what is flagella?
long thing that helps the cell move, usually only a few
what are microfilaments?
thinnest of the three
made of intertwined actin
can grow or shrink
what are microfilaments main job?
tension
in what ways do microfilaments utilize tension?
support cell shape
cleavage furrow
muscle contractions (aided by myosin)
what is the cleavage furrow?
the in between state of cell division
what are intermediate filaments?
intermediate in size
supercoiled
very sturdy
what is the extracellular matrix (ECM)?
meshwork of things outside animal cells
outside cell membrane
what does the ECM do?
varies from cell to cell but it:
holds cells together
contributes to cell behavior and communication
helps coordination of tissues
what is the cell junction in plant cells?
plasmodesmata
what is the plasmodesmata?
a channel between plant cell walls
joins internal environments
allows the movement of water and other small solutes
what are the cell junctions in animal cells?
gap junctions, desmosomes, tight junctions
what are gap junctions
a channel between animal cell walls
joins internal environments
allows the movement of water and other small solutes
what are desmosomes?
coordinate movement by connecting intermediate filaments of two cells
what are tight junctions?
fuse adjacent cell membranes (like a pinch)
seal the space between cells
prevents leakage
what does amphipathic mean?
has hydrophobic and hydrophilic part
what model does the cell membrane take?
fluid mosaic model
what is the fluid mosaic model?
means that cell membrane is fluid and has a mosaic of proteins
what are the types of movement on the cell membrane?
lateral (very common)
flip-flopping (uncommon)
what does cholesterol do in the cell membrane?
acts as a buffer, usually helps to saturate the membrane but at cold temps it keeps them spread apart
when the cell membrane is unsaturated it is…
fluid
when the cell membrane is saturated it is…
viscous
cholesterol is a…
steroid
the cell membrane is…
selectively permeable
what types of things can make it through the cell membrane?
small non-polar things, for example:
hydrocarbons or CO2/O2
isotonic
same amount of concentration
hypotonic
lower concentration
hypertonic
higher concentration
moving with the concentration gradient is the equivalent of moving…
from high —> low concentration
what is osmosis?
the passive diffusion of water across the membrane
lysed
too much water enters, bursts
shriveled
too much water exits, shrivels
flaccid cell
weak cell
plasmolyzed cell
very very weak cell
what is osmoregulation? is it found in all cells?
pumps built into some cells that help regulate water concentration
what are transport proteins?
allow for polar molecules to pass through the membrane
what are the types of transport proteins?
Channel and Carrier
what is the transport protein specific to water?
aquaporis or smth like that
are channel proteins active or passive?
passive
are carrier proteins active or passive?
both; active when going against the gradient, passive when flowing with the gradient
what is cotransport?
when you couple the downhill diffusion of one substance with the uphill diffusion of another
what are the types of bulk transport?
endocytosis and exocytosis
what is exocytosis?
the exiting of a substance from a cell
what is exocytosis?
the engulfing of a substance to the cell
what are the types of endocytosis?
Phagocytosis, Pinocytosis, receptor-mediated
what is phagocytosis?
the engulfing of large food particles
what is pinocytosis?
the engulfing of large amounts of fluid
what is receptor-mediated exocytosis?
the engulfing of a substance only when that substance attaches to a receptor
what were the byproducts of plant evolution?
taller plants and bigger leaves bc it = more sunlight
need for better anchorage
more evaporation—> better transport system
what is the xylem?
the tube of the tree
transports water and minerals from roots to shoots
what is the phloem?
transports the products of photosynthesis (sugars, amino acids, minerals) from where they are made (source) —> where they are needed (sink)
what are the two major pathways of transport in plant cells?
apoplast and symplast
what is apoplast?
transport outside the cell/external to the main parts of the cell
what is symplast?
transport within the cell/through the entire mass of the cytosol and plasmodesmata
how do plants transport solutes short distances?
very similar to animal cells:
both active and passive transport
uses pumps (lotta proton pumps)
uses transport proteins (specifically A LOT of aquaporins)
how do plants transport water short distances?
osmosis but the direction of flow is determined by water potential (takes pressure into consideration)
what is water potential?
the ability for water to do work/its potential energy
unit is megapascals (MPa)
solute potential + pressure potential
what is a typical plant cells MPa?
0.50
what is solute potential?
molarity (pure water = 0)
when solute concentration increases, solute potential decreases
number always negative
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Flashcard (43)