1 basic structure of a cell history of cell theory mid 1600s – anton van leeuwenhoek –improved...

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Basic Structure of a Cell

History of Cell Theory•mid 1600s – Anton van

Leeuwenhoek– Improved microscope, observed many living

cells

•mid 1600s – Robert Hooke – Observed many cells including cork cells– Named the cell

•1850 – Rudolf Virchow– Proposed that all cells come from existing cells

• SCI.9-12.B-2.1 - [Indicator] - Recall the three major tenets of cell theory (all living things are composed of one or more cells; cells are the basic units of structure and function in living things; and all presently existing cells arose from previously existing cells).

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•SCI.9-12.B-2 - [Standard The student will demonstrate an understanding of the structure and function of cells and their organelles.]

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*Cell Theory1. All organisms consist of 1 or

more cells.2. Cell is the smallest unit of

life.3. All cells come from pre-

existing cells.

Observing Cells (4.1)

•Light microscope– Can observe living cells in true color– Magnification of up to ~1000x– Resolution ~ 0.2 microns – 0.5 microns

Observing Cells (4.1)

•Electron Microscopes– Preparation needed kills the cells– Images are black and white – may be colorized– Magnifcation up to ~100,000

•Transmission electron microscope (TEM)

– 2-D image

•Scanning electron microscope (SEM)

– 3-D image

SEM

TEM

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*Introduction to Cells*Introduction to CellsCells are the basic units of organismsCells can only be observed under

microscopeBasic types of cells:

Animal Cell Plant CellBacterial

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*Number of CellsOrganisms may be:• Unicellular – composed of one cell• Multicellular- composed of many cells that may organize

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Prokaryotes include bacteria & lack a nucleus or membrane-bound structures called organelles

Eukaryotes include most other cells & have a nucleus and membrane-bound organelles (plants, fungi, & animals)

*Cells May be Prokaryotic or Eukaryotic

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SCI.9-12.B-2.3 - [Indicator] - Compare the structures and organelles

of prokaryotic and eukaryotic cells.

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*ProkaryotesNucleoid region contains the DNA

•Cell membrane & cell wall

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

•Only example is bacteria

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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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OrganelleOrganelless

Very small size

Can only be observed under a microscope

Have specific functions

Found throughout cytoplasm

• SCI.9-12.B-2.2 - [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm).

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CYTOSKELETON

MITOCHONDRION

CENTRIOLES

LYSOSOME

GOLGI BODY

SMOOTH ER

ROUGH ER

RIBOSOMES

PLASMA MEMBRAN

EFig. 4-15b, p.59

Chromatin

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Organelles Found in Cells

Examples of Organelles include:Endoplasmic reticulum (rough & smooth) – canals for movement

Golgi Bodies – wrap & export proteins

Nucleolus – makes ribosomes

Lysosomes – digests & gets rid of wastes

Ribosomes – makes proteins

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*Golgi Bodies• Stacks of Stacks of flattened flattened

sacssacs• Have a shipping side Have a shipping side

& a receiving side& a receiving side• Receive & Receive & modify modify

proteinsproteins made by ER made by ER• Transport vesiclesTransport vesicles

with modified with modified proteins pinch off proteins pinch off the endsthe ends

Transport

vesicle

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*Lysosome• Contain digestive Contain digestive

enzymesenzymes• Break down food and Break down food and

worn out cell parts worn out cell parts for cells for cells

• Programmed for cell Programmed for cell death (lyse & release death (lyse & release enzymes to break enzymes to break down & recycle cell down & recycle cell parts)parts)

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*Nucleolus• Cell may have Cell may have 1 1

to 3to 3 nucleoli nucleoli• Inside nucleusInside nucleus• DisappearsDisappears when when

cell dividescell divides• Makes ribosomesMakes ribosomes

that make that make proteinsproteins

• SCI.9-12.B-2.2 - [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm).

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*Smooth & Rough Endoplasmic Reticulum

Smooth ER lacks ribosomes & makes lipids also detoxifies poisons from medicine and alcohol

Rough ER has ribosomes on its surface & makes proteins to EXPORT

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Rod shape*Site of Cellular respiration

Cell PowerhouseCell Powerhouse

Mitochondrion(mitochondria )

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Active cells like muscles have more mitochondriaBurn sugars to produce energy ATP

In Animal Cells:In Animal Cells:

Mitochondria

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Lies immediately against the cell wall in plant cells

Made of protein and phospholipids

Selectively permeable

Cell membrane

*Surrounding the *Surrounding the CellCell

• SCI.9-12.B-2.2 - [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm).

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Living layerControls the movement of materials into and out of the cell

Selectively permeable

Cell membrane

*Cell or Plasma *Cell or Plasma MembraneMembrane

Read this!Proteins and carbohydrates on the outside

of cells give cells their “identity.” This lets the immune system know that the cells belong in that body.

Transplanted organs are often rejected by the body because the immune system recognized the proteins and carbs as not belonging to that person’s body.

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• SCI.9-12.B-2.2 - [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm).

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Jelly-like substance enclosed by cell membrane

Provides a medium for chemical reactions to take place

Cytoplasm

Cytoplasm of a Cytoplasm of a Cell Cell

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Contains organelles to carry out specific jobs

Examples: chloroplast & mitochondrion

Cytoplasm

More on More on CytoplasmCytoplasm

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Controls the normal activities of the cell

Contain the DNABounded by a nuclear membrane

Contains chromosomes

Control Organelle

Nucleus

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Each cell has fixed number of chromosomes that carry genes

Genes control cell characteristics

Nucleus

More on the More on the NucleusNucleus

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Contain the green pigment chlorophyll

Traps sunlight to make to make sugars (food)

Process called photosynthesis

Plant Cell OrganellesPlant Cell Organelles

Chloropla

st

• SCI.9-12.B-2.2 - [Indicator] - Summarize the structures and functions of organelles found in a eukaryotic cell (including the nucleus, mitochondria, chloroplasts, lysosomes, vacuoles, ribosomes, endoplasmic reticulum [ER], Golgi apparatus, cilia, flagella, cell membrane, nuclear membrane, cell wall, and cytoplasm).

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Chromoplast – gives plants colors other than green.

Amyloplast – stores starch in plants- found in potatoes

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Dead layerLarge empty spaces present between cellulose fibers

Freely permeable

Cell wall

Plant CellPlant Cell

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Plant CellPlant Cell

Made of cellulose which forms very thin fibers

Strong and rigidFound in plant cells

Cell wall

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Protect and support the enclosed substances (protoplasm)

Resist entry of excess water into the cell

Give shape to the cell

Cell wall

*Plant Cell*Plant Cell

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Have a large central vacuole

Surrounded by tonoplast

Contains cell sapSugars, proteins,

minerals, wastes, & pigments

*Plant Cell Organelles*Plant Cell Organelles

Vacuole

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Different kinds of Different kinds of plant cellsplant cells

Onion Epidermal Cells

Root Hair Cell

root hair

Guard Cells

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mitochondrion

nucleus

glycogen granule

cell membrane

cytoplasm Animal cellAnimal cell

No cell wall or chloroplastStores glycogen in the cytoplasm for food energy

vacuole

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Animal Cell OrganellesAnimal Cell Organelles

•Near the nucleus•Paired structures•Help cell divide•Not found in plant

cells

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Different kinds of Different kinds of animal cellsanimal cells

white blood cell

red blood cell

cheek cells

sperm

nerve cell

muscle cell

Amoeba

Paramecium

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*Similarities between *Similarities between plant cells and animal plant cells and animal

cellscellsBoth have a cell membrane surrounding the cytoplasm

Both have a nucleus

Both contain mitochondria

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*Differences between *Differences between plant cells and animal plant cells and animal

cellscellsAnimal cells Plant cells

Relatively smaller in

sizeIrregular shape

No cell wall

Relatively larger in size

Regular shapeCell wall present

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Animal cells Plant cells

Vacuole small or absent

Glycogen as food storage

Nucleus at the center

Large central vacuole

Starch as food storage

Nucleus near cell wall

*Differences between *Differences between Plant Cells and Animal Plant Cells and Animal

CellsCells

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Levels of OrganizationLevels of OrganizationCELLS (muscle cells,nerve cells)

TISSUES (muscle, epithelium)

ORGANS (heart, lungs, stomach)

ORGAN SYSTEMS (circulatory system)

ORGANISM (human)

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The cell is the Basic The cell is the Basic Unit of LifeUnit of Life

• Cell is the smallest unit of living organisms

• Unicellular organisms are made of one cell only

• The cells of multicellular organisms are specialized to perform different functions

– e.g. mesophyll cells for photosynthesis and root hair cells for water absorption

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Levels of organizationLevels of organization

• Cells are grouped together and work as a whole to perform special functions

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TissueTissue

•A group of similar cells to perform a particular function–Animals : epithelial tissue, muscular tissue

–Plants : vascular tissue, mesophyll

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OrganOrgan

• Different tissues group together to carry out specialized functions– Heart : consists of muscles,

nervous tissue and blood vessels

– Leaf : consists of epidermis, mesophyll and vascular tissue

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Stoma

Air Space

Spongy Mesophyll Cell

Chloroplast

The Structures of a Leaf (Plant Organ)

Palisade Mesophyll Cell

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The Structures of a Heart (Animal Organ)

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SystemSystem• Several organs and tissues work together

to carry out a particular set of functions in a co-ordinated way– Human : digestive, respiratory, excretory,

circulatory and reproductive systems– Plant : root and shoot systems

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Human Body SystemsHuman Body Systems Examples of systems : Digestive System Respiratory System Circulatory System Nervous System Reproductive System

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Examples of a Human Body System

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Examples of a Human Body System

The Respiratory System

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Examples of a Human Body System

Circulatory System

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Examples of a Human Body System

Nervous System

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It’s You!

Terms for your testRibosomesChloroplast*PhotosynthesisMitochondria*Prokaryotic*EukaryoticSmooth ERRough ER*Amyloplasts*ChromoplastsCell membrane

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Golgi bodiesChromatinCentrioles in centrosomeChromosomesNucleolusVacuoles*Difference b/w prokaryotic/eukaryotic smooth/rough ER plant/animal cell