Cyanobacteria

Definition

Cyanobacteria, also known as blue-green algae, are a group of photosynthetic bacteria that play a crucial role in ecosystems by producing oxygen and serving as primary producers. They are unique due to their ability to perform photosynthesis similar to plants, using sunlight to convert carbon dioxide and water into glucose and oxygen, which impacts global carbon cycling and energy flow in various environments.

5 Must Know Facts For Your Next Test

1. Cyanobacteria are among the oldest living organisms on Earth, with a history that dates back over 3 billion years.
2. These organisms are capable of nitrogen fixation, allowing them to convert nitrogen gas from the atmosphere into ammonia, which can be used by plants as a nutrient.
3. Cyanobacteria contribute significantly to global oxygen production, contributing up to 30% of the Earth's oxygen supply through photosynthesis.
4. They can form symbiotic relationships with other organisms, such as lichens and corals, providing essential nutrients and aiding in the overall health of ecosystems.
5. Certain species of cyanobacteria can form harmful algal blooms in aquatic environments, leading to decreased water quality and toxicity for marine life and humans.

Review Questions

• How do cyanobacteria perform photosynthesis and what role do they play in carbon cycling?
  • Cyanobacteria perform photosynthesis by using sunlight to convert carbon dioxide and water into glucose and oxygen, similar to plants. This process not only contributes to the production of oxygen in the atmosphere but also plays a significant role in the global carbon cycle. By absorbing carbon dioxide during photosynthesis, they help regulate atmospheric CO2 levels and provide energy for various ecosystems as primary producers.
• Discuss the significance of nitrogen fixation by cyanobacteria and its impact on ecosystems.
  • Nitrogen fixation by cyanobacteria is vital for many ecosystems because it converts inert atmospheric nitrogen into ammonia, a form that can be utilized by plants. This process enriches soil fertility and supports plant growth, thereby enhancing productivity in various environments. Additionally, it facilitates nutrient cycling within ecosystems, allowing for healthier plant communities and supporting food webs.
• Evaluate the potential risks associated with harmful algal blooms caused by cyanobacteria and their broader environmental implications.
  • Harmful algal blooms caused by cyanobacteria pose significant risks to aquatic environments and human health. These blooms can produce toxins that harm marine life, disrupt local ecosystems, and contaminate drinking water supplies. The broader implications include negative effects on fisheries, tourism, and public health, as well as contributing to eutrophication processes that further degrade water quality. Understanding these risks is essential for managing water resources effectively.

Related terms

Photosynthesis:

The process by which green plants, algae, and some bacteria convert light energy into chemical energy stored in glucose, utilizing carbon dioxide and water.

Chlorophyll: A green pigment found in cyanobacteria and plants that is essential for capturing light energy during photosynthesis.

Nitrogen Fixation: The process by which certain bacteria, including cyanobacteria, convert atmospheric nitrogen into ammonia, making it accessible for use by living organisms.