1 Basic Structure of a Cell 2 Introduction to Cells Cells are the basic units of organisms Cells can only be observed under microscope Basic types of

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Basic Structure of a Cell

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Introduction to CellsIntroduction to CellsCells are the basic units of

organismsCells can only be observed under

microscopeBasic types of cells:

Animal Cell Plant CellBacterial

Cellcopyright cmassengale

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

copyright cmassengale

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Two Main Types Cells (with DNA contained in the

nucleus)

Plant Cell

Animal Cell


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Organelles are inside of all Organelles are inside of all cellscells

Very small size

Can only be observed under a microscope

Have specific functions

Found throughout cytoplasm


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Organelles Found in Cells

Examples of Organelles include:Lysosomes – digests & gets rid of wastes

-like a cell’s stomach/digestive system


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LysosomesLysosomes• Contain Contain digestive digestive

enzymesenzymes• Break down Break down food, food,

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

• 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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Lysosome DigestionLysosome Digestion

• Cells take in food by phagocytosis

• Lysosomes digest the food & get rid of wastes


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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/sugar)


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What do mitochondria What do mitochondria do?do?

Burns glucose sugar to

release energy (ATP)

Stores energy as ATP

“Power plant” of the cell


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Rod shapeSite of Cellular respiration –provides energy

Cell PowerhouseCell Powerhouse

Mitochondrion( mitochondria )


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

In All Cells:In All Cells:

Mitochondria


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Lies immediately against the cell wall in plant cells

Made of protein and phospholipids (fat)

Selectively permeable, has holes so some stuff passes through

Cell membrane

Surrounding all Surrounding all CellsCells


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

Selectively permeable (stuff goes in/out)

Cell membrane

Cell or Plasma Cell or Plasma MembraneMembrane


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Nonliving layerGives structure and shape to plant and bacterial cells

Not found in animal cells (animals have bones instead)

Cell wall

Plant cell organelle:Cell Plant cell organelle:Cell WallWall


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Jelly-like substance enclosed by cell membrane

Provides a medium for chemical reactions to take place

Cytoplasm

Cytoplasm of all Cytoplasm of all Cells Cells


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Contains organelles to carry out specific jobs

Examples: chloroplast & mitochondrion float in the cytoplasm

Cytoplasm

More on More on CytoplasmCytoplasm


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Largest animal cell organelleControls the normal activities of the cell

Contain the DNA (chromosomes/genes)

Control Organelle in all cells

Nucleus


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Each cell has fixed number of chromosomes that carry genes

Genes control cell characteristics

Nucleus


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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


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Chloroplasts Chloroplasts (found only in Plant (found only in Plant cells)cells)• Contains

enzymes & pigments for Photosynthesis

• Never in animal or bacterial cells

• Photosynthesis – food making process


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ChloroplastsChloroplasts• Found only in

producers/plants (organisms containing chlorophyll)

• Use energy from sunlight to make own food (glucose)

• Energy from sun stored in the Chemical Bonds of Sugars copyright cmassengale

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Dead layerLarge empty spaces present between cellulose fibers

Freely permeable

Cell wall

Plant Cell Only:Plant Cell Only:


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Plant CellPlant Cell

Made of cellulose which forms very thin fibers

Strong and rigidsupports plants so they stand upright

Cell wall


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Flat sides that protect and support the enclosed substances

Resist entry of excess water into the cell

Give shape to plant cells

Cell wallPlant Cell OnlyPlant Cell Only


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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 PlantsPlants have a cell membrane too!


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VacuolesVacuoles• Fluid filled

sacks for storage

• Small or absent in animal cells

• Plant cells have a large Central Vacuole


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large central vacuole= biggest organelle in plant cells

Contains cell sapSugars, proteins,

minerals, wastes, & pigments

Vacuole


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Kinds of Plant cells

Xylem cellsPollen

Guard Cells


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mitochondrion

nucleus

glycogen granule

cell membrane

cytoplasm Animal cellAnimal cell

No cell wall

No chloroplast

Roundish shapes

vacuole


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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 flat sides

Cell 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


Documents

1 Basic Structure of a Cell 2 Introduction to Cells Cells are the basic units of organisms Cells can only be observed under microscope Basic types of