the sugar. The same type of smell you can notice from preserved idly, dosa dough at your home. But not in refrigirator. The ethanol can be separated from the yeast-glucose mixture by the process of fractional distillation since ethanol boils at a lower temperature (70C) than the sugar solution. Collect information about fractional distillation with the help your teacher.

Quite like aerobic respiration this is a process of producing energy when there is no supply of oxygen.

Respiration is an energy releasing pathway, do you agree? Justify your answer.

Lavoisier around the late 18thcentury, through a series of carefully performed experiments, came to the opinion that respiration was a process like combustion. He wrote in a compilation in 1783, "respiration is a combustion process. It is a very slow process and here oxygen is not only combines with carbon but also with hydrogen." Robinson also stated that respiration is a type of combustion and combustion is the source of heat in animals

Activity-2

Arrange apparatus as shown in the figure and heat it over a flame. Does it melt? What happens if you heat for somemore time?

When glucose burns, carbon dioxide and water are produced and energy is released as heat.

We know that combustion of glucose gives us carbon dioxide, water and energy while from the respiratory equation we get the same products. But essentially the processes must differ due to following reasons.

1. Glucose must be burnt at high temperature in the laboratory to liberate energy, if it happened in our cells,all cells would be burnt.

2. Once glucose starts burning we can't stop the process easily, but living cells are able to exercise control over the sort of burning of glucose in the presence of oxygen