Module 3 Flashcards
Which experiment is done to figure out which nutrients are essential for plant growth and reproduction?
Hydroponics
3 main setups of Plant Nutritional Studies
- Hydroponic growth system
- Nutrient film growth system
- Aeroponic growth system
In aeroponic growth system, nutrients are supplied in the form of _______.
Mist
What is the main difference between hydroponic growth system and nutrient film growth system?
In the nutrient film growth system, the nutrient solution is recirculated and continuously flows over the roots.
T or F. Na and Si are non-essential elements for the plant growth.
True
Enumerate all macronutrients. Include non-essential nutrients.
N K Ca Mg P S Si
Note: In some sources, Fe can be either a micronutrient or a macronutrient
Enumerate all micronutrients. Include non-essential ones.
Cl Fe B Mn Na Zn Cu Ni Mo
Note: In some sources, Fe can be either a micronutrient or a macronutrient
Enumerate the 4 groups of mineral nutrients and their function
Group 1. Nutrients that are part of carbon compounds
Group 2. Nutrients that are important for energy storage or structural integrity
Group 3. Nutrients that remain in ionic form
Group 4. Nutrients that are involved in redox reactions
Group 1 minerals
N S
Group 2 minerals
P Si B
Group 3 minerals
K Ca Mg Cl Mn Na
Group 4 minerals
Fe Zn Ni Cu Mo
Required as cofactor of more than 40 enzymes. Principal cation for cell turgor and cell electroneutrality.
K
Constituent of chlorophyll molecule. Required by many enzymes involved in phosphate transfer.
Mg
Has a key role in reactions that involve ATP.
P
Contributes to cell wall mechanical properties – rigidity and elasticity.
Si
Constituent of amino acids, proteins, nucleotides, etc.
N
Complexes with constituent of cell walls. Involved in cell elongation and nucleic acid metabolism.
B
Constituent of middle lamella. Acts as second messenger in metabolic regulation.
Ca
Required for activity of some dehydrogenases, decarboxylases, kinases, and oxidases. Involved with other cation-activated enzyme and O2 evolution.
Mn
Required for photosynthetic reactions involved in O2 evolution.
Cl
Constituent of lipoic acid, glutathione, biotin, pyrophosphate, and phosphosulfate
S
Constituent of urease. Constituent of hydrogenases in N2-fixing bacteria.
Ni
Constituent of nitrogenase.
Mo
Constituent of alcohol dehydrogenase.
Zn
Constituent of cytochromes, and nonheme iron involved for N2 fixation
Fe
Component of ascorbic acid oxidase, tyrosinase, phenolase.
Cu
Similarity between Mn and Cl
Both involved in O2 evolution
What are the mobile elements?
N K Mg P Cl Na Zn Mo
What are the immobile elements?
Ca Fe Cu B S
Name ALL essential elements for plants
C H O P K N S Ca Fe Mg Mo B Cu Mn Zn
Na Co Si Cl ARE NOT included
3 zones of nutrient concentration; Graphical representation
Deficiency, adequate, toxic
Describe critical concentration.
Amount lower (or higher) than this concentration will cause nutrient deficiency (or toxicity).
3 ways of mineral uptake
Simple diffusion
Facilitated diffusion
Active uptake
Which way of uptake requires energy/ATP?
Active uptake. Because it is against the conc. gradient.
Two types of protein channels under facilitated diffusion
Carrier protein and channel protein
Differentiate the mechanism between carrier-mediated diffusion and channel-mediated diffusion.
Carrier proteins have specific binding sites where attachment to it can cause conformational change in the carrier protein. This facilitates movement of minerals.
Channel proteins, on the other hand, have gates than open and closes.
How do protein pumps work?
ATP hydrolyses and phosphorylates the protein channel to activate it.
The degree to which a soil can adsorb and exchange ions is called ______________.
Cation exchange capacity (CEC)
Root growth is favored in (acidic/neutral/basic) soils.
Acidic.
Optimal pH for root growth.
5.5 to 6.5
Explain the mechanism of plants’ cation exchange in soil.
> Soil is (-) charged and binds with (+) nutrients.
H2O and CO2 produces H2CO3 and disassociates into HCO3- and H+
H+ competes with (+) nutrients, displacing it, and allowing it for root intake
What is Apparent Free Space
Fraction of root tissue volume not separated from environment by a diffusion barrier
Constituents of AFS of the root
Cell walls and intercellular spaces (or apoplast)
AFS is accessible by _____________.
Free diffusion
Three steps of nitrogen cycle
- Ammonification
- Nitrification
- Denitrification
What is ammonification
Bacterial and fungal catabolism. Conversion of
soil organic matter –> NH4+
What is nitrification
Bacterial oxidation:
NH4+ –> NO2- and NO2- –> NO3-
Facilitated by Nitromonas sp. and Nitrobacter sp. respectively.
What is denitrification
Bacterial conversion
NO3- –> NO –> N2
Form of nitrogen assimilated by plants
NH4+ and NO3-
