The designated enzyme can only grow in pyruvate or in ethanol. They are said to be in anaerobic conditions. If the end product of glycolysis is pyruvate and the enzyme that transforms phosphoenol pyruvate into pyruvate is called pyruvate kinase. In a reaction under anaerobic conditions, the pyruvate is transformed into ethanol. So if the pyruvate kinase enzyme is mutated, pyruvate cannot be transformed into ethanol and Saccharomyces cerevisiae could not survive in that medium.
In the start of the light cycle, light-dependent reactions harness energy from the sun in order to create chemical bonds. These bonds are known as ATP and NADPH. These are the molecules that carry energy which are made in the stroma. The stroma is where the Calvin cycle takes place.