Plant Anatomy and Plant Physiology - Formula Sheet

Key Chemical Equations and Mathematical Formulas

1. Photosynthesis Equation

6CO2 + 12H2O --(Light / Chlorophyll)--> C6H12O6 + 6H2O + 6O2

• CO2: Carbon dioxide absorbed from air via stomata
• H2O: Water absorbed from soil by root hairs
• C6H12O6: Glucose synthesized as organic food
• O2: Oxygen released as a gaseous byproduct

2. Photolysis of Water

2H2O --> 4H+ + 4e- + O2

• H2O: Water molecule split in grana thylakoids by light energy
• H+: Hydrogen ions (protons) utilized for NADP reduction
• e-: Electrons replacing lost electrons in chlorophyll pigments
• O2: Molecular oxygen released into atmosphere

3. Aerobic Respiration Equation

C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATP Energy

• C6H12O6: Hexose sugar (glucose) oxidized as respiratory substrate
• O2: Molecular oxygen serving as terminal electron acceptor
• CO2: Carbon dioxide released during decarboxylation reactions
• H2O: Metabolic water formed at end of electron transport chain
• ATP: Adenosine triphosphate synthesized as cellular energy currency

4. Anaerobic Respiration (Alcoholic Fermentation)

C6H12O6 --> 2C2H5OH + 2CO2 + 2 ATP

• C6H12O6: Substrate glucose decomposed in cytoplasm without oxygen
• C2H5OH: Ethyl alcohol (ethanol) generated as end product
• CO2: Carbon dioxide evolved during anaerobic reaction
• ATP: Net cellular energy generated per glucose molecule

5. Respiratory Quotient (RQ)

RQ = (Volume of CO2 evolved) / (Volume of O2 consumed)

• RQ: Respiratory Quotient, a dimensionless ratio dependent on substrate type
• Volume of CO2 evolved: Total volume of carbon dioxide released during respiration
• Volume of O2 consumed: Total volume of oxygen utilized during substrate oxidation