Lecture 4: Cells Flashcards
cell
o Smallest Functional unit of human life that can function independently
o can live and function outside the body
o contains the genetic information for the entire organism o composed of molecules o can make new macromolecules o MOST can reproduce itself o has some organization to its contents
how big are cells
too small for the eyes to see
do all cells contain DNA
yes and they can utilize energy and make new macromolecules
nucleus
a membrane sack to hold DNA
eukaryotic vs prokaryotic
eu cells have a nucleus while pro cells do not
do all cells have a membrane
yes
almost all cells live in a
watery environment; all cells prefer it
phospholipid bilayer
barrier for all cells
plasma membrane
o Site of communication with external environment
o Separates the cell’s internal environment from external
o Plasma membrane is selectively permeable
o Controls entrance and exit from the cell
o Layer of non-polar lipids between two aqueous environments
o Surrounds all cells (cytoplasm)
o Functional unit of the plasma membrane is a single phospholipid molecule
can take on various shapes
membrane is amphipathic
has both hydrophobic and hydrophilic regions
polar glycerol head and two non polar long fatty acid tails
in a watery environment phospholipids
arrange themselves tails together and heads facing out aka a phospholipid bilayer
cytosol
watery environment inside cell
membranes for internal organization
only eu cells
cell walls
provide shape and prevent over filling
who has cell walls
pro cells eu plant cells and fungal cells
bacterial cell walls
made up of peptidoglycan
gram pos: thicker cell wall
gram neg: sandwitched btw two membranes
plant cell walls
cellulose
capsule/glycoalyx
jelly like coating of sugars and proteins
be used for protection or recognition/networking with other cells
glycocalyces
aid in protection from the environment as well as identifying certain cells
pilu
allow bacterial cells to hold on to surfaces or other bacteria
flagella
long extensions that have a cytoskeleton that are capable of producing movement
allows for swimming in an environment
common in bacteria but can be in eu cells
cellular reproduction
all cells are capable of reproducing themselves
mitosis
cell copies genetic material and then splits in two, dividing cellular contents
each daughter cell should be an approx copy of the parent cell
making macromolecules
all cells are capable of making macromolecules
where are proteins made
in ribosomes
prokaryotic cells
unicellular
smaller than eu cells
no membrane bound organelles and no compartmentalization
DNA gathered in center of cell
differences btw bacterial cells and eu cells
eu (animal) cells lack cell walls, so antibiotics that attack cell walls are safe for eukaryotic cells
ribosomes are molecularly different
eukaryotic cells can utilize sugars for energy much more efficiently than prokaryotic cells
eu cells
animal and plant cells
true nucleus
many organelles
differentiation
moment when a stem cell or zygote develops into different types of cells that do various tasks
distinction in size, shape, function, products they make, organelles, capabilities
nucleus
stores the genetic info as threads of chromatin
surrounded by its own membrane
during cell division chromatin condenses into
chromosomes
nucleolus
a dark structure in the center of the nucleus that contributes to ribosome production
Endoplasmic reticulum
system of membranous sacks
lipids and proteins made here
materials made leave in vesicles
vesicles
membrane bound sacs
Rough ER
protein production (studded with ribosomes)
ribosomes make the proteins–> proteins are then put into the Rough ER
Smooth ER
synthesis of lipids
carbohydrate synthesis (glycogen)
metabolism of carbohydrates
detox of drugs and alc
storage of calcium ions in some cells
golgi apparatus
processes molecules for secretion
modifies molecules then send them in vesicles to the plasma membrane
molecule is released by exocytosis
lysosomes
garbage disposals of the cell
surrounded by membrane
acidic interior
digests unwanted material taken in from outside ie bacteria , old cell parts
autophagy
cells use lysosomes to breakdown macromolecules into monomers for reuse
peroxisomes
contain enzymes that remove H and add to O2 producing H2O2 aka hydrogen peroxide
then convert H2O2 to H2O
used to digest some fatty acids, amino acids
vacuoles
big vesicles
storage (plants)
contractile vacuoles
contain water or air, expelled for propulsion-common in unicellular organisms
mitochondria
evolved from endosymbiosis
can reproduce itself
convert energy in consumed molecules into energy in the form of ATP
provide most of ATP for entire cell
cytoskeleton
network of fibers running throughout the cell
organelles attach to and move by the cytoskeleton
whole cell movement is accomplished by cytoskeleton
how cell shape is maintained
filaments
fibrous proteins supercoiled into thicker cables
maintains cell shape
anchors nucleus and other organelles
