THE CELLTHE CELL

Part One:Part One:

The Animal Cell OrganellesThe Animal Cell Organelles

What is a cell…What is a cell…

A cell is defined as the basic unit of all A cell is defined as the basic unit of all organisms. All cells come from pre-existing organisms. All cells come from pre-existing cells and all living things are composed of cells and all living things are composed of cells. Although each cell is different cells. Although each cell is different depending on it location in the body, they depending on it location in the body, they all are composed of the same smaller all are composed of the same smaller components called organelles. These components called organelles. These membrane-bound organelles each perform membrane-bound organelles each perform a specific task within the cell, but together a specific task within the cell, but together they compromise a fully functioning they compromise a fully functioning eukaryotic cell. Let’s take a look at a few eukaryotic cell. Let’s take a look at a few of these structures.of these structures.

Cell TheoryCell Theory

According to the Cell TheoryAccording to the Cell Theory

1.1. All organisms are composed of one or All organisms are composed of one or more cellsmore cells

2.2. The cell is the basic unit of organization in The cell is the basic unit of organization in organismsorganisms

3.3. All cells come from preexisting cellsAll cells come from preexisting cells

Developed by Robert Hooke (1665) and Developed by Robert Hooke (1665) and others that followed him.others that followed him.

So What’s the So What’s the Difference?Difference?

ProkaryoticProkaryotic

No NucleusNo Nucleus No Membrane-No Membrane-

Bound OrganellesBound Organelles

Examples:Examples:Virus, BacteriaVirus, Bacteria

EukaryoticEukaryotic

Nucleus PresentNucleus Present Membrane-Bound Membrane-Bound

OrganellesOrganelles

Examples:Examples:Animal Cells, Animal Cells, ProtistsProtists

NucleusNucleus

The nucleus is the The nucleus is the control center of control center of the cell.the cell.

Nuclear Nuclear MembraneMembrane

Contains Genetic Contains Genetic Material (DNA).Material (DNA).

NucleolusNucleolus

Bundle of Bundle of DNADNA

Involved in Involved in the making the making of ribosomesof ribosomes

CytoplasmCytoplasmLiquid part of cell, Liquid part of cell,

inside the cell inside the cell membrane, outside membrane, outside the nucleus, that is the nucleus, that is 97% water97% water

Suspends the cell’s Suspends the cell’s organellesorganelles

Site of chemical Site of chemical reactions in the cell.reactions in the cell.

Cell MembraneCell Membrane

Phospholipid bilayer Phospholipid bilayer with proteins with proteins scattered scattered throughoutthroughout

SemipermeableSemipermeable

Regulates what Regulates what enters and leaves enters and leaves the cellthe cell

RibosomesRibosomes

Organelle where Organelle where proteins are proteins are synthesizedsynthesized

Located on the Located on the Endoplasmic Endoplasmic ReticulumReticulum

Some also free in Some also free in cytoplasmcytoplasm

Endoplasmic ReticulumEndoplasmic Reticulum

Extension of nuclear Extension of nuclear membrane.membrane.

Found outside nucleus Found outside nucleus in cytoplasmin cytoplasm

Structure for the Structure for the assembly and assembly and transport of proteinstransport of proteins

MitochondriaMitochondria

Known as the Known as the “Powerhouse” of “Powerhouse” of the cellthe cell

Converts stored Converts stored energy in food to energy in food to useable energyuseable energy

Has own DNA Has own DNA

Golgi ApparatusGolgi Apparatus

Membranous, but Membranous, but not attached to not attached to nucleusnucleus

Prepares proteins Prepares proteins and other cell and other cell products for products for movement within movement within the cellthe cell

VacuolesVacuoles

Membrane bound Membrane bound spaces for temporary spaces for temporary storage of food, storage of food, enzymes, and other enzymes, and other materials materials

Animals have many Animals have many small vacuolessmall vacuoles

Much larger in plant Much larger in plant cellscells

LysosomesLysosomes

““Trash person” of Trash person” of the cellthe cell

Organelles that Organelles that contain digestive contain digestive enzymes which enzymes which break down large break down large particles for particles for removal from the removal from the cellcell

MicrotubulesMicrotubules

Thin cylinders Thin cylinders made of proteinsmade of proteins

Give support and Give support and structure to the structure to the cellcell

Make up the Make up the CytoskeletonCytoskeleton

CentrioleCentriole

A pair of cylinders A pair of cylinders composed of composed of microtubulesmicrotubules

Involved in animal Involved in animal cell division by cell division by separating the separating the genetic materialgenetic material

In Summary…In Summary…

In multicellular organisms, cells are In multicellular organisms, cells are highly specialized for certain highly specialized for certain functions—even though most contain functions—even though most contain the same types of organelles and the same types of organelles and DNA. However, the number and DNA. However, the number and kind of organelles within the cell will kind of organelles within the cell will determine its specific function determine its specific function depending on where the cell is depending on where the cell is located.located.

THE CELLTHE CELL

Part Two:Part Two:

The Plant CellThe Plant Cell

A Brief Intro…A Brief Intro…

Plant cells are very similar to animal Plant cells are very similar to animal cells and therefore contain many of cells and therefore contain many of the same organelles. the same organelles.

Plant cells are more rigid in structure Plant cells are more rigid in structure and the amount of water in the cell and the amount of water in the cell is important in support of the cell. is important in support of the cell.

PlastidsPlastids

Plastids are involved Plastids are involved in the storage of a in the storage of a variety of different variety of different things: food, things: food, proteins, chlorophyllproteins, chlorophyll

The color of the plant The color of the plant is usually caused by is usually caused by the contents of the the contents of the plastidsplastids

ChloroplastsChloroplastsA chloroplast is an A chloroplast is an

example of a plastid example of a plastid filled with chlorophyllfilled with chlorophyll

Like mitochondria, have Like mitochondria, have their own DNAtheir own DNA

Chlorophyll gives a plant Chlorophyll gives a plant its green colorits green color

Chlorophyll is used by the Chlorophyll is used by the plant during photo-plant during photo-synthesissynthesis

Cell WallCell Wall

Plants have an exterior Plants have an exterior cell wall outside of cell wall outside of their membranestheir membranes

The cell wall is composed The cell wall is composed mainly of cellulosemainly of cellulose

Has openings (plasmo-Has openings (plasmo-desmata) which desmata) which connect the cytoplasm connect the cytoplasm of neighboring cellsof neighboring cells

VacuoleVacuole

The vacuole of a plant cell The vacuole of a plant cell is similar to an animal in is similar to an animal in that it is filled mainly of that it is filled mainly of water.water.

The plant vacuole is much The plant vacuole is much larger and only one or larger and only one or two in a cell (roughly two in a cell (roughly 90% of the cell)90% of the cell)

Turgor PressureTurgor Pressure and the and the amount of water in the amount of water in the vacuole gives support to vacuole gives support to the cellthe cell

COMPARECOMPARE