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cell theory
1. all living things are composed of cells
2. the cell is the basic functional unit of life
3. cells arise only from preexisting cells
4. cells carry genetic info in the form of DNA, this genetic material is passed from parent to daughter cell
viruses contain genetic material but
cannot reproduce on their own
prokaryotic organisms
single celled
eukaryotic organisms
unicellular or multicellular
prokaryotic cells do not contain
-nucleus
-membrane bound organelles
eukaryotic cells have a
true nucleus enclosed in membrane
each cell has a membrane enclosing a semifluid ____ in which the organelles are suspended
cytosol
membrane of eukaryotic cells consists of
phospholipid bilayer
the phospholipid bilayer
-surfaces are hydrophilic (for aqueous environment)
-inner portion is hydrophobic (selective barrier)
cytosol allows for
diffusion of molecules throughout the cell
genetic material is encoded in ___ which is organized into _____
DNA, chromosomes
mitosis
-common to all eukaryotes
-daughter cells contain same number of chromosomes as parent cell
meiosis
-occurs in eukaryotic organisms that reproduce sexually
-produces gametes that have half as many chromosomes as the other cells in the organism
-each gamete is unique bc parent cells dna shuffles before division
binary fission
-how prokaryotic cells replicate
-requires replication of cells chromosomes
nucleus
has all genetic material needed for replication
nucleus is surrounded by
nuclear membrane or envelope
nuclear membrane or envelope
a double membrane that has a nuclear environment separate and distinct from the cytoplasm
nuclear pores
-in the nuclear membrane
-allow selective 2-way exchange of material between the cytoplasm and nucleus
DNA has coding regions called
genes
linear DNA is wound around organizing proteins known as ___, and then further wound into linear strands called ____
histones, chromosomes
nucleolus
-subsection of nucleus
-where ribosomal RNA (rRNA) is synthesized
mitochondria outer membrane
barrier between cytosol and inner environment of mitochondrion
mitochondria inner membrane
contains the molecules and enzymes of electron transport chain
mitochondria inner membrane is arranged into unfolding called
cristae (increase surface area available for electron transport chain enzymes)
space between inner and outer membrane of mitochondria is called
intermembrane space
space inside inner membrane of mitochondria is called the
mitochondrial matrix
the pumping of protons from the _____ to the _____ establishes the proton-motive force
mitochondrial matrix, intermembrane space
proton-motive force
force that promotes movement of protons across membranes down the electrochemical potential
protons in proton-motive force
flow through ATP synthase to generate ATP during oxidative phosphorylation
mitochondria are semi-autonomous because they
contain some of their own genes and replicate independently of the nucleus via binary fission
the transmission of genetic material independent of the nucleus is called
cytoplasmic or extranuclear inheritance
mitochondria releases enzymes from the _____ to kickstart apoptosis
electron transport chain
lysosomes
-membrane bound
-contain hydrolysis enzymes that can break down substrates (including substances ingested by endocytosis and cellular waste products)
lysosomes function alongside ___
endosomes
endosomes
transport, package, and sort cell material traveling to and from the membrane
endosomes can transport materials to the ____, the ____, or to the _______ for degradation
transgolgi, cell membrane, lysosomal pathways
lysosomes releasing hydrolytic enzymes can result in a process known as
autolysis (resulting in apoptosis?)
endoplasmic reticulum (ER)
-series of interconnected membranes
-borders nuclear envelope
rough ER (RER)
studded with ribosomes that permit translation of proteins destined for secretion into its lumen
smooth ER (SER)
-no ribosomes
-used for lipid synthesis (phospholipids in cell membrane)
-used for detoxification of certain drugs and poisons
-transports proteins from the RER to the golgi apparatus
golgi apparatus
-stacked membrane-bound sacs
-receives materials in vesicles from ER
-may modify cellular products (by adding carbohydrates, phosphates, or sulfates, or signal sequences)
signal sequences
direct product to specific location
after golgi modifies and sorts, products are
repackaged in vesicles, and then directed to correct location
if product is to be secreted, _____ merges with _____, and its contents are released via endocytosis
secretory vesicles, cell membrane
peroxisomes
-contain hydrogen peroxide
-breaks down very long chain fatty acids via beta-oxidation
-synthesis of phospholipids and contain some enzymes involved in the pentose phosphate pathway
cytoskeleton
-provides structure to cell and maintain shape
-provides a conduit for the transport of materials
3 components of cytoskeleton
1. microfilaments
2. microtubules
3. intermediate filaments
microfilaments
-made of actin
-plays role in cytokinesis
cytokinesis
division of materials between daughter cells
actin filaments are resistant to ____ and ____
compression, fracture
actin filaments can use ATP to generate force for movement by interacting with ____
myosin
during mitosis, the _____ is formed from microfilaments (during cytokinesis)
cleavage furrow
steps of cytokinesis
1. cleavage furrow formed
2. organizes as ring at site of division
3. as actin filaments contract, ring becomes smaller
4. pinches off connection
microtubules
-hollow polymers of tubulin proteins
-provide pathways for kinesin and dynein (to carry vesicles)
cilia
projections from a cell involved in movement of materials along surface of cell
flagella
structures involved in movement of cell itself
cilia and flagella are composed of
9+2
-9 pairs of microtubules forming outer ring
-2 microtubules in center
9+2 structure is only seen in
eukaryotic organelles of motility
centrioles are found in
centrosomes
centrioles
organizing centers for microtubules
centrioles are structured as
9 triplets of microtubules w a hollow center
during mitosis, centrioles…
migrate to opposite poles of dividing cell and organize mitotic spindle
the microtubules emanating from the centrioles attach to
the chromosomes via complexes called kinetochores and pull apart sister chromatids
intermediate filaments
-filamentous proteins (keratin, desmin, vimentin, lamins)
-cell-cell adhesion
-maintenance of integrity of cytoskeleton
-anchor other organelles
intermediate filaments can withstand
tension
types of tissue
-epithelial
-connective
-muscle
-nervous
epithelial tissue
-covers body and lines its cavities
-provides protection
-sometimes involved in absorption, secretion, and sensation
epithelial cells are tightly joined to
each other and to basement membrane
basement membrane
underlying layer of connective tissue
epithelial cells constitute the
parenchyma
parenchyma
functional parts of organ
epithelial cells are polarized:
-one side faces a lumen or outside world
-other side interacts with underlying blood vessels and structural cells
lumen
hollow inside of an organ or tube
simple epithelia
one layer of cells
stratified epithelia
multiple layers of cells
pseudostratified epithelia
one layer of cells but looks like multiple layers
cuboidal cells
cube shaped
columnar cells
long and thin
squamous cells
flat and scale-like
connective tissue
-supports the body and its framework
-for epithelial cells to carry out their functions
connective tissue is main contributor to the
stroma
stroma
support structure
examples of connective tissue
bone, cartilage, tendons, ligaments, adipose tissue, blood
most cells in connective tissues produce and secrete materials such as
collagen and elastin (to form extracellular matrix)
prokaryotes contain genetic material in
single circular molecule of DNA in nucleoid region
prokaryotes carry out electron transport chain using
the cell membrane
prokaryotic ribosomes are (smaller/larger) than eukaryotic ribosomes
smaller
3 overarching domains of life
-eukarya
-archaea (prokaryote)
-bacteria (prokaryote)
archaea
-extremophiles
-often use chemical sources of energy
extremophiles live in harsh environments such as
-high temp
-high salinity
-no light
chemosynthesis
getting energy from chemical sources
photosynthesis
get energy from light
archaea similarities to eukaryotes
-start translation with methionine
-similar RNA polymerase
-histones
archaea similarities to bacteria
-single circular chromosome
-divide by binary fission or budding
bacteria’s relationship w humans
-mutualistic symbiosis
-pathogenesis
bacteria shape classifications
-cocci
-bacilli
-spirilli
cocci
spherical bacteria
bacilli
rod-shaped bacteria
spirilli
spiral-shaped bacteria
bacteria metabolic processes classifications
-obligate aerobes
-obligate anaerobes
-facultative anaerobes
-aerotolerant anaerobes
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Flashcard (107)