TSW investigate and understand the life functions of Monerans BACTERIA TSW investigate and understand the life functions of Monerans

Bacteria are PROKARYOTES Pro- Before Karyon- Nucleus Simplest forms of life are prokaryotes Earth’s first cells were prokaryotes

Prokaryote Diversity Earth’s most abundant life forms Capable of surviving in many different environments Capable of getting energy from many different sources

Prokaryote Review Mostly single-celled NO nucleus or organelles Circular chromosomes Cell walls Mostly asexual Anaerobic or aerobic Heterotrophic or autotrophic

Classifying Prokaryotes Until recently, classified in one kingdom- MONERA Now, 2 Kingdoms…what are they?

ARCHAEBACTERIA No peptidoglycan in their cell wall DNA sequences are more similar to those of Eukaryotes than Eubacteria Live in extremely harsh environments

Types of Archaebacteria Methanogens: Produce methane; anaerobic Halophiles: “salt lovers” Thermophiles: “heat lovers”

EUBACTERIA Larger of the 2 Kingdoms Tremendous variety…live almost anywhere Cell wall of peptidoglycan Usually contain 1 or 2 cell membranes

Types of Eubacteria Parasitic heterotrophs: Streptococcus Saprophages: “Death-eaters” Chemosynthetic Autotrophs: Rhizobium Photosynthetic Autotrophs: Blue-green algae

Identifying Bacteria Shape Cell Wall How they move How they obtain energy

Bacteria are named by SHAPE Cocci (ball-shaped) Streptococcus mutans Bacillus (rod-shaped) Clostridium botulinum Spirilli (spiral-shaped) Treponema palladium

Metabolic Diversity Best illustration of prokaryote diversity 2 main groups of prokaryotes: Autotrophs Heterotrophs

Heterotrophs Chemoheterotrophs: must take in organic molecules for both energy and a supply of carbon We are chemoheterotrophs. What does this mean? Photoheterotrophs: photosynthetic, but must still take in organic compounds for carbon

Autotrophs Photoautotrophs: use light energy to convert CO2 and H2O to carbon compounds and oxygen Found anywhere light is plentiful (Near the surfaces of lakes, streams, & oceans)

Autotrophs Chemoautotrophs: do NOT require light as a source of energy, instead obtain energy from chemical reactions Where would we find these?

Releasing Energy Obligate Aerobes: MUST have a constant supply of oxygen Obligate Anaerobes: MUST live in the absence of oxygen Facultative Anaerobes: Can survive with or without oxygen

Growth and Reproduction If food and space were unlimited, bacteria could grow & divide continuously 3 Methods Binary Fission Conjugation Spore Formation

Binary Fission Asexual (does not involve exchange of genetic info) Bacterium doubles in size, replicates its DNA & divides in half, producing 2 identical daughter cells

Conjugation Sexual (exchange of genetic material between bacteria) A hollow bridge forms between two bacteria and genes move from one cell to another

Spore Formation Spores form when growth conditions are unfavorable Spores remain dormant until conditions improve

Importance of Bacteria Producers that capture energy by photosynthesis Decomposers- breaking down the nutrients in dead matter & the atmosphere Fix nitrogen Human uses (food, digestion, medicines)

Human Uses