With the help of an experiment demonstrate that CO 2 is given out in breathing.

Aim: To prove that carbon dioxide is released during breathing. Requirements: Conical flask, a beaker, a cork with a hole, a glass tube bent at right angles at two places, a small test tube, KOH solution, thread, coloured water, vaseline and germinating seeds of gram or pea. Theory: Respiration is a catabolic process. In this process, the oxidation of complex organic molecules into simpler compounds with the release of energy. This process can occur aerobically and anaerobically. The reaction mechanism of aerobic respiration involves the complete oxidation of carbohydrates. C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O + Energy Diagram of the experiment: Procedure: 1. Take the conical flask and put some germinating seeds in it. 2. Insert the shorter end of the glass tube through the hole in the cork and fix it on the conical flask. 3. Hang a test tube containing KOH solution inside the conical flask with the help of a thread. 4. Take coloured water in the beaker and keep the longer end of the glass tube dipped inside it. 5. Make the conical flask airtight by applying vaseline on its rim. Now note the initial level of water in the tube. 6. Observe and note the rise in the water level after an hour, without disturbing the apparatus. Observation: Water level rises in the bent tube. Result: The rise in the level of water indicates that CO2 is produced by germinating seeds during respiration. The germinating seeds respire and produce CO2, which is absorbed by KOH solution due to this creates a vacuum in the conical flask. The air present in the bent glass tube moves into the conical flask and pulls the water in the bent tube further up.