1. BACTERIA chapter 24  Characteristics  no membrane bound nucleus  single chromosome  reproduce by fission  great metabolic diversity

4.  Some archaea live in extreme environments and are called extremophiles  Extreme halophiles  live in highly saline environments  Extreme thermophiles  thrive in very hot environments  Methanogens  produce methane as a waste product  strict anaerobes and are poisoned by O 2  found in swamps and marshes, in the guts of cattle, and near deep-sea hydrothermal vents Archaebacteria

5. Eubacteria  Includes most familiar bacteria  Have fatty acids in plasma membrane  Most have cell wall; always includes peptidoglycan  network of modified sugars cross-linked by polypeptides  which maintains cell shape, protects the cell, and prevents it from bursting in a hypotonic environment  Classification based largely on metabolism

6.  Photoautotrophic  Cyanobacteria  get e - and H + from H 2 O and release free O 2  light trapping pigments and e - transfer chains  Chemoautotrophic  Anaerobes  free oxygen kills them  get e - and H + from gaseous H 2, H 2 S and other inorganic compounds

7.  Chemoheterotrophic  saprotrophic  must consume organic molecules for energy and carbon  known as decomposers  Photoheterotrophic  use light for energy  must obtain their carbon in organic form

9. Bacterial Behavior  Bacteria move toward nutrient-rich regions  Taxis  the ability to move toward or away from a stimulus  Chemotaxis  the movement toward or away from a chemical stimulus  Aerobes move toward oxygen; anaerobes avoid it  Photosynthetic types move toward light  Magnetotactic bacteria swim downward

10. The Role of Oxygen in Metabolism  Prokaryotic metabolism varies with respect to O 2  Obligate aerobes  require O 2 for cellular respiration  Obligate anaerobes  poisoned by O 2 and use fermentation or anaerobic respiration, in which substances other than O 2 act as electron acceptors  Facultative anaerobes  can survive with or without O 2

11. Nitrogen Metabolism  Nitrogen is essential for the production of amino acids and nucleic acids  Prokaryotes can metabolize nitrogen in a variety of ways  In nitrogen fixation, some prokaryotes convert atmospheric nitrogen (N 2 ) to ammonia (NH 3 )

12. Adaptations of Prokaryotes  The ongoing success of prokaryotes is an extraordinary example of physiological and metabolic diversification  Prokaryotic diversification can be viewed as a first great wave of adaptive radiation in the evolutionary history of life

13.  Bacteria contain the following structures  DNA (circular)  cell wall (peptidoglycan)  thin plasma membrane  flagella  cilia

14. Gram Stain Gram stain

15.  Stained bacteria  Gram negative  red  less peptidoglycan  outer membrane can be toxic  Gram positive  purple  simpler walls with a large amount of peptioglycan

16. Peptido- glycan layer Cell wall (a) Gram-positive bacteria Plasma membrane

17. (b) Gram-negative bacteria Plasma membrane Peptidoglycan layer Cell wall Outer membrane Carbohydrate portion of lipopolysaccharide

18. Bacterial Shapes  Cocci  round  Bacilli  rod  Spirilla  spiral

19. Bacterial Arrangements  Staphlo  Grape like clusters  Strepto  chains  Diplo  pairs

20. Bacteria Reproduction  Prokaryotes reproduce quickly by binary fission and can divide every 1–3 hours  Key features of prokaryotic biology allow them to divide quickly  They are small  They reproduce by binary fission  They have short generation times

21. :

22. Prokaryotic Fission Prokaryotic fission

23.  Prokaryotes have considerable genetic variation  Three factors contribute to this genetic diversity  Rapid reproduction  Mutation  Genetic recombination Genetic Variation

24. Genetic Recombination  Genetic recombination, the combining of DNA from two sources, contributes to diversity  Prokaryotic DNA from different individuals can be brought together by  Transformation  Transduction  Conjugation  Movement of genes among individuals from different species is called horizontal gene transfer

25. Transformation and Transduction  A prokaryotic cell can take up and incorporate foreign DNA from the surrounding environment in a process called transformation  Transduction is the movement of genes between bacteria by bacteriophages (viruses that infect bacteria)

26. 1 Phage infects bacterial donor cell with A  and B  alleles. Donor cell A  B  Phage DNA

27. 2 1 Phage infects bacterial donor cell with A  and B  alleles. Phage DNA is replicated and proteins synthesized. Donor cell AA BB A  B  Phage DNA

28. 32 1 Phage infects bacterial donor cell with A  and B  alleles. Phage DNA is replicated and proteins synthesized. Fragment of DNA with A  allele is packaged within a phage capsid. Donor cell AA AA BB A  B  Phage DNA

29. 432 1 Phage infects bacterial donor cell with A  and B  alleles. Phage DNA is replicated and proteins synthesized. Fragment of DNA with A  allele is packaged within a phage capsid. Phage with A  allele infects bacterial recipient cell. Recipient cell Crossing over Donor cell A − B − AA AA AA BB A  B  Phage DNA

30. Phage infects bacterial donor cell with A  and B  alleles. Incorporation of phage DNA creates recombinant cell with genotype A  B . Phage DNA is replicated and proteins synthesized. Fragment of DNA with A  allele is packaged within a phage capsid. Phage with A  allele infects bacterial recipient cell. Recombinant cell Recipient cell Crossing over Donor cell A  B − A − B − AA AA AA BB A  B  Phage DNA 5 432 1

31. Conjugation and Plasmids  Conjugation is the process where genetic material is transferred between prokaryotic cells  In bacteria, the DNA transfer is one way  In E. coli, the donor cell attaches to a recipient by a pilus, pulls it closer, and transfers DNA

32. Sex pilus 1  m

33.  The F factor is a piece of DNA required for the production of pili  Cells containing the F plasmid (F + ) function as DNA donors during conjugation  Cells without the F factor (F – ) function as DNA recipients during conjugation  The F factor is transferable during conjugation

34. 1 One strand of F  cell plasmid DNA breaks at arrowhead. Bacterial chromosome Bacterial chromosome F plasmid Mating bridge F  cell (donor) F − cell (recipient)

35. 2 1 One strand of F  cell plasmid DNA breaks at arrowhead. Bacterial chromosome Bacterial chromosome F plasmid Mating bridge F  cell (donor) F − cell (recipient) Broken strand peels off and enters F − cell.

36. 32 1 One strand of F  cell plasmid DNA breaks at arrowhead. Bacterial chromosome Bacterial chromosome F plasmid Mating bridge F  cell (donor) F − cell (recipient) Broken strand peels off and enters F − cell. Donor and recipient cells synthesize complementary DNA strands.

37. 432 1 One strand of F  cell plasmid DNA breaks at arrowhead. Bacterial chromosome Bacterial chromosome F plasmid Mating bridge F  cell (donor) F − cell (recipient) F  cell F  cell Broken strand peels off and enters F − cell. Recipient cell is now a recombinant F  cell. Donor and recipient cells synthesize complementary DNA strands.

38.  Spore Formation  allows bacteria to remain dormant when conditions are unfavorable to reproduce  has thick internal wall that protects DNA  dehydrated form

42. Bacterial diseases: What are they and what do they affect? Gram + infections:  Streptococcus  Strep throat  Staphylococci (staph infection)

43.  Diphtheria  membrane becomes inflamed over windpipe  Botulism  Food poisoning

44.  Tetanus  caused by deep puncture wound  produces poisons and toxins which over stimulates the nervous system  causes muscle spasms  commonly known as lock jaw

45. Gram – infections  E. Coli  found in  your intestine  helps digest fat and produce vitamin K  improperly processed meat Acid Fast infections  TB –(tuberculosis)  affects the lungs

46.  Leprosy (Hansen's Bacillus)  attacks and destroys nerves  causes deformities, even loss of parts