How plants and animals use nitrogen: Everyday examples

📚 Nitrogen's Role in Life: A Quick Study Guide

• 🌱 Nitrogen Fixation: 🦠 Conversion of atmospheric nitrogen ($N_2$) into ammonia ($NH_3$) by bacteria. This is crucial because plants can't directly use $N_2$.
• ⚡ Nitrification: 🧪 Conversion of ammonia ($NH_3$) into nitrites ($NO_2^−$) and then into nitrates ($NO_3^−$) by nitrifying bacteria. Plants absorb nitrates through their roots.
• 🌿 Assimilation: 🥬 Incorporation of nitrogen compounds (like nitrates and ammonia) into plant proteins and nucleic acids. Animals obtain nitrogen by eating plants or other animals.
• 💩 Ammonification: 🐛 Decomposition of organic matter (like dead plants and animal waste) into ammonia ($NH_3$) by decomposers. This returns nitrogen to the soil.
• 💨 Denitrification: 🦠 Conversion of nitrates ($NO_3^−$) back into atmospheric nitrogen ($N_2$) by denitrifying bacteria, completing the nitrogen cycle.
• 🧬 Importance for Plants: 💪 Nitrogen is a key component of chlorophyll, which is essential for photosynthesis. It's also vital for amino acids, proteins, and DNA.
• 🥩 Importance for Animals: 🐾 Animals require nitrogen for building proteins (muscles, enzymes) and nucleic acids (DNA, RNA). They obtain it through their diet.

🧪 Practice Quiz

1. Which process converts atmospheric nitrogen into ammonia?
   1. Nitrogen Fixation
   2. Nitrification
   3. Assimilation
   4. Denitrification
2. What form of nitrogen do plants typically absorb from the soil?
   1. Ammonia ($NH_3$)
   2. Nitrites ($NO_2^−$)
   3. Nitrates ($NO_3^−$)
   4. Atmospheric Nitrogen ($N_2$)
3. Which of the following is NOT a direct use of nitrogen by plants?
   1. Building proteins
   2. Creating chlorophyll
   3. Forming DNA
   4. Producing carbon dioxide
4. How do animals primarily obtain nitrogen?
   1. Directly from the atmosphere
   2. Through photosynthesis
   3. By consuming plants or other animals
   4. By absorbing it from the soil
5. What process returns nitrogen to the atmosphere?
   1. Ammonification
   2. Assimilation
   3. Nitrification
   4. Denitrification
6. In what organic molecule is nitrogen found within both plants and animals?
   1. Carbohydrates
   2. Lipids
   3. Proteins
   4. Sugars
7. Which bacteria converts ammonia into nitrites and nitrates?
   1. Denitrifying bacteria
   2. Nitrogen-fixing bacteria
   3. Nitrifying bacteria
   4. Decomposers