CellsCellsBy: Lorraine AmoahBy: Lorraine Amoah

[Adopted from James Holden & Clint Tucker][Adopted from James Holden & Clint Tucker]

The Cell TheoryThe Cell Theory In 1855, a number of scientists put In 1855, a number of scientists put

together a theory about cells…together a theory about cells…

1)1) All living things are composed of All living things are composed of Cells.Cells.

2)2) Cells are the basic unit of structure Cells are the basic unit of structure and function in living things.and function in living things.

3)3) New cells are produced from existing New cells are produced from existing cells.cells.

Who were these scientists?Who were these scientists?

Anton van LeeuwenhoekAnton van Leeuwenhoek Dutch businessman Dutch businessman

One of the first people to One of the first people to use a use a simple microscopesimple microscope to study nature.to study nature.

16741674 - - observed living observed living things in pond waterthings in pond water and and made detailed drawings made detailed drawings of each kind of of each kind of organismorganism. .

He called these He called these organisms organisms animalculesanimalcules..

Robert HookeRobert Hooke English physicist English physicist

16651665 - - used one of the used one of the first first light microscopeslight microscopes to to look at thin slices of look at thin slices of plant plant tissuestissues a slice of a slice of CORKCORK

CalledCalled thousands of tiny thousands of tiny chamberschambers “ “cellscells,”,” because they reminded because they reminded him of a monastery’s tiny him of a monastery’s tiny rooms.rooms.

this discovery motivated this discovery motivated scientists to search for scientists to search for cells in other living cells in other living things. things.

The Final ThreeThe Final Three

18381838 – – Mathias SchliedenMathias Schlieden found that found that all Plants are made of all Plants are made of cells.cells. 18391839 – – Theodore SchwannTheodore Schwann found that found that Animals are also made Animals are also made up of cellsup of cells

18551855 – – Rudolf VirchowRudolf Virchow found that found that “Where a cell exists, there “Where a cell exists, there must have been a preexisting cell.…” must have been a preexisting cell.…” oror cells come from cells cells come from cells

Basic Cell StructuresBasic Cell Structures Cell MembraneCell Membrane – thin, flexible semi – thin, flexible semi

permeable membrane around the cell; permeable membrane around the cell; monitors what enters and exits the cellmonitors what enters and exits the cell

Nucleus-Nucleus- a large structure that a large structure that contains the cell’s genetic material and contains the cell’s genetic material and controls the cell’s activities controls the cell’s activities

Cytoplasm-Cytoplasm- material inside the cell material inside the cell membrane—but not including the membrane—but not including the nucleusnucleus The semi-fluid substance that fills the The semi-fluid substance that fills the

cytoplasm is called the cytoplasm is called the cytosolcytosol

Test your knowledge…Test your knowledge…

On your study notes, Label these three parts below

And the Answer is…And the Answer is…

Cell Membrane

Cytoplasm

Nucleus

Prokaryote vs. EukaryoteProkaryote vs. Eukaryote

ProkaryoteProkaryote - have cell membranes and - have cell membranes and cytoplasm but cytoplasm but do not contain nucleido not contain nuclei. . Simple CellsSimple Cells All All bacteriabacteria are prokaryotes. are prokaryotes.

Eukaryote-Eukaryote- Contain Contain nucleinuclei. Also have a cell . Also have a cell membrane, cytoplasm, and membrane, cytoplasm, and specialized specialized organellesorganelles.. Complex CellsComplex Cells All All plantsplants, , animalsanimals, , fungifungi, and many , and many

microorganisms, are eukaryotes.microorganisms, are eukaryotes. Eukaryote cells are much larger than prokaryote Eukaryote cells are much larger than prokaryote

cellscells

Test Your Knowledge…Test Your Knowledge…Fill in this Venn Diagram using the pictures of prokaryotes/eukaryotes & your Notes

Prokaryote

Eukaryote

And the And the Answer is…Answer is…

Prokaryote

Eukaryote

• No nucleus• Simple Cells

•Cell Membrane•Cytoplasm

• Nucleus• Complex Cells• Specialized Organelles

Cell Structure & Cell Structure & OrganellesOrganelles

Organelles-Organelles- specialized specialized structure that performs structure that performs

important cellular functions important cellular functions within a eukaryotic cellwithin a eukaryotic cell

Cell StructureCell Structure Cell WallsCell Walls provide extra support provide extra support

and protectionand protection Plants, bacteria, algae, and fungi Plants, bacteria, algae, and fungi

have have Cell WallsCell Walls* In plants, cell walls are * In plants, cell walls are

composed composed of cellulose of cellulose

* Animal Cells * Animal Cells

DO NOTDO NOT

havehave

CELL WALLSCELL WALLS

CytoskeletonCytoskeleton Network of protein filaments that Network of protein filaments that

helps the cell helps the cell maintain shapemaintain shape and is and is involved in involved in cell movement.cell movement. Contains Contains 2 parts:2 parts:

MicrofilamentsMicrofilaments – – long, thin strandslong, thin strands

that help a cell move and provide athat help a cell move and provide a

tough framework for the celltough framework for the cell

MicrotubulesMicrotubules – – hollow tubes hollow tubes

by which organelles can move from by which organelles can move from

one part of a cell to anotherone part of a cell to another

NucleusNucleus Stores hereditary info in the form of Stores hereditary info in the form of

DNA DNA DNA is inside DNA is inside chromatinchromatin, a granular , a granular

material that condenses into material that condenses into chromosomeschromosomes during cell divisionduring cell division

Houses a Houses a nucleolusnucleolus – small, dense – small, dense region within responsible for the region within responsible for the assembly of ribosomesassembly of ribosomes

Surrounded by a Surrounded by a nuclear envelopenuclear envelope

““The Control Center”The Control Center”

The NucleusThe Nucleus

CentriolesCentrioles ttiny structures located in the iny structures located in the

cytoplasm of cytoplasm of animal cellsanimal cells near near the nuclear envelope.the nuclear envelope.

Play a role in cell division.Play a role in cell division.

RibosomesRibosomes

Make proteinsMake proteins

Made up of rRNA (ribosomal RNA) Made up of rRNA (ribosomal RNA) and proteinand protein

Can be free-roaming in cytoplasm or Can be free-roaming in cytoplasm or located on the Rough Endoplasmic located on the Rough Endoplasmic ReticulumReticulum

Endoplasmic ReticulumEndoplasmic Reticulum Organelle where components of cell Organelle where components of cell

membrane are made and proteins are membrane are made and proteins are modifiedmodified

Rough E.RRough E.R.. studded with ribosomesstudded with ribosomes Either exports proteins from cell or sends Either exports proteins from cell or sends

them to the cytoplasmthem to the cytoplasm

Smooth E.RSmooth E.R.. No ribosomesNo ribosomes Helps in lipid production and breakdown of Helps in lipid production and breakdown of

toxic substancestoxic substances

The Endoplasmic Reticulum The Endoplasmic Reticulum (E.R.)(E.R.)

Golgi ApparatusGolgi Apparatus Vesicles (Vesicles (small transport sacssmall transport sacs) carry ) carry

proteins from Rough E.R. to Golgi for proteins from Rough E.R. to Golgi for processing/modificationprocessing/modification..

Attaches carbohydrates and lipids to Attaches carbohydrates and lipids to proteins, and the new proteins are proteins, and the new proteins are “packaged” in new vesicles.“packaged” in new vesicles.

LysosomesLysosomes

Small organelles Small organelles filled with digestive filled with digestive enzymesenzymes They can break down They can break down

needed materials, needed materials, used cell parts, used cell parts, pathogens, and even pathogens, and even play a role in play a role in developmentdevelopment

They destroy tissue to They destroy tissue to create fingers because create fingers because our hands begin as our hands begin as solid structures! solid structures! Lysosome Animation

Who am I?Who am I?

cell organelle that cell organelle that stores materials stores materials such as water, such as water, salts, proteins, and salts, proteins, and carbohydratescarbohydrates

Vacuole

ChloroplastsChloroplasts

Found in plants, some algae, and some Found in plants, some algae, and some bacteriabacteria

Converts the sun’s light energy into chemical Converts the sun’s light energy into chemical energy during energy during photosynthesisphotosynthesis

Contains Contains chlorophyllchlorophyll ( (greengreen pigment) pigment)

MitochondriaMitochondria

cell organelle that releases cell organelle that releases energyenergy from stored food from stored food molecules. molecules.

Involved in Involved in cellular respiration-cellular respiration- turning turning carbohydrates into energy.carbohydrates into energy.

Cells that need more energy have more Cells that need more energy have more mitochondriamitochondria

Other Cell StructuresOther Cell Structures

CiliaCilia (cilium): (cilium): short hair-like short hair-like projection; projection; produces produces movement in movement in many cellsmany cells

FlagellaFlagella (flagellum): whip-(flagellum): whip-like structure on like structure on some cells that is some cells that is used for movementused for movement

Cilia Flagella

Factory Part

Function Organelle

Central Office Manages activities, initiates production, controls activities of factory

1

Assembly Line Assembles raw materials to manufacture items 2

Packaging & Shipping

Packs products for distribution 3

Conveyer Belt Moves product within the factory 4

Generator Produces energy for the factory 5

Storage area Stores materials for later use 6

Collection center Breaks down and recycles used parts 7

Door Allows for things to enter and leave the factory 8

Bricks and Steel Construction materials that keep the factory from collapsing

9

Trucks/ 18 Wheelers

Move the factory when it needs to relocate 10

Example II: The Cell Example II: The Cell FactoryFactory

Factory Part

Function Organelle

Central Office Manages activities, initiates production, controls activities of factory

Nucleus

Assembly Line Assembles raw materials to manufacture items Ribosome

Packaging & Shipping

Packs products for distribution Golgi Bodies

Conveyer Belt Moves product within the factory Endoplasmic reticulum

Generator Produces energy for the factory Mitochondrion

Storage area Stores materials for later use Vacuole

Collection center Breaks down and recycles used parts Lysosome

Door Allows for things to enter and leave the factory Cell membrane

Bricks and Steel Construction materials that keep the factory from collapsing

cytoskeleton

Trucks/ 18 Wheelers

Move the factory when it needs to relocate centrioles

Answers: The Cell Answers: The Cell FactoryFactory

So Where did these So Where did these Eukaryotes come from?Eukaryotes come from?

Mitochondria and Chloroplasts Mitochondria and Chloroplasts contain their own DNA genetic contain their own DNA genetic information separate from the cells information separate from the cells DNA.DNA.

So, Scientists have done research and So, Scientists have done research and come up with a come up with a TheoryTheory……

The The ENDOSYMBIONT THEORYENDOSYMBIONT THEORY

Let’s take a look at this evolution…

The Endosymbiont The Endosymbiont TheoryTheory

The first eukaryotes may have The first eukaryotes may have formed from one bacteria engulfing formed from one bacteria engulfing another without killing it.another without killing it.

Later a symbiotic relationship was Later a symbiotic relationship was formedformed

Plant CellsPlant Cells Cell wallCell wall located outside the cell membrane. located outside the cell membrane.

Cell wall is made from cellulose fibers, and it Cell wall is made from cellulose fibers, and it is used for support & protectionis used for support & protection

Contains one large Contains one large vacuolevacuole that contains that contains water. Vacuole full = plant is rigid. Vacuole water. Vacuole full = plant is rigid. Vacuole loses water = plant wiltsloses water = plant wilts

ChloroplastsChloroplasts = contain chlorophyll, which = contain chlorophyll, which captures sunlight & converts it into energycaptures sunlight & converts it into energy

Plant CellPlant Cell

Build a plant cell

Animal CellsAnimal Cells

Have no cell wallHave no cell wall

NO chlorophyllNO chlorophyll

CANNOT make CANNOT make their own foodtheir own food

So Plant and So Plant and Animal Cells Animal Cells

are…are…

Both eukaryotic cells- Both have nucleuses, organelles, cell membranes, cytoplasm

Plant and animal cell differences

Plant CellsPlant Cells Cell wallCell wall ChloroplastsChloroplasts Large central Large central

vacuolevacuole No centriolesNo centrioles

Animal CellsAnimal Cells Have Have

centriolescentrioles No cell wallNo cell wall No No

chloroplastschloroplasts No large No large

central central vacuolevacuole

Construct a cell

Diversity of LifeDiversity of Life

Unicellular organisms-Unicellular organisms- A single- A single-celled organism celled organism

Unicellular organisms Unicellular organisms include both include both prokaryotes and eukaryotesprokaryotes and eukaryotes. .

A prokaryotic unicellular organismA eukaryotic unicellular organism (paramecium)

Contractile Vacuole

Multicellular Multicellular organisms-organisms- organisms that have organisms that have more than one cell more than one cell working together. working together. Have cell Have cell specializationspecialization

Cell specialization-Cell specialization- specific roles for specific roles for different types of different types of cellscells

Diversity of Life Diversity of Life Continued…Continued…

Levels of OrganizationLevels of Organization

Cells-Cells- the basic unit of life the basic unit of life Tissues-Tissues- a group of similar cells that a group of similar cells that

perform a particular function perform a particular function Organs-Organs- many groups of tissues work many groups of tissues work

together together Organ Systems-Organ Systems- A group of organs that A group of organs that

work together to perform a specific work together to perform a specific function function

Organism-Organism- An entire living being made up An entire living being made up of organ systemsof organ systems

Test your Knowledge…Test your Knowledge…

Using the following terms, place the levels of organizationin the correct order of the chart.

-Stomach - Digestive System-Smooth muscle tissue -Muscle Cell

? ? ? ?

And the Answer is…And the Answer is…