The Cell

The 3 Principles of Cell Theory:

• The cell is the basic unit of life

• All cells come from pre-existing cells (mitosis, meiosis, fertilization)

• All organisms are made of one or more cells

The scaleOf Things!

What are cells so small?

Prokaryotic vs. Eukaryotic Cells

Prokaryotic EukaryoticPrimitive modernSimple complexDNA is in nucleiod regionDNA is in nucleusNo membrane bound membrane boundorganelles organellesSmaller (1-3 µm Ave.) Larger (10-30 µm)Bacteria, Archae Protists, Fungi,

PlantsAnimals

Prokaryotic Cell

Eukaryotic Cell

Plant Cell vs. Animal Cell

Plant Cell

•Cell Wall•Chloroplasts•Central Vacuole

Plant Cell vs. Animal Cell

Animal Cell

•Centrioles•Cilia and Flagella•More Lysosomes

Organelles: The Nucleus

Controls cell activitiesContains the DNA(DNA = hereditary

material)Parts:Nuclear envelopePoresNucleolus (RNA)

Organelles: Ribosomes

Ribosomes = site of protein synthesis(can be free floating or attached to ER)

Organelles: ER (Endoplasmic Reticulum)

Rough ER = has ribosomesSmooth ER = no ribosomes

So difference in function?Rough has protein synthesisoccur on it and smooth does not

Form channels of membranefor transport of materials in cell

Organelles: Golgi Apparatus

Sorts and packages materials

Endomembrane System

Organelles: Lysosomes

Contain hydrolytic (digestive) enzymes

Breakdown worn out parts of the cell

Organelles: Mitochondria (powerhouse)

Parts:Outer membraneInner MembraneCristaeMatrix

Function: Cellular Respiration releases energy for the cell to use

Organelles: Chloroplast (plastid)

Function: produce and store food

Parts:Outer MembraneInner MembraneGranaStroma

Chloroplast and Mitochondria

• Semi-autonomous organelles

• Both have double membranes

• Both have their own DNA

• Both make some of their own proteins

• Cells on their own at one time??

Organelles: Vacuoles

Animals: smallvacuoles

Plants: centralvacuole•Stores toxins•Water regulation•Lysosomal function

Outside membrane=tonoplast

Microbodies: convert harmful substancesinto useful ones i.e. peroxisome

2H2O2 2H2O + 2O2

Peroxisome convertshydrogen peroxide towater and oxygen

Cytoskeleton: movement of organelles,shape and support

Microtubules, microfilaments, intermediate filaments

Organelles: Cilia and Flagella

Structure of cilia and flagella(9 + 2 arrangement)

Cell to Cell Junctions: Plants-Plasmodesmata

Cell to Cell Junctions: Animal Cells

DesmosomesGap junctionsTight Junctions

Cell Membrane: Fluid-Mosaic Model

Cell Membrane: made of phospholipids and proteins