Bacteria and Archaea

Cell Structure Prokaryote: no nucleus Chromosome & plasmids float freely in cytoplasm Ribosomes: create proteins Flagella: used in movement Pili: act as anchors Capsule: outer coating Endospore: “cocoon” to protect DNA in harsh times flagellum pili plasmid cell wall chromosome plasma membrance This diagram shows the typical structure of a prokaryote. Archaea and bacteria look very similar, although they have important molecular differences.

Prokaryotes are widespread on Earth. Prokaryotes can be grouped by their need for oxygen. obligate anaerobes are poisoned by oxygen obligate aerobes need oxygen facultative aerobes can live with or without oxygen The bacteria that causes TB lives in your lungs…which type is it?

Bacteria and archaea are structurally similar but have different molecular characteristics. Bacteria commonly come in three forms. rod-shaped, called bacilli spiral, called spirilla or spirochetes spherical, called cocci Lactobacilli: rod-shaped Enterococci: spherical Spirochaeta: spiral Spirochaeta:spiral Enterococci: spherical Archaea have many shapes.

Bacteria (aka Eubacteria) Common to most environments on Earth Identified by Gram Stain test Gram negative: stains pink (harder to treat because of thick capsule) Gram positive: stains purple (easier to treat) Treatments differ depending upon results GRAM NEGATIVE GRAM POSITIVE

Gram Stains Which is harder to treat? Gram-negative bacteria have a thin layer of peptidoglycan and stain red. Gram-positive bacteria have a thicker peptidoglycan layer and stain purple. Which is harder to treat? Name one way to treat bacterial infections.

Bacteria have various strategies for survival. Reproduce asexually- through binary fission (less diversity). Prokaryotes exchange genes during conjugation (more diversity). Bacteria may survive by forming endospores. conjugation bridge TEM; magnification 6000x

Not all bacteria are harmful, most are helpful… Bacteria helped create the ozone. Ex: cyanobacteria-autotrophic bacteria Create oxygen for life on earth Bacteria return nutrients to the soil in nature Ex: saprophytes Bacteria used in medicine Bacteria used in food To make cheese, bread, wine, yogurt, soy sauce But some are bad…

Brush, Floss, & Rinse Your Teeth! GINGIVITIS HEALTHY MODERATE PERIODONTITIS ADVANCED PERIODONTITIS

Archaea are like an evolved extreme bacteria. Let’s look at those…

Archaea Live in extreme environments 1) Methanogens: Anaerobic Produce methane gas as a waste product Habitat: Swamps, sewage, digestive tract

Archaea 2) Thermophiles Heat and acid loving prokaryotes Habitat: Deep sea vents, volcanoes, hot springs (230°F)

Archaea 3) Halophiles Thrive in areas of high salt concentration Salt normally dehydrates organisms Use salt to make energy

Name this bacteria shape! Cocci

Name this bacteria shape! Bacillus

Name these cell parts! Pili

Name the process shown in this animation. Binary Fission