Bacteria and Archaea and Protists Chapter 27 Sections Chapter 28 Sections 28.1 and 28.7

Morphology Cocci Bacilli Spirilla

Cell Wall What are the functions of the cell wall in prokaryotes? Maintain cell shape Protection Prevent bursting in hypotonic environment Made of peptidoglycan Why is some food preserved by salting it? Hypertonic environment plasmolyzes bacterial cells

Cell Wall Structure What is the composition of prokaryotic cell walls? Peptidoglycan Exact components vary among species Some antibiotics work by preventing formation of cross-links in peptidoglycan

Gram+/Gram- Gram positive bacteria: ◦ Stains blue/violet Stains blue/violet ◦ Simple cell walls with lots of peptidoglycan Simple cell walls with lots of peptidoglycan ◦ Purple/blue stain is trapped in cell wall Purple/blue stain is trapped in cell wall ◦ Less threatening pathogens: tooth decay, strep throat Less threatening pathogens: tooth decay, strep throat Gram negative bacteria ◦ More complex cell walls with less peptidoglycan More complex cell walls with less peptidoglycan ◦ Blue dye washes out so they stain pink (first dye) Blue dye washes out so they stain pink (first dye) ◦ Outer membrane covers cell wall Outer membrane covers cell wall ◦ More pathogenic than gram+; typhus gonorrhea More pathogenic than gram+; typhus gonorrhea ◦ Lipopolysaccharides in outer membrane often toxic Lipopolysaccharides in outer membrane often toxic

Adherence Capsule: ◦ Gelatinous secretion that helps cell adhere to host Pili: ◦ Surface appendages used for conjugation or adherence to host

Bacterial Movement Flagella Spirochetes move via axial helical filaments Glide via slimy chemical secretion Many are capable of taxis in heterogeneous environment

Basic Cell What does the basic prokaryotic cell look like? What does the basic prokaryotic cell look like? Nucleoid region one circular piece of DNA Little protein associated with bacterial genome Bacterial chromosome often called genophore

Metabolic Diversity What are the four possible modes of bacterial nutrition? Photoautotrophs Chemoautotrophs Photoheterotrophs Chemoheterotrophs – most bacteria are in this group

Reproduction Binary fission, no mitosis or meiosis What are the methods of genetic recombination? Transformation Conjugation Mutations What are endospores?

Disease Exotoxins release poisons such as botulism and cholera Endotoxins seen in outer membrane of gram negative bacteria (Salmonella)

Three Groups Methanogens Extreme halophiles Extreme thermophiles

Chapter 28: Protist Diversity Unicellular Rely on use of nucleus, endoplasmic reticulum, Glogi apparatus, and lysosomes Nutritionally diverse ◦ Photoautotrophs-contain chloroplasts ◦ Heterotrophs ◦ Mixotrophs-photosynthetic and heterotrophic Reproduction and life cycles are highly varied-asexual or sexual reproduction

Secondary Endosymbiosis Red algae and green algae were ingested in the food vacuole of heterotrophic eukaryotes and became endosymbionts

Symbiotic relationships Photosynthetic dinoflagellates provide nourishment to coral polyps that build coral reefs Wood digesting protists inhabit termite guts

Stains violet/blue

Where do photosynthesis and respiration take place?