February 1, 2011• Staple and turn in lab. PLEASE make sure pages are in

order and your name is on it.• Return graded work• Review/Questions• Test-Organic Chemistry• Lecture-Cell Structure• Lab-Cell Structure• Homework:

– Lab Review Questions– Cell Structure Review– Study for Test

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Basic Structure of a Cell

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Review Facts Review Facts About Living About Living

ThingsThings

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What Are the Main What Are the Main Characteristics of Characteristics of

organisms?organisms?1. Made of CELLS2. Require ENERGY (food)3. REPRODUCE (species)4. Maintain HOMEOSTASIS5. ORGANIZED6. RESPOND to environment7. GROW and DEVELOP8. EXCHANGE materials with

surroundings (water, wastes, gases)

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LEVELS OF ORGANIZATIONLEVELS OF ORGANIZATION

Nonliving Levels:1.ATOM (element)2.MOLECULE (compounds like

carbohydrates & proteins)3.ORGANELLES (nucleus, ER,

Golgi …)

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LEVELS OF ORGANIZATIONLEVELS OF ORGANIZATION

Living Levels:4.CELL (makes up ALL organisms) –

LIFE begins5.TISSUE (cells working together6.ORGAN (heart, brain, stomach …)7.ORGAN SYSTEMS (respiratory,

circulatory …)8.ORGANISM

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LEVELS OF ORGANIZATIONLEVELS OF ORGANIZATIONLiving Levels continued:9.POPULATION (one species in an area)10.COMMUNITY (several populations in

an area11.ECOSYSTEM (forest, prairie …)12.BIOME (Tundra, Tropical Rain

forest…)13.BIOSPHERE (all living and nonliving

things on Earth)

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History of Cells & the History of Cells & the Cell TheoryCell Theory

Cell Specialization

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First to View CellsFirst to View Cells•Robert Hooke -

microscope to examine a thin slice of cork

• looked like small boxes

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First to View CellsFirst to View Cells•Hooke -

responsible for naming cells

•“CELLS” – because small rooms that monks lived in called Cells

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Anton van Leeuwenhoek

• Leeuwenhoek (Dutch microscope maker), - first to view organisms

• used a simple, handheld microscope to view pond water & scrapings from his teeth

MICROSCOPESMICROSCOPES

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Microscopy and Microscopy and MeasurementMeasurement

• Microscopes – produce an produce an enlarged image of an objectenlarged image of an object– Used to study organisms, cells, and cell parts– Increase in apparent size is called

magnificationmagnification– The ability to show details clearly is called

resolutionresolution– Microscopes vary in both magnification and

resolution

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Compound Light Compound Light MicroscopesMicroscopes

• SpecimenSpecimen mounted on a glass slideglass slide

• Must be thinly sliced or very small

• Pair of lenseslenses– OcularOcular lens (eye piece)– ObjectiveObjective lens (nose

piece)• Can be used to study

LIVE specimensLIVE specimens

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• MagnificationMagnification determined by multiplying power of both lenses

• Eyepiece 10X times Objective power (20X, 40X…)

• HighestHighest Maximum magnification is around 1000X1000X

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Electron MicroscopeElectron Microscope• Transmission EM (TEM)Transmission EM (TEM)

– Uses a beam of electrons beam of electrons to produce an enlarged image of very thinly sliced specimen on screen or photographic plate

– Image focused by magnetic magnetic lenseslenses

– 200,000X magnification– Cannot be used to view living

specimens

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• Scanning EM (SEM)Scanning EM (SEM)– 3D3D image– Specimens not sliced for not sliced for

viewingviewing– Surface sprayed with fine Surface sprayed with fine

metal coatingmetal coating– Also uses electron beam and

fluorescent screen or photographic plates

– 100,000X magnification100,000X magnification– Cannot be used to view living Cannot be used to view living

specimensspecimens

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Beginning of the Cell Beginning of the Cell TheoryTheory

•Matthias Schleiden – botanist, concluded all plants were made of cells

•a cofounder of the cell theory

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Beginning of the Cell Beginning of the Cell TheoryTheory

•Theodore Schwann – zoologist, concluded all animals were made of cells

•also cofounded the cell theory

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Beginning of the Cell Beginning of the Cell TheoryTheory

• Rudolph Virchow – doctor, observed cells dividing under the microscope

• reasoned that all cells come from other pre-existing cells by cell division

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CELL THEORY

•All living things are made of cells

•Cells are the basic unit of structure and function in an organism (basic unit of life)

•Cells come from the reproduction of existing cells (cell division)

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Cell Size and TypesCell Size and Types

• Cells can only be observed under microscope

• Three Basic types:

Animal Cell Plant CellBacterial

Cell

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Number of CellsNumber of CellsOrganisms may be:• Unicellular – composed of one cell

• Multicellular- composed of many cells that may organize into tissues, etc.

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CELL SIZECELL SIZE

Typical cells range from 5 – 50 micrometers (microns) in diameter

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Which Cell Type is Which Cell Type is Larger?Larger?

_________ > _____________ > ___________Plant cell Animal cell bacteria

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How Big is a Micron ( µ ) ?How Big is a Micron ( µ ) ?

1 cm = 10,000 microns 1” = 25,000 microns

1 mm = 1000 microns

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Multicellular OrganismsMulticellular Organisms• Cells in multicellular organisms

often specialize (take on different shapes & functions)

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Cell SpecializationCell Specialization

•Specialization - turning different genes on and off

•DIFFERENTIATION

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Specialized Animal CellsMuscle cells Red blood cells

Cheek cells

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Specialized Plant cells

Xylem cellsPollen

Guard Cells

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Organization Organization Levels of LifeLevels of Life

Atoms to OrganismsAtoms to Organisms

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ATOMS MOLECULES ORGANELLES

Nonliving LevelsNonliving Levels

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CELLS – life starts here

TISSUES – Similar cells working together

Living LevelsLiving Levels

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ORGANSORGAN SYSTEMS ORGANISM

Different tissuesworking together

Different organsworking together

More Living LevelsMore Living Levels

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Simple or Complex Simple or Complex CellsCells

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Prokaryotes – The first Prokaryotes – The first CellsCells

• Cells that lack a nucleus or membrane-bound organelles

• Includes bacteria• Simplest type of cell• Single, circular chromosome

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ProkaryotesProkaryotes

• Nucleoid region (center) contains the DNA

• Surrounded by cell membrane & cell wall (peptidoglycan)

• Contain ribosomes (no membrane) in their cytoplasm to make proteins

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Eukaryotes

• Cells that HAVE a nucleus and membrane-bound organelles

• Includes protists, fungi, plants, and animals

• More complex type of cells

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Eukaryotic Cell

Contain 3 basic cell structures:

•Nucleus•Cell Membrane•Cytoplasm with

organelles

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Two Main Types of Eukaryotic Cells

Plant Cell

Animal Cell

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OrganellesOrganelles

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OrganellesOrganelles

•Very small (Microscopic)•Perform various functions for

a cell•Found in the cytoplasm•May or may not be

membrane-bound

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Animal Cell OrganellesAnimal Cell Organelles

NucleolusNucleus

Nuclear envelope

Ribosome (attached)Ribosome (free)

Cell Membrane

Rough endoplasmic reticulum

Golgi apparatus

Mitochondrion

Smooth endoplasmicreticulum

Centrioles

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Plant Cell OrganellesPlant Cell Organelles

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Cell or Plasma MembraneCell or Plasma Membrane

Outsideof cell

Insideof cell(cytoplasm)

Cellmembrane

Proteins

Proteinchannel Lipid bilayer

Carbohydratechains

• Composed of double layer of phospholipids and proteins

• Surrounds outside of ALL cells• Controls what enters or leaves the cell• Living layer

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•Lies immediately against the cell wall in plant cells

•Pushes out against the cell wall to maintain cell shape

Cell Membrane in PlantsCell Membrane in PlantsCell membrane

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•Nonliving layer•Found in plants, fungi, & bacteria

•Made of cellulose in plants

•Made of peptidoglycan in bacteria

•Made of chitin in Fungi

Cell wallCell WallCell Wall

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Cell WallCell Wall• Supports and

protects cell• Found outside of

the cell membrane

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•Jelly-like substance enclosed by cell membrane

•Provides a medium for chemical reactions to take place

Cytoplasm of a Cytoplasm of a Cell Cell

cytoplasm

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•Contains organelles to carry out specific jobs

•Found in ALL cells

More on CytoplasmMore on Cytoplasmcytoplasm

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•Controls the normal activities of the cell

•Contains the DNA in chromosomes

•Bounded by a nuclear envelope (membrane) with pores

•Usually the largest organelle

The Control Organelle - The Control Organelle - NucleusNucleus

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Nuclear EnvelopeNuclear Envelope

• Double membrane surrounding nucleus

• Also called nuclear membrane

• Contains nuclear pores for materials to enter & leave nucleus

• Connected to the rough ER Nuclear

pores

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Nucleolus

• Inside nucleusInside nucleus• Cell may have Cell may have 1 1

to 3to 3 nucleoli nucleoli• DisappearsDisappears

when cell when cell dividesdivides

• Makes Makes ribosomesribosomes that that make proteinsmake proteins

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CytoskeletonCytoskeleton• Helps cell maintain

cell shape• Also help move

organelles around• Made of proteins• Microfilaments are

threadlike & made of ACTIN

• Microtubules are tubelike & made of TUBULIN

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CytoskeletonCytoskeleton

MICROTUBULES

MICROFILAMENTS

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CentriolesCentrioles• Found only in animal

cells• Paired structures

near nucleus• Made of bundle of

microtubules• Appear during cell

division forming mitotic spindle

• Help to pull chromosome pairs apart to opposite ends of the cell

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Centrioles & the Mitotic Centrioles & the Mitotic SpindleSpindle

Made of MICROTUBULES (Tubulin)

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MitochondrionMitochondrion(plural = mitochondria)(plural = mitochondria)

• “Powerhouse” of the cell

• Generate cellular energy (ATP)

• More active cells like muscle cells have MORE mitochondria

• Both plants & animal cells have mitochondria

• Site of CELLULAR RESPIRATION (burning glucose)

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MITOCHONDRIASurrounded by a

DOUBLE membrane

Folded inner membrane called CRISTAE (increases surface areafor more chemical Reactions)

Has its own DNA

Interior called MATRIX

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Interesting Fact ---Interesting Fact ---

• Mitochondria Come from cytoplasm in the EGG cell during fertilization

Therefore …• You inherit your

mitochondria from your mother!

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Rod shape

Cell PowerhouseCell Powerhouse

Mitochondrion( mitochondria )

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Endoplasmic Reticulum - EREndoplasmic Reticulum - ER

Two kinds of ER ---ROUGH & SMOOTH

• Network of hollow membrane tubules• Connects to nuclear envelope & cell

membrane• Functions in Synthesis of cell products

& Transport

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Rough Endoplasmic Reticulum Rough Endoplasmic Reticulum (Rough ER)(Rough ER)

• Has ribosomes on its surface

• Makes membrane proteins and proteins for EXPORT out of cell

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Smooth Endoplasmic Smooth Endoplasmic ReticulumReticulum

• Smooth ER lacks ribosomes on its surface

• Is attached to the ends of rough ER

• Makes cell products that are USED INSIDE the cell

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Functions of the Smooth Functions of the Smooth ERER• Makes membrane

lipids (steroids)• Regulates calcium

(muscle cells)• Destroys toxic

substances (Liver)

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Endomembrane System

Includes nuclear membrane connected to ER connected to cell membrane (transport)

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RibosomesRibosomes• Made of PROTEINS and rRNA• “Protein factories” for cell• Join amino acids to make proteins• Process called protein synthesis

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RibosomesRibosomes

Can be attached to Rough ER

OR

Be free (unattached

) in the cytoplasm

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Golgi BodiesGolgi Bodies• Stacks of Stacks of flattened flattened

sacssacs• Have a shipping side Have a shipping side

((trans facetrans face) and ) and receiving side (receiving side (cis cis faceface))

• Receive Receive proteinsproteins made by ERmade by ER

• Transport vesiclesTransport vesicles with modified with modified proteins pinch off the proteins pinch off the endsends

Transport vesicle

CIS

TRANS

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GolgiGolgi

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LysosomesLysosomes• Contain Contain digestive digestive

enzymesenzymes• Break down Break down food, food,

bacteria,bacteria, and and worn out worn out cell partscell parts for cells for cells

• Programmed forProgrammed for cell cell death (apoptosis)death (apoptosis)

• Lyse (break open) & Lyse (break open) & release enzymesrelease enzymes to to break down & recycle break down & recycle cell parts)cell parts)

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Cilia & FlagellaCilia & Flagella

• Made of protein tubes called microtubules

• Function in moving cells, in moving fluids, or in moving small particles across the cell surface

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Cilia & FlagellaCilia & Flagella

• Cilia are shorter and more numerous on cells

• Flagella are longer and fewer (usually 1-3) on cells

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Cell Movement with Cilia Cell Movement with Cilia & Flagella& Flagella

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Cilia Moving Away Dust Particles Cilia Moving Away Dust Particles from the Lungsfrom the Lungs

Respiratory SystemRespiratory System

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VacuolesVacuoles• Fluid filled sacks for storage• Small or absent in animal cells• Plant cells have a large Central Vacuole• No vacuoles in bacterial cells

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VacuolesVacuoles

• In plants, they store Cell Sap

• Includes storage of sugars, proteins, minerals, lipids, wastes, salts, water, and enzymes

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Contractile Contractile VacuoleVacuole

• Found in unicellular protists like paramecia

• Regulate water intake by pumping out excess (homeostasis)

• Keeps the cell from lysing (bursting)

Contractile vacuole animation

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ChloroplastsChloroplasts• Found only in producers (organisms

containing chlorophyll)• Use energy from sunlight to make

own food (glucose)• Energy from sun stored in the

Chemical Bonds of Sugars

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ChloroplastsChloroplasts• Surrounded by DOUBLE

membrane• Outer membrane smooth• Inner membrane

modified into sacs called Thylakoids

• Thylakoids in stacks called Grana & are interconnected

• Stroma – gel like material surrounding thylakoids

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ChloroplastsChloroplasts

• Contains its own DNA

• Contains enzymes & pigments for Photosynthesis

• Never in animal or bacterial cells

• Photosynthesis – food making process

QUICK REVIEW!

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central vacuole

storage: food,

water or waste

mitochondriamake ATP in cellular respiration

chloroplastmake ATP & sugars in photosynthesis

cell wallsupport

cell membranecell boundarycontrols movementof materials in & out

recognizes signals

Golgi apparatus

finish & ship proteins

nucleuscontrol cellprotects DNA

endoplasmic reticulum

processes proteinsmakes membranes

lysosomedigestion & clean up

ribosomesmake proteins

cytoplasmjelly-like material

around organelles

nucleolusmake ribosomes

QUESTIONS?

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Cheek Cells

Onion Cells