Kingdom Monera (Bacteria and Archaebacteria)

Prokaryotes The smallest and most common of cells are prokaryotes. They: Exist almost everywhere on earth Are cells that do not have a nucleus Do not have membrane-bound organelles All prokaryotes are placed into one of two kingdoms: Eubacteria or Archaebacteria

Eubacteria Make up the larger of the two prokaryote kingdoms Generally are surrounded by a cell wall composed of complex carbohydrates Within the cell wall is the cell membrane that surrounds the cytoplasm

Bacteria Cell

Cyanobacteria Also known as the blue-green bacteria Are photosynthetic (Contain membranes that carry out the process of photosynthesis) Contain phycocyanin and chlorophyll a Can be found nearly everywhere on earth. Can survive in extremely hot environments and even extremely cold environment

Prochlorobacteria Prochlorobacteria are a newly discovered group of organisms. They contain chlorophyll a & b. They are more similar to chloroplasts of green plants. Only 2 species of prochlorobacteria have been discovered.

Archaebacteria Lack important carbohydrate found in cell walls Have different lipids in their cell membrane, types of ribosomes, and gene sequences Archaebacteria can live in extremely harsh environments They do not require oxygen and can live in extremely salty environments as well as extremely hot environments.

Identifying Prokaryotes Cell Shape Cell Wall Movement

1) Bacterium Shapes Cocci~ Sphere shaped bacteria Bacillus~ Rod shaped bacteria Spirrillium ~ Spiral shaped bacteria

Bacteria can be arranged in: -cluster -chains -colonies or pairs

2) Cell Walls To study bacterial cell walls, one must stain it. This is called gram staining. Chemical nature of a cell wall can be determined by gram staining Gram’s stain consists of 2 dyes: crystal violet (purple) and safranine (red). By finding out what color the cell produces when it is gram stained you can figure out the type of carbohydrates in the cell wall

Gram staining The bacteria will take up either one or the other stain. Gram-positive  bacteria with only one thick layer of carbohydrates and proteins will take up the crystal violet Staphylo- E. coli coccus Gram-negative  bacteria with a second, outer layer of lipid and carbohydrate molecules will take up the safranine

3) Bacterial Movement Some have 1 or more flagella Some lash, snake, or spiral forward Some secrete slimy stuff Some don’t move! http://www.microbiologybytes.com/video/motility.html

Movement Flagella ~ Tail like structure the whips around to propel the bacterium Cillia ~ Miniature flagella surround the cell that help to “swim” Non motile ~ Sticky cillia like structures that keep the bacterium from moving Cillia

4) Bacteria and their energy Autotrophs Make their own food from inorganic molecules Heterotrophs Consume organic molecules made by other organisms

Autotrophs Phototrophic autotrophs trap the energy of the sunlight Eg. Cyanobacteria Chemotrophic autotrophs obtain their energy from inorganic molecules

Heterotrophs Chemotrophic heterotrophs obtain their energy by taking in organic molecules then breaking them down and absorbing them Phototrophic heterotrophs use the sun’s energy but they also need organic compounds for nutrition

Review: What type of cells are the most common? prokaryotes What are the 4 ways we can identify bacteria? Cell shape, cell wall, movement, obtain energy What are the 3 basic shapes of bacteria? Rod (bacilli), sphere (cocci), spiral (spirilla) What is gram-staining? Gram positive (purple), gram negative (red) What are the 2 different ways bacteria obtain energy? Autotrophic, heterotrophic

Bacterial Respiration Bacteria need constant energy through respiration and fermentation Respiration is the process that involves oxygen and breaks down food for the release of energy. Fermentation enables cells to carry out energy production without oxygen

Bacterial Respiration Obligate Aerobes Obligate Anaerobes Facultative Anaerobes Cannot live without oxygen. Must live without oxygen Can live with or without oxygen

Example of an obligate anaerobe: Clostridium botulinum An example of an obligate anaerobe is Clostridium botulinum, which produces toxins. If these bacteria find their way into a place that is free of air (O2), and filled with food material, they will grow very quickly. As they grow, they produce toxins, or poisons, that cause botulism. Botulism produces paralysis and if the breathing muscles are paralyzed, death.

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Bacteria Reproduction In favorable conditions, bacteria can grow and divide quickly. They can reproduce in the following ways: Binary Fission Conjugation Spore Formation

Cellular organism copies its genetic information then splits into two identical daughter cells

Conjugation A type of Bacteria Sex Two organism swap genetic information, that contains the information such as a resistance to penicillin

Spore Formation: Endospore A type of dormant cell Highly resistant to environmental stresses Endospores are formed by cells in response to environmental signals that indicate a limiting factor for growth, such as exhaustion of an essential nutrient.

Importance of Bacteria Bacteria is often used in: Food Sourdough bread, cheese, yoghurt Industry Break down oil Medical/cosmetic procedures

Symbiosis Bacteria develop a close relationship with other organisms in which the bacteria and the other organism both benefit For example: the bacteria E. coli This is found in the human digestive tract. The intestine provides a warm safe home with lots of food. The bacteria then helps us to digest food and make some vitamins that we can’t produce by ourselves. For cattle, the bacteria in their intestines help them produce the enzymes necessary to break down cellulose, which is mostly in grass and hay. Bacteria helps cattle digest their food.

Other types of relationships Parasitism Bacteria exploit the host cell, injuring them Eg. Mychobacterium tuberculosis Mutualism Relationship in which two species live together in such a way that neither are harmed

Bacteria in the Environment Nutrient Flow Bacteria recycle and decompose, or break down, dead material Sewage Decomposition Ie. Bacteria capable of digesting the hydrocarbons in petroleum are often used to clean up oil spills Nitrogen Fixation Process by which nitrogen in the atmosphere is converted into a form that can be used by living things

Review Differentiate between: Name ways in which we use bacteria today Respiration and fermentation Obligate aerobes, obligate anaerobes, and facultative anaerobes Binary fission, conjugation, and spore formation Symbiosis, parasitism, and mutualism Name ways in which we use bacteria today