Chapter 7Cellular structure and

FunctionPage 180

7.1 Cell Discovery• Robert Hooke looked

at bark to see cells!• Claim to fame =

“named the cell” after his room.

Anton van Leeuwenhoek• Built on Hooke’s ideas

and built a better microscope and saw many living things!

Cell Theory• 1. All living things are made of 1+ cells.

• 2. Cells are the basic units of structure and organization of living things.

• 3. Cells come from other cells.

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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

Cell

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

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Basic Structure of a Cell

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Cells May be Prokaryotic or Eukaryotic

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Prokaryotes

include bacteria & have NO NUCLEUS or membrane-bound structures called organelles. They have DNA

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Eukaryotic CellContain 3 basic cell

structures:• Nucleus• Cell Membrane• Cytoplasm with

organelles• Almost all cells

are eukaryotic (plants, animals…)

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Two Main Types of Eukaryotic Cells

Plant Cell

Animal Cell

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OrganelleOrganelless

Can only be observed under a microscope

Have specific functions

Found throughout cytoplasm

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Golgi Bodies• Stacks of Stacks of flattened flattened

sacssacs• Have a shipping Have a shipping

side & a receiving side & a receiving sideside

• Receive & Receive & modify modify proteinsproteins made by made by ERER

• FED-EX of the cell!FED-EX of the cell!Transpo

rt vesicle

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Lysosome• Contain digestive Contain digestive

enzymesenzymes• Break down food Break down food

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

• Cleans up the cell!Cleans up the cell!

– Lysol!Lysol!

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Nucleolus• Cell may have Cell may have 1 1

to 3to 3 nucleoli nucleoli• Inside nucleusInside nucleus• Makes ribosomesMakes ribosomes

Ribosomes• Makes Proteins

• “ribs are protein”

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Smooth & Rough Endoplasmic Reticulum

Smooth ER lacks ribosomes & makes proteins USED In the cell

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

MitochondriaMitochondria

• Provides Energy for cells

• Powerhouse of the cell

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Active cells like muscles have MOREmitochondria

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

Cell membrane

Surrounding the Surrounding the CellCell

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Controls the movement of materials into and out of the cell=

Selectively permeable

Cell membrane

Cell or Plasma Cell or Plasma MembraneMembrane

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Jelly-like substance enclosed by cell membrane

Chemical reactions can take place here

Cytoplasm

Cytoplasm of a Cytoplasm of a Cell Cell

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Organelles are in the cytoplasm

Cytoplasm

More on More on CytoplasmCytoplasm

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The “BRAIN” that controls the cellBounded by a nuclear membrane

Contains chromosomes

Control Organelle

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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Plant CellPlant Cell

Made of cellulose which forms very thin fibers

StrongFound in plant cells

Cell wall

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Protect and support

Give shape to the cell

Cell wall

Plant CellPlant Cell

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Storage of:Sugars, proteins,

minerals, wastes, & water

Vacuum!

Plant Cell OrganellesPlant Cell Organelles

Central Vacuole

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mitochondrion

nucleus

glycogen granule

cell membrane

cytoplasm Animal cellAnimal cell

No cell wall or chloroplast

vacuole

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Animal Cell OrganellesAnimal Cell Organelles

•Near the nucleus

•Help cell divide

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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

size

No cell wall

Relatively larger in size

Cell wall present

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Animal cells Plant cells

Vacuole small or not there

Glycogen as food storage

Large central vacuole

Starch as food storage

Differences between Plant Differences between Plant Cells and Animal CellsCells and Animal Cells