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CH. 7
CELLULAR STRUCTURE AND
FUNCTION
• CELL DISCOVERY AND THEORY
• MAIN IDEA – The invention of the microscope led to
the discovery of __________________.
• HISTORY OF THE CELL THEORY
• Robert ____________ made a simple
microscope in 1665 and looked at a piece of
________________, the dead cells of oak
bark.
–Looked like cells that Monks lived in at a
monastery, giving us the term “________”
• ____________________ are the basic
structural and functional unit of all living
organisms.
• THE CELL THEORY
• Cell theory states:
– ____________ living organisms are composed
of one or more _________________.
– Cells are the ___________________________
of structure and organization of all living
organisms.
– Cells arise __________ from previously existing
cells, with cells passing _________________ of
their __________________ material on to their
daughter cells.
• BASIC CELL TYPES
• Cells __________________ based on the ________________
they perform for an organism
• Cells have one physical trait in common: they ____________
have a structure called a ______________________________
– Plasma membrane is a special boundary that helps
_______________ what _______________________ and
_____________ the cell.
• Cells have a number of functions in common.
– Most cells have genetic material to provide
_________________________ for making substances that
the cell _______________________.
– Cells also break down molecules to generate ___________
• Cells are groups into 2 categories:
– _________________________
– _________________________
• Generally are 1 to 100 times larger than prokaryotic
cells
• BASIC CELL TYPES – CONTINUED
• Both prokaryotic and eukaryotic cells have a plasma membrane
but category is decided on internal structures called
____________________________________
– Organelles are specialized structures that carry out
_____________ cell ___________________________.
• Eukaryotic cells contain:
– _______________________________________
• Is a distinct central organelles that contains the cell’s
genetic material in the form of __________________.
– __________________________ are membrane-bound.
• Organelles help cell functions to take place in
___________________ parts of the cell at the same time.
• Most eukaryotes are multicellular organisms, some are
unicellular like algae and yeast.
• BASIC CELL TYPES – CONTINUED
• Prokaryotic cells contain:
– ________________________________
– ___________ membrane bound organelles
– ____________________________ than eukaryotic cells
• Prokaryotes are unicellular organisms like ______________
• ORIGIN OF CELL DIVERSITY
• Scientists still investigating on how the 2 basic types of cells
originated.
– Endosymbiont theory says that that eukaryotic cells
evolved from prokaryotic cells, when one prokaryotic
cell began living _______________________ of another
prokaryotic cell and ____________________ received a
benefit from the relationship.
• SECTION 6.2 – THE PLASMA MEMBRANE
• MAIN IDEA – The plasma membrane helps to
maintain a cell’s _______________________
• QUESTION: What kind of substances do you
think go in & out of cells?
• FUNCTION OF THE PLASMA MEMBRANE
• Homeostasis is the process of maintaining
_____________ in an organism’s internal environment.
– Essential to the _____________________ of the cell
– Plasma membrane is primarily responsible for
helping to maintain homeostasis
• Plasma membrane is a thin, flexible ________________
__________________ boundary between a cell and its
environment that allows _______________ into the cell
and allows __________________ and other products
to leave the cell.
– Both prokaryotic & eukaryotic organisms have them
to separate them from the watery environments that
they exist in.
– _________________ how, when & how much of the
substances can enter & leave a cell, pg. 187, Figure 5
• STRUCTURE OF THE PLASMA MEMBRANE
• Most of the molecules in the plasma membrane are
______________________ (large molecules
composed of glycerol & 3 fatty acids)
– Phospholipid is formed when a phosphate group
replaces a fatty acid
• Plasma membrane is composed of a
______________________________________.
– 2 layers of phospholipids are arrange _______
_____________________
• Arranged in this manner to allow the plasma
membrane to exist in the water environment.
• THE PHOSPHOLIPID BILAYER
• Phospholipid is shown as a head with 2 tails.
– Phosphate group in each phospholipid makes the
head polar
• Attracted to water because water is also
________________
– 2 fatty acid tails are nonpolar and are repelled by
water
• Water soluble substances will ________ move easily
through the plasma membrane because they are
stopped by the nonpolar middle.
– Keeps the environment inside the cell
_________________ from the outside of the cell
• OTHER COMPONENTS OF THE PLASMA MEMBRANE
• Moving with & among the phospholipids in the plasma
membrane are ________________, __________________, and
__________________________________.
– Proteins on the outer surface of the plasma membrane are
called receptors and help transmit _____________________
to the inside of the cell
– Proteins at the inner surface ________________ the plasma
membrane to the cell’s internal _______________________
structure, helping the cell keep its ___________________
– Other proteins are spread throughout the entire membrane
and create ______________________ through which certain
substances ________________ & _______________ the cell
• Transport proteins move needed substances or waste
materials through the plasma membrane and contribute
to the selective permeability of the plasma membrane
• OTHER COMPONENTS OF THE PLASMA MEMBRANE –
CONTINUED
• Nonpolar cholesterol molecules are repelled by water
and are positioned among the phospholipids.
– Help to prevent the fatty-acid tails of the
phospholipid bilayer from _____________________
contributing to the ____________ movement in the
plasma membrane
– Cholesterol helps in maintaining ________________
in a cell.
• Carbohydrates attach to proteins and stick out from the
plasma membrane to define the cell’s characteristics
and help cells ____________________ chemical signals
– Ex: carbohydrates in the membrane might help
_______________________________cells recognize
and attack a potentially harmful cell.
• OTHER COMPONENTS OF THE PLASMA
MEMBRANE – CONTINUED
• Fluid mosaic model allows the
phospholipids to ____________ sideways
within the membrane, while at the same
time the other components like proteins
move among the phospholipids.
–Plasma membrane is in _____________
motion.
• Plasma membrane
• SECTION 7.3 – STRUCTURES AND
ORGANELLES
• MAIN IDEA – Eukaryotic cells contain
organelles that allow the ________________
and the ____________________ of functions
within the cell.
• QUESTION: Look at your tennis shoe and I
want you to identify all the different parts of
the shoe.
• CYTOPLASM AND ORGANELLES
• The environment ________________ the
plasma membrane or cell membrane is a
semifluid material called _____________.
–____________________ organisms all
chemical _________________ of the
cell takes place in the ______________
–_______________ organisms chemical
processes takes place in ____________
located within the ________________
• CYTOPLASM AND CYTOSKELETON CONTINUED
• Cytoskeleton is a supporting network of long, thin protein fibers
that form a framework for the cell and provide an ___________
for the ______________________________ inside the cells.
• Cytoskeleton also helps in cell ___________________ and other
cellular activities
• Cytoskeleton made up of substructures called:
– ___________________________________________
• Appear like long, _________________________________
cylinders that form a rigid skeleton for the cell and assist
in moving substances ______________________ the cell
– ________________________________________________
• Appear like thin __________________________ that help
give the cell shape and enable the entire cell or parts of
the cell to __________________________________
• Both microtubules and microfilaments rapidly ______________
and __________________________ and slide past one another
allowing cells and organelles to move
• CELL STRUCTURES
• In eukaryotic cells membrane-bound
organelles let _________________________
chemical processes to take place at the same
time in different parts of the cytoplasm.
• Each organelle has a ____________________
structure and function.
• NUCLEUS
• The _________________________ of the cell
__________________ what goes on in the cell
• Nucleus contains the cell’s _________, which
stores the __________ used to make proteins
for cell growth, function, and reproduction.
• Nucleus surrounded by a double membrane
called the ____________________________.
–Similar to plasma membrane but has
__________ to allow substances to move
______ & _______ of the nucleus.
• RIBOSOMES
• __________________ is the organelle that helps in the
manufacture of _____________________________.
• Ribosomes are made of 2 components:
– ______________________
– ______________________
• Ribosome production ___________ in the nucleus in an
area called the ________________________
• Some ribosomes float freely in the ________________
– Produce proteins for use within the cytoplasm of the cell.
• Some ribosomes are ___________________ to another
organelle called the ____________________________.
– Produce proteins that will be bound within
membranes or used by other cells
• ENDOPLASMIC RETICULUM (ER)
• Endoplasmic reticulum is a membrane system of folded
sacs & interconnected channels that serves as the site for
protein and lipid synthesis
• 2 types of endoplasmic reticulum (ER)
– ____________________________
• Has _______________________ attached
–Produce proteins for _____________ to other cells
– ________________________________
• Produces complex _________________________ &
____________________, including phospholipids, on
the membranes surface
• Smooth ER in the liver _________________________
harmful substances
• GOLGI APPARATUS
• _______________________________ is a flattened
stack of membranes that _______________,
_____________, and ______________________
proteins into sacs called ____________________.
• Golgi apparatus receives proteins from the
endoplasmic reticulum to be __________________
and sent out of the cell
– Vesicles can fuse with the cell’s plasma membrane to
___________________ proteins to the environment
outside of the cell.
• VACUOLES
• _________________ are membrane bound vesicles
that temporarily _________________ materials and
________________ products within the cytoplasm.
• In __________ cells vacuole are used to store food,
enzymes and other materials needed by a cell, and
some vacuoles store the waste products.
• In ______________ cells usually vacuoles are not
present, but if they have a vacuole they are much
_____________________ than those in plant cells.
• LYSOSOMES
• _______________________ are vesicles that
contain substances that _________________:
– excess or ___________________organelles
– _________________ particles
– _______________ and viruses
– Can fuse with vacuoles & send their enzymes into
the vacuoles to
____________________________
• Membrane around the lysosomes
________________ the digestive enzymes inside
from _______________________________ the cell
• CENTRIOLES
• ______________________ are organelles
made up of ________________________
that function during ________________.
• Centrioles are located in the
__________________ of animal cells and
most protists and are usually located near
the _________________.
• MITOCHONDRIA
• Mitrochondria ___________________ fuel particles
(mainly sugars) into usable energy.
– Referred to as the “_________________” of cells
• ________________ has an outer membrane and a
highly folded inner membrane that provides a large
surface area for breaking bonds of sugar molecules.
– Energy produced from breaking bonds is
_____________ in bonds of other molecules and
later used by the cell.
• CHLOROPLASTS
• Chloroplasts capture _______________ energy and
convert it to _________________ energy through a
process called ______________________________
– Chloroplasts are in ______________________ and some
eukaryotic cells.
– Light captured in thylakoids
– Pigment used is ______________________________
• CELL WALL
• Cell ____________ is in plant cells and is a thick, rigid,
mesh of fibers that surround the __________________ of
the plasma membrane and will protect the cell and give it
support.
– Cell wall made of _____________________
(carbohydrate)
• CILIA AND FLAGELLA
• Cilia are short, numerous projections that look like _______
extending from the surface of the cell
– Motion of cilia similar to the motion of rowing a rowboat
• Flagella are longer and less numerous than cilia.
– Motion are whiplike
• Both cilia and flagella are composed of ________________
• SECTION 6.4 – CELLULAR TRANSPORT
• MAIN IDEA – Cellular transport
_______________ substances
__________________ the cell and moves
substances _________ and __________
of the cell.
• QUESTION: How can you tell when
breakfast is cooking in the morning?
• How did these smells reach your nose?
• DIFFUSION
• ______________________ is the net movement of
particles from an area where there are __________
particles of the substance to an area where there are
_________________ particles of the substance.
• ___________________________ is the amount of a
substance in a particular area
– Substances diffuse from areas of _____________
concentration to areas of _______ concentration
• __________ energy is required for diffusion
– Particles already in motion
• 3 factors affect rate of diffusion:
– _________________________________
– _________________________________
– _________________________________
• DIFFUSION ACROSS THE PLASMA MEMBRANE
• Water can diffuse across plasma membrane,
but most other substances cannot
• __________________________uses transport
proteins to move other ions and small
molecules __________ the plasma membrane
–Particles are moving from areas of _______
concentration to areas of ______________
concentration
–__________ energy required
–Also called _________ transport
• OSMOSIS: DIFFUSION OF WATER
• _________________ is the diffusion of ________________
across a selectively permeable membrane
– Regulating the movement of water across the plasma
membrane is important in maintaining homeostasis
within the cell
• Concentration is the measure of the amount of solute
dissolved in a solvent
• Water molecules will diffuse _________________ the side
with the ___________________________ concentration of
____________________
• CELLS IN AN ISOTONIC SOLUTION
• Isotonic solution is when a cell has the ______
concentration of ____________________ and
_______________ (ions, sugars, proteins, and
other substances) as its cytoplasm.
–“Iso” means equal
–Water will ______________________ move
across the plasma membrane, but at the
___________________________________
–Most cells are in isotonic solutions
• Ex: _____________
• CELLS IN A HYPOTONIC SOLUTION
• _____________________ solution is when the cell is in a solution
that has a _________________ concentration of
_______________________________
– Hypo means under
– Water will move __________ the cell causing the cell to
___________________
– If too much water moves into the cell the cell can ____________
• CELLS IN A HYPERTONIC SOLUTION
• _____________________________ solution is when the
concentration of the _____________________ outside of the cell is
______________ than it is inside the cell.
– Hyper means above
– Water will flow _________________ of the cell causing the cell to
________________________
• PICTURE OF ISOTONIC, HYPOTONIC, AND
HYPERTONIC SOLUTIONS
• ACTIVE TRANSPORT
• __________________________________ is when
substances are moving from a region of
__________________ concentration to a region of
_____________________________ concentration
– Going ________________ the concentration gradient so
it ___________________________________________
– Proteins called ______________________ in the plasma
membrane move the substances
– Active transport helps maintain homeostasis
• TRANSPORT OF LARGE PARTICLES
• When substances are too large to move across the plasma
membrane or by a transport protein, they are moved by:
– __________________________________________
• Process where a cell ________________________ a
substance in a portion of the plasma membrane
• Membrane then __________________________ and
leaves the substance ____________________ the cell
– _________________________________________
• Process of secreting material from the cell
• Reverse process of endocytosis
• Used to ________________ and to secrete hormones
• Endocytosis & exocytosis ___________________________
• PICTURE OF ENDOCYTOSIS & EXOCYTOSIS