Prokaryotic vs Eukaryotic Cells Major Cell Types Prokaryotic

Prokaryotic vs. Eukaryotic Cells

Major Cell Types Prokaryotic – (Bacteria and archaea) cells lack a membrane-bounded nucleus or membrane-bounded organelles. Eukaryotic – cells have membrane-bounded a nucleus and membrane-bounded organelles.

Prokaryotes Archaea Bacteria Extreme halophiles Extreme thermophiles Methanogens Cyanobacteria (blue-green algae)

Prokaryotic Characteristics § § § Strong Cell Wall Rotating Flagella Simple Interior Organization

Cell Walls § With peptidoglycan – Bacteria § Without peptidoglycan – Archaea – Plants – Fungi – Most protists

Rotating Flagella § § § Protein fibers 0, 1 or more Rotary “motor” uses proton gradient for energy

Simple Internal Organization § § § No membrane-bound nucleus No membrane-bound organelles Plasma membrane carries out some “organelle” functions – DNA separation – Folds containing pigments for photosynthesis

Botulism!

Cholera!

Black Death!

Flesh Eating Bacteria!

E. coli!

All caused by. . . Bacteria!

Bacteria Size: 1 -1. 4 m wide, 2 -6 m long Shapes: spherical (coccus) rod-shaped (bacillus) spiral (spirillum)

Bacterial Morphology

Key Bacteria Features § § § § § Cell wall – peptidoglycan strengthens Capsule/slime layer (glycocalyx) Flagellum – motility appendage Plasma membrane Cytoplasm (cytosol) Ribosomes Nucleloid Plasmids Thylakoids Sex pili

Bacteria Most bacteria living today “true bacteria. ” C Strong cell walls containing peptidoglycan (protein cross-linked carbohydrate) C Simple gene architecture C Photosynthetic - cyanobacteria (blue-green algae) CFolded plasma membrane CFolds contain photosynthetic pigments

Representative Prokaryotic (Bacterial) Cell

Archaea From the Greek for “ancient ones. ” Anaerobic (“without air”) Similarities to bacteria DNA Lipid cell membrane Exterior cell wall Metabolism based on ATP

Archaea Differences from bacteria irregular Also lobed, plate-shaped or simply eukaryotes DNA & RNA sequences closer to Inhabit extreme environments Lack peptidoglycan in cell walls Unique lipids in cell membrane processes Differences in basic biochemical

Eukaryotic Cells Far more complex! Bio. Flix: Tour Of An Animal Cell Bio. Flix: Tour Of A Plant Cell

Key Eukaryotic Cell Features § Membrane-bound nucleus – chromosomes § Membrane-bound organelles – Compartmentalization § Cytoskeleton

Review § Identify the major characteristics distinguish a cell as being prokaryotic. that

Review § Define the following key terms related to prokaryotic cells. cytosol nucleoid region capsule slime layer cell wall capsule flagellum plasma membrane cytoplasm (cytosol) ribosomes nucleloid plasmids thylakoids glycocalyx