Siddharth Nair
10 C
BIOLOGY LAB REPORT- EFFECT ON PLANT GROWTH WITH DIFFERENT INORGANIC ION SOLUTIONS
Aim:
To investigate the effect of different inorganic ions in the form of weak solutions on germinating cress plants.
Theory:
Photosynthesis is the conversion of into by living . The raw materials are and ; the energy source is ; and the end-products are and (energy rich) , for example , and . This process is arguably the most important , since nearly all life depends on it. It is a complex process occurring in higher , , , as well as such as . Photosynthetic organisms are also referred to as . The word comes from the photo-, "light", and synthesis, "putting together".
Photosynthesis uses light energy and carbon dioxide to make
A commonly used but slightly simplified for photosynthesis is:
6 CO2(gas) + 12 H2O(liquid) + → (aqueous) + 6 O2(gas)
carbon dioxide + water + light energy → + oxygen
When written as a word equation the light energy appears above the arrow as it is required for photosynthesis but it is not actually a reactant. Here the is shown as a product, although the actual processes in plants produce disaccharides.
The equation is often presented in introductory chemistry texts in an even more simplified form as:
6 CO2(gas) + 6 H2O(liquid) + → C6H12O6(aqueous) + 6 O2(gas)
Therefore, for the following experiment, we will see the effect of nitrates, phosphates and potassium ions in the form of weak mineral solutions on the growth of a plant. The nitrates are needed for the synthesis of amino acids, proteins, chlorophyll and nucleic acids. Phosphates are taken from the soil and are necessary for making ATP, DNA and RNA which are substances that store the plant energy. They are also needed for making phospholipids or membranes. Lastly, potassium ions enable homeostasis in the plants and cause the shrinking and swelling of plant cells. They are also required for the transfer of minerals through the cell membranes of plants.
In this experiment four dilute solutions of different nitrates will be added to the cress seeds which are Sodium Nitrate, Potassium nitrate, Sodium phosphate and Potassium phosphate. They are needed in very small quantities by the plant and are thus used in 0.5 molar solutions.
Hydroponics is done without the use of any soil and it is tested on cress seeds that germinate with the nutrition supplied by the inorganic ions, water and the carbon-dioxide present in the surrounding atmosphere. These important substances will be the basis of my experiment based on the study of hydroponics.