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 scale
Of Things!
Why are cells so small?
Prokaryotic vs. Eukaryotic Cells
Prokaryotic
Primitive
Simple
DNA is in nucleiod region
No membrane bound
organelles
Smaller (1-3 µm Ave.)
Bacteria, Archae
Eukaryotic
modern
complex
DNA is in nucleus
membrane bound
organelles
Larger (10-30 µm)
Protists, Fungi, Plants
Animals
Prokaryotic Cell
Eukaryotic Cell
Plant Cell vs. Animal Cell
•Cell Wall
•Chloroplasts
•Central Vacuole
Plant Cell
Plant Cell vs. Animal Cell
•Centrioles
•Cilia and Flagella
•More Lysosomes
Animal Cell
Organelles: The Nucleus
Controls cell activities
Contains the DNA
(DNA = hereditary
material)
Parts:
Nuclear envelope
Pores
Nucleolus (RNA)
Organelles: Ribosomes
Ribosomes = site of protein synthesis
(can be free floating or attached to ER)
Organelles: ER (Endoplasmic Reticulum)
Rough ER = has ribosomes
Smooth ER = no ribosomes
So difference in function?
Rough has protein synthesis
occur on it and smooth does not
Form channels of membrane
for 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)
Function: Cellular Respiration releases energy for the cell to use
Parts:
Outer membrane
Inner Membrane
Cristae
Matrix
Organelles: Chloroplast (plastid)
Function: produce and store food
Parts:
Outer Membrane
Inner Membrane
Grana
Stroma
Chloroplast and Mitochondria
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•
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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: small
vacuoles
Plants: central
vacuole
•Stores toxins
•Water regulation
•Lysosomal
function
Outside
membrane=
tonoplast
Microbodies: convert harmful substances
into useful ones i.e. peroxisome
2H2O2  2H2O + 2O2
Peroxisome converts
hydrogen peroxide to
water 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
Desmosomes
Gap junctions
Tight Junctions
Cell Membrane: Fluid-Mosaic
Model
Cell Membrane: made of
phospholipids and proteins