1. KINGDOM BACTERIA SEC 12.2

2. Classifying Bacteria  Shape  Structure of cell walls  Source of food and energy  RNA Bacteria are prokaryotes! Bacteria and Science - Timeline of Knowledge Bacteria and Science - Timeline of Knowledge

3. Shape  Cocci (round)  Bacilli (rod shaped)  Spirilli (spiral Shaped) Different prefixes:  Diplo - describes cells arranged in pairs  Staphylo – describes cells arranged in clusters resembling grapes  Strepto – arranged in a chain 3 Types of Bacteria 3 Types of Bacteria

4. Cell Wall Structure  Gram positive bacteria Have a thick protein layer on their cell wall and stain purple Have a thick protein layer on their cell wall and stain purple  Gram negative bacteria Have a thin protein layer on their cell walls and stain pink Have a thin protein layer on their cell walls and stain pink

5. Source of Energy  Bacteria are found in almost every environment because they can use widely different energy sources.  Based on their energy source bacteria can be grouped into 4 major types: Photosynthetic Bacteria: (1) Photoautotrophs and (2) Photoheterotrophs Photosynthetic Bacteria: (1) Photoautotrophs and (2) Photoheterotrophs Chemosynthetic Bacteria: (3) Chemoautotrophs and (4) Chemoheterotrophs Chemosynthetic Bacteria: (3) Chemoautotrophs and (4) Chemoheterotrophs

7.  Aerobic requires oxygen for growth and metabolism requires oxygen for growth and metabolism  Obligate anaerobes dies when exposed to oxygen dies when exposed to oxygen  Facultative anaerobes can grow with or without oxygen can grow with or without oxygen  Saprotrophs feed on dead organisms or organic wastes feed on dead organisms or organic wastes  Parasite absorb nutrients from the body fluids of living hosts. absorb nutrients from the body fluids of living hosts.  Thermophiles grow at temp about 50C grow at temp about 50C  Psychrophiles grow best at temp below 15C and die when exposed to room temp. grow best at temp below 15C and die when exposed to room temp. Beneficial Bacteria Beneficial Bacteria Harmful Bacteria Harmful Bacteria

8. Quick Fact  Yogurt is live bacteria !  When children are placed on antibiotics their parents are told by the doctor to feed them yogurt. The yogurt will replace the bacteria that the antibiotic is killing.

9. Bacterial Reproduction  The main method of reproduction is asexual – only one parent is needed to reproduce BINARY FISSION Binary Fission Video ClipBinary Fission Video Clip (1:03) Binary Fission Video Clip Bacterial DNA is replicated. Bacterial DNA is replicated. The bacteria cell then undergoes cytokinesis and produces TWO daughter cells, that are completely identical to the original cell. The bacteria cell then undergoes cytokinesis and produces TWO daughter cells, that are completely identical to the original cell. Bacterial Reproduction Bacterial Reproduction

11. Other Forms of Reproduction  Bacteria do not undergo sexual reproduction in the true meaning of the word, however, they have 3 means of sharing genetic material with each other. 1. Conjugation 2. Transduction 3. Transformation

12. 1. Conjugation  This is the direct transfer of genetic material between two bacterial cells that are temporarily joined by a sex pilis (bridge).  DNA (called plasmids) is transferred one-way; one cell donates DNA and the mate receives the DNA.  It is generally the “male” bacteria that is able to produce a pili and send over information to the “female” bacteria.

13. http://fig.cox.miami.edu/~cmallery/150/gene/sf 14x1box.jpg The F+ cell is considered MALE The F- cell is considered FEMALE

14. Plasmids  They are small loops of DNA that are separate from the main chromosome  A method of genetic recombination in bacteria Combining genes so that the cells that are produced have different genes from the “parent” cells Combining genes so that the cells that are produced have different genes from the “parent” cells  They can only be transferred from one bacteria to another during conjugation The green is the bacterial DNA The red are the plasmids

15. 2. Transduction  Bacterial phages carry bacterial genes from one host cell to another.

16. 3. Transformation  This is the alteration of a bacterial cell’s genotype by the uptake of naked foreign DNA from the surrounding environment.  Many bacterial species posses on their surfaces proteins that are specialized for the uptake of naked DNA from the surrounding solution. These proteins specifically recognize and transport only DNA from closely related species of bacteria. These proteins specifically recognize and transport only DNA from closely related species of bacteria.

17. Bacterial Resistance  Over time bacteria that are exposed to antibiotics will evolve new resistant strains  For example: they can reduce the amount of antibiotic that enters the cell.  This can be accomplished via mutations or the transmission of genes between bacterial cells via “sexual reproduction”, specifically plasmids. Plasmids are circular double stranded DNA molecules that are separate from the chromosomal DNAPlasmids are circular double stranded DNA molecules that are separate from the chromosomal DNA Antibiotics Movie Clip Antibiotics Movie Clip

18.  The effectiveness of antibiotics is being greatly reduced. Why is this phenomenon occurring?Why is this phenomenon occurring?  Scientists have to start to develop new antibiotics to combat antibiotic resistance. Understanding Bacteria - Resistance (15:29) Understanding Bacteria - Resistance (15:29)

19. Life Cycle  We have seen how they replicate BUT  Some bacteria can have a dormant phase where they are able to survive in unfavourable environments.  They develop a tough outer covering that surrounds their DNA and a small amount of cytoplasm, they are called endospores.

20. Economic Importance And Uses for Humans Industrial Uses of Bacteria Industrial Uses of Bacteria Research Bacteria Research Snow Bacteria Snow Bacteria

21.  How Dirty Our Toilets? How Dirty Our Toilets? How Dirty Our Toilets?  Nuke Your Sponge Nuke Your Sponge Nuke Your Sponge 