Anatomy of Prokaryotes and Eukaryotes Prokaryotic Cell Structure Cell size, shapes, and arrangements Parts of a Prokaryotic Cell Glycocalyx: slime layer or capsule Fimbriae and sex pilus, flagella Cell wall and plasma membrane (g+, g-, mycobacteria, archaebacteria) Plasma membrane and material transport; osmosis Nuclear Area (Nucleoid), Plasmids, Ribosomes Endospores Eukaryotic Cell Structure Cytoplasm (open streets and city squares) Nucleus (library) Ribosomes (construction factories) Internal membrane System: ER, Golgi, Lysosomes Mitochondria (power station) Chloroplasts (food synthesis factory) Cytoskeleton (pulling ropes,& lumber)

Comparison of Prokaryotic and Eukaryotic Cells

Average size: µm  µm Basic shapes: Cocci Bacilli (rods) Spirilla Prokaryotic Cell Morphology

Cellular Arrangements

Anatomy of Prokaryotes and Eukaryotes Prokaryotic Cell Structure Cell size, shapes, and arrangements Parts of a Prokaryotic Cell Glycocalyx: slime layer or capsule Fimbriae and sex pilus, flagella Cell wall and plasma membrane (g+, g-, mycobacteria, archaebacteria) Plasma membrane and material transport; osmosis Nuclear Area (Nucleoid), Plasmids, Ribosomes Endospores Eukaryotic Cell Structure Cytoplasm (open streets and city squares) Nucleus (library) Ribosomes (construction factories) Internal membrane System: ER, Golgi, Lysosomes Mitochondria (power station) Chloroplasts (food synthesis factory) Cytoskeleton (pulling ropes,& lumber)

Outside cell wall Usually sticky: provides for attachment and protection Types A capsule is neatlyorganized gelatinous layer A slime layer is irregular & diffuse Extracellular polysaccharide allows cell to attach Capsules prevent phagocytosis Glycocalyx Figure 4.6a, b

Filaments outside cell wall Made of chains of flagellin protein Attached to a protein hook Anchored to the wall and membrane by the basal body Flagella Figure 4.8 H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Flagellar rotation is powered by the hydrogen ion gradient (proton motive force)

Flagella Arrangement Figure 4.7

Endoflagella In spirochetes Anchored at one end of a cell Rotation causes cell to move Axial Filaments Figure 4.10a

Fimbriae allow for attachment of cell to a substrate Pili are used to transfer DNA from one cell to another in conjugation Figure 4.11 Fimbriae and Pili

Anatomy of Prokaryotes and Eukaryotes Prokaryotic Cell Structure Cell size, shapes, and arrangements Parts of a Prokaryotic Cell Glycocalyx: slime layer or capsule Fimbriae and sex pilus, flagella Cell wall and plasma membrane (g+, g-, mycobacteria, archaebacteria) Plasma membrane and material transport; osmosis Nuclear Area (Nucleoid), Plasmids, Ribosomes Endospores Eukaryotic Cell Structure Cytoplasm (open streets and city squares) Nucleus (library) Ribosomes (construction factories) Internal membrane System: ER, Golgi, Lysosomes Mitochondria (power station) Chloroplasts (food synthesis factory) Cytoskeleton (pulling ropes,& lumber)

Prevents osmotic lysis Made of peptidoglycan (in eubacteria) Cell Wall Figure 4.6a, b

Peptidoglycan: Rows of Polysaccharide Crosslinked By Peptide Chains Figure 4.13a

Penicillin blocks cell wall cross- linking and causes mostly gram positive bacteria to lyse Lysozyme breaks NAG-NAM linkage and removes cell walls from gram positive and negative cells Gram Positive vs. Gram Negative Cell Envelope Anatomy

Steps 1.Primary stain (CV) 2.Mordant (iodine) 3.Decolorizer (ethanol-acetone) 4.Counterstain (safranin) Gram-positive Alcohol dehydrates peptidoglycan CV-I crystals do not leave --> purple Gram-negative Alcohol dissolves outer membrane and leaves holes in peptidoglycan CV-I washes out --> pink Gram Stain Mechanism

Differential Stains: Gram Stain Figure 3.10b

Mycobacteria (e.g. Mycobacterium tuberculosis, M. leprae) have cell envelopes similar to gram negatives but employ waxy mycolic acid instead of LPS in outer membrane Mycoplasmas (e.g. Mycoplasma pneumoniae) Lack cell walls Include unique mycosterols in plasma membrane add strength Archaeans (two main configurations) 1.Wall-less 2.Walls of pseudomurein (uses NAT instead of NAM and different amino acids for cross- bridges) Atypical Cell Walls

Cells that retain a basic stain (carbolfuchin)in the presence of acid- alcohol are called acid-fast. Non–acid-fast cells lose the basic stain when rinsed with acid- alcohol, and are usually counterstained (with a different color basic stain) to see them. Important in identifying Mycobacterium species that cause leprosy and tuberculosis Differential Stains: Acid-Fast Stain Figure 3.11