cellular structure chapter 4. eubacteria archaea eukarya
TRANSCRIPT
Cellular Structure
Chapter 4
Eubacteria
Archaea
Eukarya
Eubacteria
Archaea
Eukarya
AnimaliaFungiPlantaeProtista
Monera (defunct)
Bacterial Structure
Outwardly, there is little to go by in bacterial structure
Bacteria may be of various shapes (morphologies)
Coccus = Spherical
Bacillus = Rod
Spiral = Spiral
Pleomorphic = Varied, Undefined
On a microscopic level there are layers of structure.
Glycocalyx = Outer Coating.
Flagella = Motive structures
Fimbriae and Pili = Attachment
Bacteria are divided into two large groups based on overall cellular structure
Gram Positive vs. Gram Negative
Gram Identity is about cell structure more than staining
Gram Positive = Single Membrane
Gram Negative = Double Membrane
EXCEPTION Mycobacterium
EXCEPTION Mycoplasma
Even exceptions to normal Gram staining can be classified by their overall structure and genetics.
Internal structure in bacteria is limited, but organized.
Specialized internal structures are found in some bacteria.
EndosporesG+ structure to go dormant.
MagnetosomesMagnetite crystals for alignment
Storage Granules PHB Energy Storage
Eukarya Structure
Eukarya externally lack the complexity of Bacteria but are more internally structured
There are three classes of organelles.
Non-membrane BoundRibosomes, flagella, etc.
Endomembrane SystemNuclear Membrane, ER, etc.
Non-Endomembrane Membrane-BoundMitochondria and Plastids
Non-Membrane Organelles
A Note on Evolution
Ribosomes
Public Domain - PDB
Endomembrane System
Nucleus
Cell Nuclei inHeLa Cells
Public Domain Image-Wikipedia
The Nucleus has numerous functions
Contains the DNA of the Cell
Controls access to the DNA
Regulates division of the DNA
Endomembrane System
Wikimedia Commons
Mitochondria and Plastids
Chloroplasts
These organelles share a number of unique characteristics
Internal DNA Each possess a small circular piece of DNA
RibosomesEach possess ribosomes internal to their structure
Binary FissionBoth reproduce independent of the cell cycle.
Endosymbiotic Theory
Aerobic Eubacteria
Photosynthetic Eubacteria
Protoeukaryote
Aerobic Eukaryote
Photosynthetic Eukaryote
Various lines of evidence support this theory.
Organelle ribosomes more closely resemble bacterial ribosomes than eukaryotic ribosomes.
DNA of Mitochondria is closely related to Rickettsia bacteria.
DNA of Chloroplasts is closely related to blue-green photosynthetic bacteria.