Plant Nutrition Flashcards
Requirements for photosynthesis
- sunlight
- carbon dioxide
- chlorophyll
What is chlorophyll?
- a green chemical containing magnesium
- found inside chloroplasts
- taps sunlight to be used in photosynthesis
Define photosynthesis
- converts light energy to chemical energy
- used to build large glucose molecules from small molecules around the plants
Why is glucose converted to starch in plants?
Because it is soluble, it is easily broken down, and it increases the concentration of cytoplasm in cells, thereby slowing down enzymes. So it is generally converted to starch, which is insoluble.
Storage of energy in plants
Starch is first stored in chloroplasts in the photosynthesising cells, then converted to sucrose to be carried to the storage organs of a plant.
Define translocation (in plants)
The movement of materials from leaves to other tissues throughout the plant.
Importance of photosynthesis
- almost all known biological organisms rely on chemical energy found in carbohydrates (the product of photosynthesis)
side note: the carbohydrates may be converted to proteins/fats before being passed on - the oxygen produced by photosynthesis is essential for aerobic respiration, which occurs in most life-forms
Limiting factors of photosynthesis
- light intensity
- carbon dioxide concentration
- temperature
How factors are controlled in glasshouses:
- CO2 conc: paraffin is burnt to increase CO2 concentration up to 3x, thereby doubling yield
- temperature: thermostatically controlled heaters maintain the temp
- light: the correct wavelengths and duration controls production of fruit
Why is nitrogen necessary in plants?
- needed for protein synthesis
Symptoms of nitrogen deficiency in plants
- stunted growth
- pale leaves
- bottom leaves typically dead
Why is magnesium necessary in plants?
- needed for chlorophyll synthesis
Symptoms of magnesium deficiency in plants
- yellow leaves
- plants lacking in chlorophyll
