ratio of an object's image size to its real size
magnification
measure of the clarity of an image
resolution
accentuates differences in parts of a sample
contrast
first saw cell walls in 1665
Hooke
first able to visualize living cells
Leeuwenhoek
the study of cells structure
cytology
the study of the molecules and chemical processes (metabolism) of cells
biochemistry
larger components are in the pellet of test tubes after centrifugation at _________ speeds.
lower
smaller components are in the pellet of test tubes after centrifugation at _________ speeds.
higher
all cells are bounded by a
plasma membrane
_____________ cells lack nuclei and other membrane-enclosed organelles.
prokaryotic
____________ is an important parameter affecting cell size and shape.
surface-to-volume ratio
The eukaryotic cell's genetic instructions are housed in the nucleus and carried out by _________.
ribosomes
the nucleus is surrounded by the nuclear envelope, a
double membrane
the nuclear envelope is continuous with the
endoplasmic reticulum
houses chromosomes
nucleus
made of chromatin
nucleus
contains nucleoli
nucleus
ribosomal subunits are made in the
nucleoli
in the nucleus, __________ regulate entry and exit of materials
pores
two subunits made of ribosomal RNA and proteins
ribosome
ribosomes can be found in what 2 ways?
free in cytosol
bound to ER
what is the function of ribosomes?
protein synthesis
_________ regulates protein traffic and performs metabolic functions in the cell.
endomembrane system
extensive network of membrane-bounded tubules and sacs
endoplasmic reticulum
membrane separates lumen from cytosol
endoplasmic reticulum
houses the synthesis of lipids
smooth ER
houses the metabolism of carbohydrates
smooth ER
calcium storage
smooth ER
used for the detox of drugs and poisons
smooth ER
aids in synthesis of secretory and other proteins from bound ribosomes
rough ER
adds carbohydrates to glycoproteins
rough ER
produces new membrane
rough ER
made of stacks of flattened membranous sacs; has polarity (cis and trans faces)
golgi apparatus
modifies proteins, carbohydrates on proteins, and phospholipids
golgi apparatus
synthesizes many polysaccharides
golgi apparatus
in charge of sorting golgi products, then released in vesicles
golgi apparatus
a membranous sac of hydrolytic enzymes (in animal cells)
lysosome
functions to break down ingested substances, cell macromolecules, and damaged organelles for recycling
lysosome
large membrane-bounded vesicle in plants
vacuole
in charge of digestion, storage, waste disposal, water balance, cell growth, and protection
vacuole
___________ and ___________ change energy from one form to another.
mitochondria
chloroplasts
bounded by a double membrane; inner membrane has infoldings
mitochondria
infoldings of the mitochondria
cristae
the function of the mitochondrion
cellular respiration
typically two membranes around fluid stroma, which contains membranous thylakoids stacked into grana (in plants)
chloroplast
the function of chloroplasts
photosynthesis
specialized metabolic compartment bounded by a single membrane
peroxisome
contains enzymes that transfer hydrogen to water, producing hydrogen peroxide as a by product which is then converted to water by other enzymes in the structure.
peroxisome
what are the 3 roles of the cytoskeleton?
support
motility
regulation (signal transmission)
_______ shape the cell, guide organelle movement, and separate chromosomes in dividing cells.
microtubules
two motile appendages containing microtubules
cilia
flagella
primary __________ also play sensory and signaling roles
cilia
thin rods functioning in muscle contraction, amoeboid movement, cytoplasmic streaming and microvillus support.
microfilaments
support cell shape and fix organelles in place
intermediate filaments
a network of fibers that organizes structures and activities in the cell
cytoskeleton
made of cellulose fibers embedded in other polysaccharides and proteins
plant cell walls
cellulose deposition is oriented along...
microtubules
animal cells secrete glycoproteins that form the
EMC (extracellular matrix)
functions in support, adhesion, movement, and regulation
ECM
plants have _________ that pass through adjoining cell walls
plasmodesmata
animal cells have tight
junctions
desomosomes
gap junctions