Also, how substances

are transported

throughout the cell.

Why Study Cells? Cells are as fundamental to Biology as the atom is to

chemistry.

All organisms are made of cells.

The cell is the simplest collection of living matter that can live.

Everything an organism does occurs fundamentally at the cellular level

The Order of Things: Organism

Organ system

Organs

Tissue

Cells

Organelles Macromole

cules

atoms

Cells are about 90% water, the rest (other 10%) is about…

50% protein

15% carbohydrate

15% nucleic acid

10% lipid

10% other

Contributors to the Cell Theory

Anton Van Leeuwenhoek developed

the first microscope (observed organisms in pond water)

Robert Hooke discovered the cell in 1655

(looked at wood, stems, & thought that

compartments looked like cells

in a monastery—(small rooms)

Cork Cells

Other Contributors

Robert Brown 1833 observed that many cells have dark structure near the center— now known to be the nucleus.

Mathias Schleiden stated that all plants are made of cells

Theodore Schawn Stated that animals are made up of cells

Rudolf Virchow stated that all cells come from pre existing cells

The Three Parts of the Cell Theory

1-All living things are made of cells

2-Cells are the basic units of structure and function in living thing

3-All cells come from preexisting cells

All cells can be classified as Prokaryotes (no true nucleus)

(Think pro=NO)

All cells can be classified as

Eukaryotes ( has True nucleus)

(Think Eu (you)=TRUE)

Prokaryotic Cells

Has No true nucleus

NO membrane bound

organelles

Have a simple structure and are

smaller in size. Mostly Unicellular (1 cell)

All are Bacteria Eubacteria &

Archeabacteria

Eukaryotic Cells

Has a true Nucleus

Has Membrane bound

Organelles

Are more complex and are larger in

size

Protists, Fungi, Plants, and Animals are all

eukaryotes

Prokaryotic Cells Locomotion Some use flagella

Some use a slime layer

Some don’t move at all

Click on the link below and

read about 5 fun facts about

bacteria (prokaryotes)

BACTERIA FUN FACTS

Bacterial cell wall

Flagellum

Rotary motor

Sheath

How did cells change,

make the transition from

prokaryotic (NO nucleus)

to eukaryotic (TRUE

nucleus) cells?

Endosymbiotic Theory

Endosymbiotic theory suggests that eukaryotes

arose from a symbiotic relationship between

various prokaryotes.

Heterotrophic bacteria became mitochondria.

Cyanobacteria (autotrophic bacteria) became

chloroplasts.

Host cell was a larger prokaryotic cell.

Evidence for this theory is that mitochondria,

centrioles and chloroplasts have their OWN

DNA

Endosymbiosis

Smaller

Prokaryotic

cell

Host cell

Prokaryotic

cell is

engulfed

Symbiosis-Increases

survival of both! CLICK for More on

endosymbiosis

Eukaryotes Eukaryotes arose from

prokaryotes and developed into larger more complex organisms.

Eukaryotes are cells that contain a nucleus and organelles surrounded by a membrane, such as the ER, mitochondria and chloroplasts.

The Nucleus

All eukaryotic cells have a nucleus at some point. This is a membrane-bound structure that contains the DNA (organism's genome). The nuclear membrane has pores or holes in it.

The nucleolus is also in the nucleus where ribosome units are made.

Cytoplasm The cytoplasm is the

AREA between the

nucleus and the cell

membrane.

(the cytosol is the jelly-

like substance filling

the space)

Many chemical

reactions occur here.

Cell membrane Structure & Function

Separates cells from their

environment

Controls what goes in & out of cells

Aids in the protection & support of the cells

Aids in inter cell communication (BETWEEN cells)

Cell membrane Structure & Function

Separates cells from their environment

Controls what goes in & out of cells

Aids in the protection & support of the cells

Aids in inter cell communication (BETWEEN cells)

Cell Membrane Structure & Function Mostly phospholipid bi-layer with the outer part being hydrophilic (phosphate head) and the inner portion very hydrophobic (2 fatty acids)

The hydrophilic heads allow interaction with watery environment inside and out

The hydrophobic inner layers squeeze together and are both stable and fluid

Proteins either move freely w/in the layer & act as channels thru which molecules can OR act like a pump pushing molecules from one side of the membrane to another.

Carbohydrates are attached to proteins, and help cells recognize & interact w/ each other

Cell Wall Found in plants, algae, bacteria,& fungi

Lies OUTSIDE of the cell membrane

Helps protect & support the cell

In plants the primary cell wall is made up of cellulose, makes it elastic so that plant can grow.

In plants with woody stems, a secondary cell wall develops—made up of cellulose & lignin—which makes it rigid.

Ribosomes—Structure & function

Site of protein synthesis (place where proteins are made)

Cells that have high rates of protein synthesis—like the liver have a larger # Ribosomes.

Free Ribosomes are suspended in the Cytosol

Bound Ribosomes are attached to the rough ER.

More about Ribosomes

Made of TWO sub-units that are 60% protein and 40% ribosomal RNA

Free Ribosomes make different proteins than Bound ribosomes (on ER)

They can switch

places as needed

depending on

metabolic needs

of the cell

The endoplasmic reticulum (ER) is where lipids of the cell membrane, along with proteins and other materials are assembled.

Rough ER has ribosomes & Smooth ER has no ribosomes

The ER usually surrounds the nucleus and may reach the cell membrane

Function of the Smooth ER Functions in many different metabolic processes:

Makes Lipid (fats)

Including phospholipids & steroids

Detoxification (lots of smooth ER in liver cells)

Function of the Rough ER Ribosomes are attached to it

Major site of protein synthesis

Makes secretary proteins—

called glycoproteins because they are bound to

carbohydrates (glyco part)

It is also involved in membrane production

Click on link

THE MAKING OF A PROTEIN

Golgi apparatus

collection of Golgi bodies Stacked flattened

sacks Site where cell

products are packaged for export

Proteins are modified by being combined with fats or carbohydrates

Golgi apparatus

Vesicles then pinch off from the Golgi body to be secreted (outside the cell)

Involved in the production of lysosomes

Golgi apparatus

Has

Vesicles

Close to cell membrane

Golgi apparatus

Function of the Mitochondria Site of Cellular Respiration which Converts

Glucose molecules into ATP energy which the cell can use-

C6H12O6 + O2 H2O + CO2 + ATP (energy)

Membrane bound organelle

It is called the power house

of the cell because it is the

site of cell respiration.

Function of the Mitochondria Found in ONLY in ALL Eukaryotic cells &

has its own DNA (remember endosymbiosis)

Chloroplasts are

organelles that

capture sunlight

energy and convert

it into chemical

energy in a process

known as photosynthesis.

Sunlight + H2O + CO2 C6H12O6 + O2

Vacuoles

Found in PLANT and ANIMAL cells

The vacuole acts a container, storing water and dissolved particles

Plants have a large central vacuole for water storage and to maintain turgor pressure

Unicellular organisms can use contractile vacuoles for movement and to maintain homeostasis (water balance)

video

High

Turgor-

Full

vacuoles

Low

Turgor-

empty

vacuoles

Lysosomes

Are membrane bound sacs of

hydrolytic enzymes

Are used by the cell to digest

(lyse=breakdown)

Macromolecules-like proteins,

polysaccharides, fats, & nucleic acids.

If the cell releases too many Lysosomes it will die because it will eat itself (autolysis).

More about Lysosomes Involved in Phagocytosis—is when a large

molecule engulfs a smaller molecule.

Are often found in white blood cells, used as a immune—defense—mechanism to eat pathogens like viruses and bacteria.

Tay Sach’s, a fatal genetic disease—occurs when a lipid eating enzyme is missing so the fat accumulates in the cells preventing the brain from working.

The cytoskeleton is a network of protein filaments that helps the cell maintain its shape.

It is also involved in movement.

Centrioles Centrioles are

cylindrical bundles of microtubules that function during cell reproduction in animal cells.

Cilia and Flagella

Some eukaryotes have

cilia or flagella for

locomotion or as tissue

to help move stuff along.

Flagella are long whip-

like structures.

Cilia are more numerous

and are “short flagella”.

Eukaryotic differ from

prokaryotic cillia/ flagella

Plant vs. Animal Cells

PLANT

CELL

ANIMAL

CELL Cell membrane

Mitochondria

Golgi apparatus

Nucleus

Cytoskeleton

Ribosomes

Endoplasmic

reticulum

Lysosomes

HAVE:

Cell Wall

LARGE vacuoles

Chloroplasts

DO NOT HAVE:

Centrioles

HAVE:

Centrioles

DO NOT HAVE:

Cell Wall

LARGE vacuoles

Chloroplasts

Turn to page 8 of packet and click on link and complete sheet! When done return to the notes ;-)

cell part QUIZ!

The Cell Membrane As previously mentioned, The cell

membrane is the edge of life, the boundary that separates the living cell from its environment.

It’s almost like the bouncer in the club that is in charge of regulating who goes in and out of the party.

Selectively-Permeable Cell membranes are

always selectively-permeable,

meaning that some molecules

are allowed to pass freely

(diffuse) through the

membrane while others are not.

Made of a phospholipid bilayer,

Also called the “Fluid Mosaic Model”

Phospholipid bilayer or

phosphodigyceride

Head Polar (charged)

Phosphate (PO4)

Hydrophilic (water-loving)

Pointed toward inside & outside of cell

Tails (2) Nonpolar (no charge)

Fatty acid chains

Hydrophobic (water-hating)

Pointed toward middle of membrane

Permeability Vocabulary: Semi-permeable

• Some things can enter the while others can not

• Think of the Bouncer at the club that lets the pretty and the popular students in. But leaves the crazy science teachers outside staring at the door.

Complete Permeable

• Everything can enter the cell.

• An open door

Impermeable

• Nothing can enter the cell.

• Closed and locked door

Types of Transport

Passive Transport

Osmosis Diffusion Facilitated

Diffusion

Active Transport

Endocytosis & Exocytosis

Protein pumps

Types of Transport…diagram

Passive Transport

Requires No ATP

(energy)

Goes with (down)the

concentration gradient (from high-low concentration)

examples:

Osmosis, diffusion & facilitated

diffusion

Active Transport

Requires ATP energy

Goes against (up) the concentration

gradient (from low-high)

examples:

Endocystosis, exocytosis &

protein pumps.

Osmosis and Diffusion Diffusion- movement of materials from an area of high concentration to an area of low concentration.

In cells O2 and CO2 diffuses in and out Click on link

diffusion

Osmosis – diffusion of water which moves from a

high to low concentration. Click on link (be sure to add salt!)

osmosis

Dynamic Equilibrium

Particles move in and out at the same rate, so there is

no overall change and the cell remains in balance

Diffusion

Concentration gradient

The difference in

concentration of

molecules across

a distance in a

solution or in

and out of cells.

Hypertonic, Hypotonic, and Isotonic Solutions (The Power of Osmosis) The concentration of solute in the solution can be

less than the concentration of solute in the cells. The cell is in an hypotonic solution. (hypo = less than normal)

The concentration of solute in the solution can be greater than the concentration of solute in the cells. The cell is in an hypertonic solution. (hyper =

more than normal)

The concentration of solute in the solution can be equal to the concentration of solute in the cells. The cell is in an isotonic solution. (iso = same as normal)

Osmosis Hypotonic Solutions

• Solution has less solute (salt) than the cell

• Water enter the cell

• Cell swells

Hypertonic Solutions

• Solution has more solute than the cell

• Water leaves the cell.

• Cell shrinks

Isotonic solution

• Solute concentration of the solution is equal to that of the cell.

• No net movement of water

• Cell stays the same

Osmosis Diffusion of water through a selectively permeable

membrane.

From high water concentration to low water concentration

Click on link below and take the quiz

OSMOSIS

Osmosis- animal cells (RBC)

Osmosis- Plant cells

Facilitated Diffusion Movement of specific molecules across cell

membranes through protein channels or doorways from a high to low concentrations

Is fast and specific, but does not require cell energy.

Glucose

moves

through cell

membranes

this way

Active Transport A material moves from an area of lower

concentration to an area of higher concentration.

REQUIRES the input of cell energy.

THREE main types

1-Protein Pumps-cell membrane protein that “pumps” ions into cell, Na+ K+ pumps enable nerve impulses to move from cell to cell

click on link protein pump

more Active Transport 2-Endocytosis: the process of taking material into

the cell by means of pockets of the membrane.

TWO KINDS Phagocytosis: type of endocytosis where the

cytoplasm surrounds and engulfs large particles “cell eating”

Pinocytosis: “cell drinking”

3-Exocytosis: the removal of cell contents that consists of the membrane fusing with the membrane of the object and forcing the content out the cell. Exiting the cell “cell pooping”

Active Transport

(Requires energy)

Endocytosis “stuff coming into the cell against the gradient”

Phagocytosis

“cell eating”

Pinocytosis

“Cell drinking”

Exocytosis “Stuff leaving the cell

against the gradient

Opposite of endocytosis “getting

rid of waste”

Protein pumps Ex. Sodium-

Potasium pumps

Exocytosis

Phagocytosis

Protein Pump (Na+ K+)

Phagocytosis (taking place in cells under a microscope)

Review ALL Cell Transport Click on link below and review all the forms

of cell transport…have fun!

review! Ready for a quiz??????