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