Plz help me?

The cook should compare 3 and 4.

Yeast is an unicellular fungi whose scientific name is Saccharomyces cerevisiae. This organism is an anaerobic fungi which performs alcoholic fermentation. The alcoholic fermentation is done by the enzyme zymase which is a mixture of different enzymes. This enzymes acts on glucose to form the ethyl alcohol and carbon dioxide from glucose.

Glucose - > 2 Ethanol + 2CO2.

In an open system, the carbon dioxide will evolve as gas and leave the system. So in the container with yeast, the container will loose weight but the other one won't loose any weight.