Problem 10 - Biology the Easy Way (E-Z Biology)

Question

Nitrifying bacteria (a) convert ammonia into nitrates (b) convert ammonia into nitrogen gas (c) release ammonia from decaying bodies (d) synthesize legumes

Step-by-Step Solution

Answer

Option (a): Convert ammonia into nitrates.

Step 1: Understanding Nitrifying Bacteria

Nitrifying bacteria are a group of microorganisms involved in the nitrogen cycle. Their primary role is to convert ammonia into nitrates, a process essential for soil fertility.

Step 1: Identify the Role of Nitrifying Bacteria

Nitrifying bacteria operate in two main steps: first, they convert ammonia ( ext{NH}_3) to nitrites ( ext{NO}_2^-), primarily by bacteria such as Nitrosomonas; then, they convert nitrites to nitrates ( ext{NO}_3^-), done by bacteria like Nitrobacter.

Step 2: Evaluate Each Option in the Question

Option (a) states that nitrifying bacteria convert ammonia into nitrates, which matches the known function of these bacteria. Option (b) suggests converting ammonia into nitrogen gas, which is not a function of nitrifying bacteria. Option (c) implies releasing ammonia from decaying bodies; however, this is the role of decomposing bacteria. Lastly, option (d) states synthesizing legumes, which involves nitrogen-fixing bacteria, not nitrifying ones.

Step 3: Conclusion

Based on the evaluation, the role of nitrifying bacteria corresponds to option (a): they convert ammonia into nitrates.

Key Concepts

Nitrogen Cycle

The nitrogen cycle is a fundamental process in nature that ensures the continuous flow and transformation of nitrogen through the environment. Nitrogen is a vital element found in amino acids and proteins, making it essential for all living organisms. However, most nitrogen in the atmosphere exists as \( \text{N}_2 \), which is not readily accessible to most plants or animals.
Nitrifying bacteria play a critical role in the nitrogen cycle. They assist in transforming ammonia, produced from the waste or decay of organic matter, into nitrites and then nitrates. These conversions are crucial since nitrates are a form of nitrogen that plants can absorb and utilize. This natural recycling process ensures that the nitrogen content in the soil remains balanced, supporting plant growth and ecosystem health.
It's important to understand that nitrifying bacteria are just one part of a broader system. Other participants include nitrogen-fixing bacteria that convert atmospheric nitrogen into ammonia, as well as denitrifying bacteria that restore \( \text{N}_2 \) to the atmosphere. Together, these interactions maintain the nitrogen balance needed for life.

Soil Fertility

Soil fertility is determined by the availability of nutrients that plants require to grow successfully. Among these nutrients, nitrogen holds a significant place, as it is a building block of proteins and essential for photosynthesis.
Nitrifying bacteria enhance soil fertility by converting ammonia into nitrates, a nitrogen form easily taken up by plants. This process, known as nitrification, helps maintain an optimal nutrient balance in the soil.

• This allows plants to grow more robustly and produce better yields.
• Healthy plant growth contributes to a thriving ecosystem, ensuring that other organisms dependent on plants have adequate resources.

Managing soil fertility often involves ensuring that nitrifying bacteria are present and active in the soil. Farmers and gardeners might employ practices such as organic composting or crop rotation to support these microorganisms. These practices not only support soil health but also promote sustainable land management practices.

Ammonia Conversion

Ammonia conversion is the process through which ammonia \( (\text{NH}_3) \) is transformed into other nitrogenous compounds, primarily nitrites \( (\text{NO}_2^-) \) and nitrates \( (\text{NO}_3^-) \), by nitrifying bacteria. This conversion plays a key role in making nitrogen available to plants.
The conversion occurs in two main stages:

• The first stage involves bacteria such as Nitrosomonas, which oxidize ammonia into nitrite.
• In the second stage, the nitrite is further oxidized to nitrate by bacteria like Nitrobacter.

These processes require specific environmental conditions, such as ample oxygen and appropriate pH levels, to occur efficiently. By enabling nitrate production from ammonia, nitrifying bacteria help increase the nitrogen content in soils, thus boosting the nutrient availability essential for plant growth.
Ammonia conversion is vital for managing waste products as well. By transforming potential toxins into valuable nutrients, this process minimizes harmful effects on the environment. Understanding ammonia conversion helps in developing agricultural and waste management practices that are more environmentally friendly.