Question
NITROGEN METABOLISM
1. What is the percent by volume of nitrogen gas in the atmosphere?
2. Name two biomolecules that contain nitrogen in plants.
3. Why nitrogen is a stable molecule?
4. What is the percentage of nitrogen in protein?
Nitrogen fixation – Biological and Abiological?
1. What is the percent by volume of nitrogen gas in the atmosphere?
2. Name two biomolecules that contain nitrogen in plants.
3. Why nitrogen is a stable molecule?
4. What is the percentage of nitrogen in protein?
1. Which Gymnospermous plant fixes nitrogen?
2. Is there any other gas evolved during nitrogen fixation? If yes, name the gas evolved.
3. How many ATP molecules are required to reduce a single molecule of nitrogen?
4. What is the major source of electrons for reduction of nitrogen?
Which is the most reduced form of inorganic nitrogen?
2. In which part of the cell, reduction of nitrate to nitrite occurs
3. Which is the most oxidized form of inorganic nitrogen?
4. In which plant organelle reduction of nitrite to ammonia is catalysed by the
enzyme nitrite reductase?
5. Name two biochemical reactions for biosynthesis of amino acids in plants.
6. Which group of enzymes catalyses transamination reaction?
7. What is the source of amino group for amino acid synthesis in reductive
8. amination reaction?
9. Which keto acid is the source for synthesis of glutamic acid?
1. What is the percent by volume of nitrogen gas in the atmosphere?
2. Name two biomolecules that contain nitrogen in plants.
3. Why nitrogen is a stable molecule?
4. What is the percentage of nitrogen in protein?
Nitrogen fixation – Biological and Abiological?
1. What is the percent by volume of nitrogen gas in the atmosphere?
2. Name two biomolecules that contain nitrogen in plants.
3. Why nitrogen is a stable molecule?
4. What is the percentage of nitrogen in protein?
1. Which Gymnospermous plant fixes nitrogen?
2. Is there any other gas evolved during nitrogen fixation? If yes, name the gas evolved.
3. How many ATP molecules are required to reduce a single molecule of nitrogen?
4. What is the major source of electrons for reduction of nitrogen?
Which is the most reduced form of inorganic nitrogen?
2. In which part of the cell, reduction of nitrate to nitrite occurs
3. Which is the most oxidized form of inorganic nitrogen?
4. In which plant organelle reduction of nitrite to ammonia is catalysed by the
enzyme nitrite reductase?
5. Name two biochemical reactions for biosynthesis of amino acids in plants.
6. Which group of enzymes catalyses transamination reaction?
7. What is the source of amino group for amino acid synthesis in reductive
8. amination reaction?
9. Which keto acid is the source for synthesis of glutamic acid?
Answers
GPT-4o mini
### Nitrogen Metabolism
1. **What is the percent by volume of nitrogen gas in the atmosphere?**
- About 78% by volume of nitrogen gas (N₂) is present in the Earth's atmosphere.
2. **Name two biomolecules that contain nitrogen in plants.**
- Proteins and nucleic acids (such as DNA and RNA) contain nitrogen in plants.
3. **Why nitrogen is a stable molecule?**
- Nitrogen (N₂) is a diatomic molecule with a strong triple bond (consisting of one sigma bond and two pi bonds) between the two nitrogen atoms, which requires a significant amount of energy to break. This makes N₂ relatively inert and stable under normal conditions.
4. **What is the percentage of nitrogen in protein?**
- Proteins typically contain about 16% nitrogen by weight, though this can vary depending on the specific protein.
### Nitrogen Fixation
1. **Which Gymnospermous plant fixes nitrogen?**
- Some species of the genera *Ephedra* and *Gnetum* within the Gnetophyta group can fix nitrogen, though this is less common compared to angiosperms.
2. **Is there any other gas evolved during nitrogen fixation? If yes, name the gas evolved.**
- Yes, during the process of nitrogen fixation, hydrogen gas (H₂) is often evolved as a byproduct.
3. **How many ATP molecules are required to reduce a single molecule of nitrogen?**
- It requires 16 ATP molecules to reduce a single molecule of nitrogen (N₂) to ammonia (NH₃).
4. **What is the major source of electrons for the reduction of nitrogen?**
- The major source of electrons for the reduction of nitrogen is ferredoxin, which is reduced by photosystem I in photosynthetic organisms.
5. **Which is the most reduced form of inorganic nitrogen?**
- The most reduced form of inorganic nitrogen is ammonia (NH₃).
6. **In which part of the cell does the reduction of nitrate to nitrite occur?**
- The reduction of nitrate (NO₃⁻) to nitrite (NO₂⁻) occurs in the cytoplasm of plant cells.
7. **Which is the most oxidized form of inorganic nitrogen?**
- The most oxidized form of inorganic nitrogen is nitrate (NO₃⁻).
8. **In which plant organelle is the reduction of nitrite to ammonia catalyzed by the enzyme nitrite reductase?**
- The reduction of nitrite to ammonia is catalyzed by nitrite reductase primarily in the chloroplasts.
9. **Name two biochemical reactions for the biosynthesis of amino acids in plants.**
- **Transamination:** The transfer of an amino group from an amino acid to a keto acid.
- **Reductive amination:** The reaction of a keto acid with ammonia or an amine, producing an amino acid.
10. **Which group of enzymes catalyzes transamination reactions?**
- Transaminases (or aminotransferases) catalyze transamination reactions.
11. **What is the source of the amino group for amino acid synthesis in reductive amination reactions?**
- The source of the amino group in reductive amination reactions is ammonia (NH₃) or an amine.
12. **Which keto acid is the source for the synthesis of glutamic acid?**
- α-Ketoglutarate is the keto acid that serves as the source for the synthesis of glutamic acid.
1. **What is the percent by volume of nitrogen gas in the atmosphere?**
- About 78% by volume of nitrogen gas (N₂) is present in the Earth's atmosphere.
2. **Name two biomolecules that contain nitrogen in plants.**
- Proteins and nucleic acids (such as DNA and RNA) contain nitrogen in plants.
3. **Why nitrogen is a stable molecule?**
- Nitrogen (N₂) is a diatomic molecule with a strong triple bond (consisting of one sigma bond and two pi bonds) between the two nitrogen atoms, which requires a significant amount of energy to break. This makes N₂ relatively inert and stable under normal conditions.
4. **What is the percentage of nitrogen in protein?**
- Proteins typically contain about 16% nitrogen by weight, though this can vary depending on the specific protein.
### Nitrogen Fixation
1. **Which Gymnospermous plant fixes nitrogen?**
- Some species of the genera *Ephedra* and *Gnetum* within the Gnetophyta group can fix nitrogen, though this is less common compared to angiosperms.
2. **Is there any other gas evolved during nitrogen fixation? If yes, name the gas evolved.**
- Yes, during the process of nitrogen fixation, hydrogen gas (H₂) is often evolved as a byproduct.
3. **How many ATP molecules are required to reduce a single molecule of nitrogen?**
- It requires 16 ATP molecules to reduce a single molecule of nitrogen (N₂) to ammonia (NH₃).
4. **What is the major source of electrons for the reduction of nitrogen?**
- The major source of electrons for the reduction of nitrogen is ferredoxin, which is reduced by photosystem I in photosynthetic organisms.
5. **Which is the most reduced form of inorganic nitrogen?**
- The most reduced form of inorganic nitrogen is ammonia (NH₃).
6. **In which part of the cell does the reduction of nitrate to nitrite occur?**
- The reduction of nitrate (NO₃⁻) to nitrite (NO₂⁻) occurs in the cytoplasm of plant cells.
7. **Which is the most oxidized form of inorganic nitrogen?**
- The most oxidized form of inorganic nitrogen is nitrate (NO₃⁻).
8. **In which plant organelle is the reduction of nitrite to ammonia catalyzed by the enzyme nitrite reductase?**
- The reduction of nitrite to ammonia is catalyzed by nitrite reductase primarily in the chloroplasts.
9. **Name two biochemical reactions for the biosynthesis of amino acids in plants.**
- **Transamination:** The transfer of an amino group from an amino acid to a keto acid.
- **Reductive amination:** The reaction of a keto acid with ammonia or an amine, producing an amino acid.
10. **Which group of enzymes catalyzes transamination reactions?**
- Transaminases (or aminotransferases) catalyze transamination reactions.
11. **What is the source of the amino group for amino acid synthesis in reductive amination reactions?**
- The source of the amino group in reductive amination reactions is ammonia (NH₃) or an amine.
12. **Which keto acid is the source for the synthesis of glutamic acid?**
- α-Ketoglutarate is the keto acid that serves as the source for the synthesis of glutamic acid.