Nutrient Cycles

Question 1

Biological molecules containing nitrogen

Answer 1

ATP, Nucleic acids, Proteins , Amino acids, DNA, RNA

Question 2

4 stages of the Nitrogen cycle

Answer 2

1. Nitrogen fixation
2. Ammonification
3. Nitrification
4. Denitrification

Question 3

Process of ammonification

Answer 3

Organic material is broken down by saprobiotic bacteria to release ammonium ions back to the soil.

Question 4

Process of nitrification

Answer 4

• Nitrification where nitrifying bacteria convert ammonia to nitrate ions, NO3-, in an oxidation reaction, with a nitrite ion, NO2 -, intermediate. Most plants can take in nitrate ions through their roots.

Question 5

Process of Denitrification

Answer 5

Nitrate ions (NO3–) and converted back into nitrogen gas (N2) by denitrifying bacteria.

Question 6

Process of Nitrogen Fixation

Answer 6

Nitrogen fixing bacteria convert nitrogen gas into ammonia, which forms ammonium ions (NH4+).

Question 7

What is phosphorus used for in organism

Answer 7

Acts as a backbone in DNA
ATP
Phospholipid bilayer

Question 8

Outline the role of mycorrhizae

Answer 8

Important in facilitating the uptake of water and inorganic ions by plants. They increase the surface area and act as a sponge holding water and minerals. As a
result a plant can better resist drought and take up inorganic ions more easily.