Some amount of energy is generatred from the oxidation of food materials is released as heat. This can be proved by germinating seeds.
Aim: To show that heat is liberated during respiration.
Apparatus: 2 thermos flasks, 2 thermometers, 2 rubber stoppers,2 beakers with seeds like beans or peas.

Procedure: Take 2 beakers with seeds. To one of the beakers add water and allow the seeds soak for the whole night. On the next day morning take two wide mouthed thermos flasks which can be closed with a tight fitting cork. Put the germinating seeds into one of the thermosflasks and dry seeds in another thermos flask. Make a hole in the cork and insert a thermometer into cork and see the bulb of the thermometer is in the midst of the seeds. Record the temperature in both the flasks at every two or three hour intervals for about 24H.

Observation: The temperature in the flask with germinating seeds is higher than the temperature of the flask with dry deeds. 

Inference: In dry seeds, enzymes are inactive so respiration did not take place and no rise in temperature where as in germinating seeds enzymes are active and respiration has taken place with rise in temperature.