Unit 5 Bacteria: Unicellular Organisms C H A P T E R 1 5 R E A D P. 2 9 3-305
Bacterial Cell Structure: Prokaryotic Single cellular no membrane bound organelles primitive Parts of Bacteria 1. Cell membrane 2. Cytoplasm 3. Ribosomes 4. DNA in a nucleoid region 5. Cell wall made of peptidoglycan for protection and support 6. Flagella movement 7. Pili used for reproduction (cilia)
https://www.youtube.com/watch?v=lg-1vv4-58m Bacteria facts https://ww w.youtube.c om/watch?v =qcn92mb Wxd4
Bacteria Cell Shape 3 major shapes 1. cocci round 2. bacilli rod shaped 3. spirilli spiral shape
Bacterial Taxonomy 1.Domain Archea 2.Domain Eubacteria
Domain Archea Means ancient Simple prokaryotic cells, app. 1-10 micrometers in size Contains all basic components of any cell BUT lack peptidoglycan in their cell walls. Live in most extreme environments preferring environments that typical organism would not be able to withstand. 1. Salt loving termed halophiles 2. Heat loving termed thermophiles 3. Methane loving termed methanogens
Domain Eubacteria Typical bacterial organisms prokaryotic 1-10 micrometers in size Cell walls do contain peptidoglycan
Metabolic Diversity of Bacteria Bacteria are very diverse in their nutritional requirements! 1. Photoautotrophs 2. Photoheterotrophs 3. Chemoautotrophs 4. Chemoheterotrophs Remember Autotroph and heterotroph refers to their carbon source. Autotrophs use carbon dioxide (CO 2 ) to make their food Heterotrophs consume organic molecules - glucose
1. Photoautotroph Capable of photosynthesizing these use light energy and CO 2 to produce organic molecules (glucose) and ATP (adenosine triphpshpate energy) Bacteria as well as plants and some protists use photosynthesis to make their own food
2. Photoheterotrophs Use light energy BUT require organic carbon molecules, such a proteins or carbohydrates (much larger that carbon dioxide). This nutrient type is found ONLY in Bactreria
3. Chemoautotrophs Use CO 2 for their carbon source BUT instead of light: they use various chemicals found in the environment for their energy source. This nutrient type is only found in Bacteria.
4. Chemoheterotrophs Use organic molecules for both carbon and energy requirements This nutrient type is found in several different organisms including bateria, some protists, fungi and animals.
Bacteria Reproduction
Bacteria: Nitrogen Fixers
Nitrogen Cycle
Bacterial Oxygen Requirements
Reproduction in Bacteria Bacteria reproduce through 2 reproductive methods: Sexual and Asexual. Bacteria Spend majority of time reproducing asexually (without sex). Very effective as there is no mate required. Population can increase very rapidly with very little time (quick life cycle. Unfortunately, with asexual reproduction offspring are genetically identical to the parent cell. Without variation, a change in the environment could wipe out the entire bacterial population. So if you would like to keep the bacterial population, some reproductive methods to induce variation are necessary periodically.
1. Asexual Reproduction Binary Fission https://www.youtube.com/watch?v=wvkphsn6utg
To begin the process, the parent cell will replicate its DNA so that it has two identical copies of genetic material. This DNA which is not bound within any organelle will simply attach to the cell membrane of the cell. Growth or increase in size of the cell will occur resulting in the two copies of DNA being farther apart from each other. Between these two DNA molecules, the cytoplasm and the cell membrane will split resulting in two identical cells.
2. Reproduction for Variation A. https://www.youtube.com/watch?v=ejkgapyawiq B. https://www.youtube.com/watch?v=hm8szafmlwg
C. https://www.youtube.com/watch?v=hzmrdx1g9oa D. https://www.youtube.com/watch?v=txsq-7bchuq
Transduction
What is the difference between a bacterial infection and a viral infection?