Bacteria Kingdoms Archaebacteria and Eubacteria

Bacteria are known in two types: Ancient Bacteria – Archaebacteria True Bacteria – Eubacteria They are considered to have been the first form of life on this planet They exist everywhere on the planet They grow in colonies All bacteria are prokaryotic – there are no membrane bound organettes

Common Characteristics: Cells are prokaryotic. All are single celled Cells contain no membrane bound organelles (like nuclei or mitochondria) Cells have a single chromosome Cells reproduce sexually by binary fission

Some bacteria are capable of locomotion by flagella

Bacteria are classified according to their shape Cossus (cocci) are round Bacillus (bacilli) are rod shaped Spirillum (spirilla) are spiral shaped

Coccus (cocci) are round

Bacillus (bacilli) are rod shaped

Spirillum (spirilla) are spiral shaped

Arrangement is then used to identify the bacteria

Bacteria are very small!!!

What would you call this?? Streptococcus bacteria: a chain of sphere shaped bacteria

What would you call this?? Streptobacilli: Chains of rod shaped bacteria

What would you call this?? Staphylococcus: A clump of sphere shaped bacteria

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Respiration Eubacteria are grouped by the type of respiration they use: 1.Some need oxygen to survive (called obligate aerobes)

2.Some can only grow where there is no oxygen (called obligate anaerobes)

3.Most can survive with or without oxygen (called facultative anaerobes)

Nutrition Most are heterotroph (get their nutrients from other organisms) Some are saprophytes (feed on dead or decaying matter) Some are autotrophs (make the food they need by photosynthesis or chemosynthesis)

Reproduction and Growth Reproduce asexually by binary fission: –Single strand DNA replicates –Identical genetic material in each new cell –Cross wall produced –Cytoplasm divides –May separate or remain attached

Binary Fission

Sexual Reproduction Does not occur in most bacteria Called conjugation –Two cells connect by a cytoplasmic bridge –One cell transfers a bit of DNA into the other –The recipient has a slightly altered characteristics

Survival Some bacteria can protect themselves from harmful environmental conditions: –Create an endospore Protects the genetic material so that when conditions are good again, the bacteria can start to re-grow