The CellThe Cell

And all its parts!And all its parts!

The cellThe cell

The basic unit of structure and function in The basic unit of structure and function in all living things.all living things.

The average cell is between 2 and 200µm The average cell is between 2 and 200µm  (micrometers). (micrometers).

To give you an idea of how big a micrometer is, To give you an idea of how big a micrometer is, the thickness of a strand of human hair ranges the thickness of a strand of human hair ranges from 50 to 200 micrometers.  Dark hair is from 50 to 200 micrometers.  Dark hair is usually thicker than blonde hair.usually thicker than blonde hair.

The smallest particle that can be seen by the The smallest particle that can be seen by the human eye is about 10 micrometers.  The human eye is about 10 micrometers.  The eyepiece of your microscope has a special tool eyepiece of your microscope has a special tool to measure micrometers.to measure micrometers.Cells AliveCells Alive

Entering (and exiting) the cellEntering (and exiting) the cell

CELL WALLCELL WALL

A stiff wall that surrounds A stiff wall that surrounds the cell membrane, giving the cell membrane, giving the cell a rigid boxlike the cell a rigid boxlike shapeshape

Function: protection & Function: protection & supportsupport

This structure is found in This structure is found in plant & bacteria cellsplant & bacteria cells

CELL MEMBRANECELL MEMBRANEForms the outside Forms the outside boundary that separates boundary that separates the cell from its the cell from its environmentenvironmentFunction: controls what Function: controls what comes in and out of the comes in and out of the cellcell

Cell Wall/ Cell MembraneCell Wall/ Cell Membrane

Cell Wall/Cell MembraneCell Wall/Cell Membrane

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NucleusNucleus

Acts as the “brain” of Acts as the “brain” of the cell or the control the cell or the control centercenter

Directs all of the cell’s Directs all of the cell’s activitiesactivities

Where DNA is foundWhere DNA is found

NucleusNucleus

Cells without a nucleus: prokaryotesCells without a nucleus: prokaryotes

Cells with a nucleus: eukaryotesCells with a nucleus: eukaryotes

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NucleusNucleus

The nucleus of the cell contains the The nucleus of the cell contains the genetic information (DNA)genetic information (DNA)

Nuclear MembraneNuclear MembraneSurrounds nucleusSurrounds nucleus

Made of two layersMade of two layers

Openings allow Openings allow material to enter material to enter and leave nucleus and leave nucleus

http://library.thinkquest.org/12413/structures.html

NucleolusNucleolus

Inside Inside nucleusnucleus

Contains Contains RNA to build RNA to build proteins proteins

http://library.thinkquest.org/12413/structures.html

ChromosomesChromosomes

In nucleusIn nucleus

Made of DNAMade of DNA

Contain Contain instructions for instructions for traits & traits & characteristics characteristics

http://library.thinkquest.org/12413/structures.html

CytoplasmCytoplasm

A gel-like fluid found throughout the entire A gel-like fluid found throughout the entire cell wherein the organelles are found.cell wherein the organelles are found.

It is constantly moving so the cell does not It is constantly moving so the cell does not need to propel itself.need to propel itself.

MitochondriaMitochondria

The “powerhouse” of The “powerhouse” of the cellthe cell

Produces energy for Produces energy for the cellthe cell

RibosomesRibosomes

–““Factories” that produce proteinFactories” that produce protein

Endoplasmic ReticulumEndoplasmic Reticulum

–Carry proteins and other materials Carry proteins and other materials from one part of the cell to anotherfrom one part of the cell to another

Endoplasmic ReticulumEndoplasmic ReticulumMoves materials Moves materials around in cellaround in cell

SmoothSmooth type: lacks type: lacks ribosomesribosomes

RoughRough type type (pictured): (pictured): ribosomes ribosomes embedded in embedded in surface surface http://library.thinkquest.org/12413/structures.html

Endoplasmic Reticulum & Endoplasmic Reticulum & RibosomesRibosomes

Golgi BodiesGolgi Bodies

The cell’s “mailroom”The cell’s “mailroom”

Receives proteins Receives proteins and other materials and other materials from the from the ER, packages them ER, packages them and distributes them and distributes them to other parts of the to other parts of the cell.cell.

VACUOLESVACUOLES

Storage area of the cellStorage area of the cell

Stores food and waterStores food and water

Plants have one large vacuole for waterPlants have one large vacuole for water

Some animal cells have them & others do Some animal cells have them & others do notnot

LysosomesLysosomes

Cell’s cleanup crewCell’s cleanup crew

Breaks down old cell parts and releases Breaks down old cell parts and releases the substances so they can be used again.the substances so they can be used again.

ChloroplastsChloroplasts

Capture energy from Capture energy from the sunlight and use it the sunlight and use it to produce food for to produce food for the cellthe cell

Found only in the Found only in the plant cellplant cell

EukaryotesEukaryotes•Nucleus has a permeable membrane surrounding it

•Nucleus contains the organism’s genetic material (DNA)

•Most organelles also have a membrane around them

•Mostly eukaryotic kingdoms are multicellular

Plant CellsPlant Cells Animal CellsAnimal Cells

Larger Larger vacuolesvacuoles

ChloroplastChloroplast

Cell wallCell wall

Cells have Cells have definite shapedefinite shape

Smaller vacuoles, Smaller vacuoles, some have no some have no vacuolesvacuoles

No cell wall and no No cell wall and no chloroplastchloroplast

More lysosomesMore lysosomes

More mitochondriaMore mitochondria

ProkaryotesProkaryotes

•Have no nucleus (lack a nucleus)

•Have only ribosomes, cytoplasm, and genetic material (DNA or RNA)

•Genetic material floats freely in the cytoplasm (No nucleus)

•Cell Wall and cell membrane

•ALL unicellular

•BacteriaKingdoms ONLY