Kingdom Monera(Archaebacteria & All bacteria are prokaryotes Characteristics: 1. No nucleus Eubacteria) 2. No membrane bound organelles 3. Smaller & less ribosomes 4. Most are smaller than eukaryotes 5. Most are single-celled organisms
Cell Structure & Function Capsule Sticky covering on the cell wall For protection and adherence Cell Wall Gives the cell shape Prevents osmosis from bursting the cell Cell Membrane Surrounds the cell Regulates transport Flagellum Whip like protrusion for movement
Cell Structure & Function Pili hairlike structures for sticking to another bacteria during conjugation Chromosome Single DNA molecule Not contained within a nucleus Plasmid(s) Genes located in small circular piece Ribosomes Create protein necessary for life functions
1. Classification by Kingdom A. Kingdom Archaebacteria: The Extremists Harsh environments Cell structures differ from other monerans B. Kingdom Eubacteria: true or traditional bacteria
2. Classification by Energy Source A. Autotrophs: organisms that produce their own food i. Photoautotroph: uses energy from sun for food ii. Chemoautotroph(chemosy nthesizers): obtain energy from inorganic substances
B. Heterotrophs: organisms that cannot produce their own food i. Photoheterotroph: uses sunlight for energy but obtains carbon from other organic source ii. Chemoheterotroph: obtain energy by using inorganic molecules and breaking them down
C. Saprophytes or Decomposers Obtain energy from breaking down dead organisms D. Parasites Life in/on another organism host at the expense of the host but without killing Pathogen: any disease causing bacteria
3. Classification by environment A. Archaebacteria 1. Methanogens Produce methane Live in swamps, guts of cows & humans Used to treat sewage & purify water 2. Halophiles Live in extremely salty places (eg. Dead Sea or Salt Lake) 3. Thermoacidophiles Live in hot acidic H 2 0 in hot springs Live in deep sea volcanic vents Some use inorganic compounds for energy (chemosynthetic)
B. Eubacteria 1. Heterotrophic bacteria Live everywhere Survive on organic molecules Some are parasites Some are saprophytes 2. Photosynthetic Autotrophs Cyanobacteria Perform plant-like photosynthesis Provide O 2 for aquatic environments 3. Chemosynthetic Autotrophs Use inorganic compounds for energy Some convert N 2 into N0 3 for plants
4. Classification by Gram Staining 1. Gram Positive Bacteria Cell wall made of protein and sugar Turn purple after gram staining 2. Gram Negative Bacteria Extra layer of lipid outside of cell wall Turn pink/red after gram staining Require different types of antibiotics to treat infections
5. Classification by Shapes 1. Spherical (coccus) Eg. Streptococcus and Pneumoncoccus 2. Rod-shaped (bacillus) Eg. Escherichia coli (E. coli) 3. Spiral (spirillum) Eg. Treponema pallidum (syphilis)
Bacterial Shapes
6. Classification by Cellular Respiration Process by which nutrients are broken down to provide energy A. Obligate aerobes Need oxygen to live (eg. Tuberculosis) B. Obligate anaerobes Killed by oxygen (eg. Clostridium tetani in deep wounds) C. Facultative anaerobes Can use oxygen if it is available (eg. E. coli in human intestines)
Reproduction 1. Binary Fission (asexual reproduction) Method of reproduction for most bacteria Occurs under normal conditions Process: 1. DNA replicates (ie. doubles) 2. Cell divides 3. Result: 2 identical daughter cells 2. Conjugation (sexual reproduction) DNA is exchanged between bacteria cells Cell to cell contact using pili Increases diversity
3. Transduction (sexual) Use of viruses to transfer DNA between bacteria cells Video clip 4. Transformation (sexual) Bacteria cells that pick up DNA from dead bacteria cells Video clip
Endospores Some bacteria can transform into dormant state called an Endospore A way to survive difficult conditions Involves the formation of a thick wall around itself They are able to resist: heat drought radiation
Diversity of Bacteria 1. 2 separate Kingdoms 2. Method of Obtaining Energy 3. Environment where they live 4. Cell Wall Gram Positive or Negative 5. Shape (circle, rod, spiral) 6. Cellular Respiration 7. Colony Appearance Colour Shape (paired, clumps, chains) Shininess
Practical uses for Bacteria Bacteria is both beneficial and essential for humans E. coli, which is present in the colon, metabolizes fecal material and allows animals to absorb the minerals and Vitamin K that is produced. Used in food production (cheese, yogurt) Decomposers(recycling of nutrients, supplying O 2 ) Nitrogen fixing bacteria in plants(used for growth) Antibiotic production
Practical Uses for Bacteria Bacteria are also used in the process of producing recombinant DNA DNA from another source is placed into the bacterial DNA This creating a new useful strain Utilizes bacteria to mass-produce proteins of specific interest like: blood clotting factor hormones insulin