Cellular Structure and Cellular Structure and FunctionFunction

7.1 Cell Discovery and Theory7.1 Cell Discovery and Theory7.2 The Plasma Membrane7.2 The Plasma Membrane

The Discovery of the CellThe Discovery of the Cell Cell: The basic structural and functional Cell: The basic structural and functional

unit of all living organismsunit of all living organisms

Robert HookRobert Hook 16651665 Looked at corkLooked at cork Used the word “cell” to describe what he Used the word “cell” to describe what he

sawsaw

Anton van Leeuwenhoek Anton van Leeuwenhoek Designed his own microscope after reading Designed his own microscope after reading

a book written by Hook!a book written by Hook! First to study First to study livingliving cells under microscope cells under microscope

The Cell TheoryThe Cell Theory

3 parts: 3 parts: 1.1. All living things are made of cellsAll living things are made of cells2.2. The cell is the basic unit of structure and The cell is the basic unit of structure and

organization in all living organisms organization in all living organisms 3.3. All cells can only come from other living All cells can only come from other living

cells, cells pass on genetic information to cells, cells pass on genetic information to their daughter cellstheir daughter cells

Video ClipVideo Clip

MicroscopesMicroscopes

Development of this technology allowed Development of this technology allowed scientists to actually see cells for the first scientists to actually see cells for the first timetime

Compound Light MicroscopesCompound Light MicroscopesHow do you calculate total magnification?How do you calculate total magnification?Needed to look at cellsNeeded to look at cells

Electron MicroscopesElectron MicroscopesDeveloped during WWIIDeveloped during WWIINeeded to see the smaller things inside of cellsNeeded to see the smaller things inside of cells

Cell MembranesCell Membranes Cell Membrane and plasma membrane mean the same thingCell Membrane and plasma membrane mean the same thing The Cell Membrane is made of lipids and transport proteinsThe Cell Membrane is made of lipids and transport proteins

There are two layers of lipids, so it is sometimes called a Lipid bi-layerThere are two layers of lipids, so it is sometimes called a Lipid bi-layer The proteins float around in the lipidsThe proteins float around in the lipids

Why is it called a Fluid Mosaic Model?Why is it called a Fluid Mosaic Model? The membrane never actually stops movingThe membrane never actually stops moving

Selectively Permeable: The cell membrane can actually choose what moves Selectively Permeable: The cell membrane can actually choose what moves into and out of the cell!into and out of the cell!

Two Basic Cell TypesTwo Basic Cell Types

Virus

Eukaryotic cells

Prokaryotic cells

Major Parts of VirusesMajor Parts of Viruses

Protein shellProtein shellNucleic acid (DNA or RNA)Nucleic acid (DNA or RNA)

VirusesViruses Major Structures: Major Structures:

Not a cell!Not a cell! DNA or RNA core in some kind of coat organization: DNA/RNA DNA or RNA core in some kind of coat organization: DNA/RNA

just floats aroundjust floats around Complexity and OrganizationComplexity and Organization

No complexityNo complexity No organizationNo organization

How do we get more viruses?How do we get more viruses? Can not reproduce without a host cellCan not reproduce without a host cell

Is it a cell?Is it a cell? Not a cellNot a cell

EX: Ebola, West NileEX: Ebola, West Nile

Major Parts of Prokaryotic CellsMajor Parts of Prokaryotic Cells

DNADNACytoplasmCytoplasmCell membraneCell membrane

Prokaryotic CellsProkaryotic Cells Major Structures:Major Structures:

Free floating DNA within cytoplasmFree floating DNA within cytoplasm Cell MembraneCell Membrane Usually chromosome (DNA) is in a loop Usually chromosome (DNA) is in a loop

Complexity and OrganizationComplexity and Organization Some organizationSome organization Little complexityLittle complexity

How do we get more prokaryotic cells?How do we get more prokaryotic cells? Cell reproducesCell reproduces

Is it a cell?Is it a cell? Always s Single-Celled organismAlways s Single-Celled organism

Ex: Bacteria, Cholera, Ex: Bacteria, Cholera, E.coliE.coli

Major Parts of Eukaryotic CellsMajor Parts of Eukaryotic CellsNucleusNucleusDNA (chromatin vs. chromatid)DNA (chromatin vs. chromatid)Cytoplasm Cytoplasm Cell membraneCell membraneMembrane Bound OrganellesMembrane Bound Organelles

Eukaryotic CellsEukaryotic Cells Major Structures:Major Structures:

Chromosomes (DNA) is found within Chromosomes (DNA) is found within a a nucleusnucleus

Contains membrane bound organellesContains membrane bound organelles Complexity and OrganizationComplexity and Organization

Highly organizedHighly organized Very complexVery complex

How do we get more eukaryotic How do we get more eukaryotic cells?cells? Cell reproducesCell reproduces

Is it a cell?Is it a cell? Single-cellSingle-cell Multi-celled organismsMulti-celled organisms

Ex: Plants, Animals, You, Protozoa, Ex: Plants, Animals, You, Protozoa, FungiFungi

Organelles in Eukaryotic Cells

7.3 Structures and Organelles

Cell Wall (#4)

-only in plant cells

-provides physical

protection and support

-made of a starch

____11

Cell (Plasma) Membrane (below #1, red line) acts as a boundary layer to contain the cytoplasm

(fluid in cell) selectively permeable: able to select chemicals that

pass in and out of cells

Endoplasmic Reticulum (#2 and #6)-Transports chemicals between cells and within cells-Rough ER (#6) has ribosomes while Smooth ER does not (#2)

____11____11

Ribosomes (#6 small red dots)

-Site where proteins are made

Nucleus (#10) -contains DNA

-selectively permeable to control movement in or out, like the cell membrane

____11

____1110____________

Vacuole (#9)- produces turgor pressure against cell wall for support  - stores water and various chemicals  - much smaller in animal cells

____11

____11

9_____

Cytoplasm (#7)-"molecular soup" -holds together all of the cell's organelles,

and divides the organelles within the cell.

___7

Mitochondria (#8)

-the major energy production center in eukaryotes

_____8

Golgi (#11)-consists of stacks of sacs

-packages materials for export from the cell

____11 ____11

Chloroplast (no number, green organelle) Function in photosynthesis to make sugar

from sunlight Found only in plants

Plant and Animal Cells