Nitrogen Cycle: Basics: Dr A Flashcards
1
Q
What are some examples of BIOLOGICAL MOLECULES that NITROGEN help make up?
A
- Nucleotides
- Amino Acids —> Therefore Protiens
- Nucleic Acids
2
Q
Where is NITROGEN PRIMARILY FOUND?
Why is it not useful in this state?
A
- As a GAS (N2) in the ATMOSPHERE
- Plants can only use it once it has been ‘FIXATED’
3
Q
What is meant by the term ‘FIXATED’?
A
- When N has been CONVERTED into AMMONIUM IONS (NH+4)
- By SPEACIALISED BACTERIA & ALGAE
4
Q
What are the 4 STAGES in the NITROGEN CYCLE?
A
- Nitrogen Fixing
- Ammonification
- Nitrification
- Denitrification
5
Q
What is the FUNCTION of NITROGEN FIXING BACTERIA?
A
- Too ‘FIXATE’ NITROGEN
- For a PLANT TO USE
6
Q
Where can NITROGEN FIXING BACTERIA LIVE?
A
- In the ROOT NODULES of vegetables
7
Q
What are SAPROBIONTS?
A
- A group of MICRO-ORGANISMS
- Which feed on DEAD MATTER & WASTE
8
Q
What are 2 TYPES of SAPROBIONTS?
A
- Bacteria
- Fungi
9
Q
What is AMMONIFICATION?
A
- The process in which SAPROBIONTS convert LARGER BIOLOGICAL MOLECULES (via EXTRACELLULAR DIGESTION
- Into NH4+ for other plants to utilise
10
Q
What is NITRIFICATION?
A
- The process in which NITRIFYING BACTERIA
- Convert NH4+ into NO3-
11
Q
What is DENITRIFICATION?
A
- The process in which DENITRIFYING BACTERIA
- Converts NO3- into N2 which can either be FIXED or RETURNED to the ATMOSPHERE
12
Q
What do PLANTS use NH4+ for?
A
- To build LARGER BIOLOGICAL MOLECULES
- Such as PROTEINS & NUCLEIC ACIDS
13
Q
Where is the MAIN SOURCE of N in the NITROGEN CYCLE?
A
The Atmosphere
14
Q
What is the DEFINITION of ASSIMILATION?
A
- A process in which PLANTS & ANIMALS incorporate the NO3- & NH4+
- Formed through N-FIXATION / NITRIFICATION
15
Q
Why do PLANTS ASSIMILATE NO3- & NH4+?
A
- To make LARGER BIOLOGICAL MOLECULES
- Such as PROTEINS & NUCLEIC ACIDS
