Term
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Definition
| single celled organism lacking a nucleus |
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Term
| Describe the size and shape of bacteria |
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Definition
| Bacterial cells are typically rod-shaped (a.k.a. ‘bacilli’) or spherical (‘cocci’), with a size of 2 - 5 µm but other morphologies occur (e.g. spirochaete = spiral; vibrio = ‘comma’-shaped) |
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Term
| State and expand upon the essential components of a bacterium. |
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Definition
-Nuclear body – a single circular chromosome encoding ~ 2 000 genes
-Cytoplasm – site of metabolic activity containing enzymes, ribosomes etc.
-Protoplast or cell membrane – major barrier between the cell and its environment
-Cell wall – contains peptidoglycan, conferring shape and osmotic protection |
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Term
describe the structures in a bacterium found in some species and not others, or found only in certain growth
conditions |
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Definition
-Granules – storage polymers made of polyphosphate or glycogen
-Photosynthetic membrane. site of photosynthesis in certain bacteria
Capsule – polymer of sugars and or amino acids surrounding the cell
Pili – protein filaments 0.1 µm long used for attachment.
-Flagellum – protein filament 3 – 20 µm long required for motility |
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Term
| How is flagellum motion driven |
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Definition
| Flagellum motion is driven by a H+ or Na+ driven rotary motor |
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Term
| Describe how bacteria and archea are able to undergo photosynthesis |
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Definition
Photosynthetic bacteria use bacteriochlorophyll to capture light energy- like in plant
chloroplasts- but photosynthetic Archaea use a light-activated proton pump called
bacteriorhodopsin |
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Term
| briefly describe bacterial population growth |
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Definition
| through binary fission, each cell divides symmetrically to form two identical daughter cells. In optimal conditions =exponential increase in cell numbers. The mean generation time = 10 min – 2 h. |
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