Nutrition in Bacteria (Leaving Cert Biology): Revision Notes
📚 Revision Notes
Nutrition in Bacteria
Bacteria can be autotrophic or heterotrophic.
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Autotrophic: organisms that produce their own food e.g. plants produce their food through photosynthesis.
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Heterotrophic: organisms that cannot make food and must use food made by other organisms, e.g. animals, fungi.
Autotrophic Bacteria
Autotrophic bacteria produce their own food.
- Photosynthetic bacteria:
- Some bacteria have chlorophyll on their membranes (no chloroplasts).
- They use light to produce food.
- Example: purple sulphur bacteria.
- Chemosynthetic bacteria
- These bacteria produce food using energy from chemical reactions.
- Example: nitrifying bacteria, which convert ammonia to nitrates during the nitrogen cycle.
Heterotrophic Bacteria
Heterotrophic bacteria cannot make their own food and must obtain it from other sources.
- Saprophytes:
- These bacteria feed on dead organisms.
- Example: bacteria of decay in the soil.
- Parasites:
- These bacteria live in or on another organism and cause harm.
- Example: streptococcus.
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Parasite: an organism that takes food from another living thing, called a host and usually causes harm.