list the four concepts of cell theory
1.basic structural and functional unit 2. organisms activity is based on cells activity 3. biochemical chemical activty determines & is determined by subcellular structure 4. continuity of life is based on cell reproduction
describe three diffferent cell shapes
cubelike, disk shaped, tilelike, spherical, branching, cylindical
name the trhee MAJOR parts of any cell
plasma membrane, cytoplasm, nucleus
define generalized or composite cell
model that describes a cell in terms of common features/ functions that all cells share
does non polar mean hydrophobic or hydrophilic
hydrophobic
what is the structural significance of microvilli
to increase the surface area of the palsma membrane
what type of cell functions does the presence of microvilli typicalls indicate
found on cells involved in secretion and/or absorption
what protien acts as a microvilli stiffener
actin
name two factors in addition to special membrane junctions that help hold cells together
the gylcocalyx and tongue in groove folding of adjacent plasma membranes
which cell junction forms an impermiable barrier
tight junction
which cell junction is buttonlike adhesion
desmosome
which junction has linker protiens spanning the intercellular space
desmosome
which cell junction allows direct passage from one cells cytoplasm to the next
gap junction
what name is given to the transmembrane proteins that allow this direct passage
connexons
engulfment process that require ATP
exocytosis, phagocytosis, receptor-mediated endocytosis, solute pumping
driven by molecular energy
diffusion - simple , diffusion -osmosis
moves down (with) a concentration gradient; requites a carrier
solute pumping
moves up (against) a concentration gradient; requires a carrier
solute pumping
uses a clathrin- coated vesicle (pit)
phagocytosis, pniocytosis, receptor mediated endocytosis
typically involves coupled systems; that is ,symports or antiports
slolute pumping
examples of vesicular transport
exocytosis, phagocytosis,pinocytosis, receptor-mediated endocytosis
a means of bringing fairly large particles into the cell
phagocytosis
used to eject wastes and to seperate cell products
exocytosis
plasma membrane
a) location- external boundry of the cell b) function- confines cell contents, regulates entry and exit of materials
lysosome
a) location- scattered in cytoplasm b) function- digests ingested materials and worn out organelles
mitochondria
a) location - scattered throughout the cell b) function- controls release of energy from foods forms ATP
microvilli
a) location- projections of the plasma membrane b) function - increase the membrane surface area
golgi apparatus
a) location - near the nucleus {in the cytoplasm} b) function- packages protiens to be exported from the cell; packages lysosomal enzymes
centrioles
a) location - two rod shaped bodies near the nucleus b) spin the miotic spindle
smooth ER
a) location- in the cytoplasm b) function- site of steroid synthesis and lipid metabolism
rough ER
a) location- in the cytoplasm b) function- transports proteins (made on its ribosomes) to other site in the cell; site of membrane lipid synthesis
ribosomes
a) location- attached to Er membranes os scattered in the cytoplasm b) function- sythesize proteins
cilia
a) location -extensions of cell to exterior b) function- act collectively to move substances scross cell surface in one direction
microtubules
a) location- internal structure of centrioles; part of the cytoskeleton b) function importnat in cell shape, suspend organelles
peroxisomes
a) location - throughout cytoplasm b) function detoxify alcohol and free radicals accumulating from normal metabolism
microfilaments
a) location - throughout cytoplasm; part of cytoskeleton b) function -contractile protein (actin) moves cell or cell parts, core of microvilli
intermediate filaments
a) location - part of cytoskeleton b) function act as internal "guy wires" help form desmosomes
inclusions
a) location - dispersed in the cytoplasm b) function - provide nutriens, represent cell waste products,etc.
prophase
a. chromatin thickens to form chromosomes b. spindle apparatus form c. nuclear membrane dis appears d. nucleolus disappears
metaphase
chromosomes line up in the middle of the cell
ananphase
chromosomes are pulled to opposite poles by the spindle fiberse
when does cytokinesis begin
during anaphase
telophase
a. chromatin thins b. spindle apparatus disapear c. nuclear membrane appearrs d. nucleolus appears
osmosis
movement of water from high to low concentration
tonicity
ability of a solution to cause a cell to shrink of swell
isotonic
a solution with the same solute concentration as that of the cytosol --- stays the same
hypertonic
a solution having greater solute concentration than that of the cytosol --- cell shrivels
hypotonic
a solution having lesser solute concentration than that of the cytosol --- cell expands and bursts
phagocytosis
pseudopods engulf solids and bring them into cells interior
pniocytosis
the cell gulps drops of extracellular fluid containing solutes into tiny vessicle
exocytosis
the cell getting rid of waste -hormone secretion, neurotransmitter releases, mucus secretion, ejection of wastes
G1
cell growth - reaady for DNA replication
S
DNA replication
G2
cell growth - ready for motosis , The final period of interphase during which the cell prepares for mitosis.
GO phase
a phase of the cell cycle in which the cell is not dividing and its DNA is not replicating
mitosis
cell division in which the nucleus divides into nuclei containing the same number of chromosomes
leading strand
the new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' --> 3' direction
lagging strand
A discontinuously synthesized DNA strand that elongates in a direction away from the replication fork.
stages of mitosis
prophase, metaphase, anaphase, telophase
cleavage furrow
The first sign of cleavage in an animal cell; a shallow groove in the cell surface near the old metaphase plate.
miosis
(genetics) cell division that produces reproductive cells in sexually reproducing organisms