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3a - Prokaryotic Cells

What is it to be alive?

Prokaryotes vs. Eukaryotes

size

organelles (including nucleus)

DNA

ribosomes

Prokaryotes vs. Eukaryotes: Size

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Thiomargarita namibiensis

Exceptionally large bacteria Common prokaryotic cell shapes (Fig. 11.1)

Arrangements

Bacterial flagellum/a

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Flagellar Arrangements Bacterial movement by flagella

or “swim & twiddle”

axial filaments made of endoflagella

Bacterial Archaeal

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sheath stalk

prostheca

Other bacterial structures

peptidoglycan

Wall

Cytoplasmic/ plasma/cell membrane

Mycolic acid

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Why organisms make cells walls

Cytoplasmic/plasma/cell membrane

hopanoids Nitrosomonas: folded membrane for respiration

Rhodospirillum: folded membrane for photosynthesis

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Maintaining a charge difference

Passive

aquaporins

Tonicity Active Transport

Group Translocation

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cytoskeleton

Other prokaryotic internal structures (inclusions)

lipid

carboxysomes

sulfur

magnetite

“Bt” toxin

aka. gas vacuoles

Endospore: sporulation