Yeast is a facultative anaerobe. This means that alcohol fermentation takes place only if:

1 the temperature is close to 37°C
2 the atmosphere does not contain oxygen
3 sugar is provided to the cells
4 light is provided to the cells

2 the atmosphere does not contain oxygen

Explanation:

The yeast is a faculties anaerobe in that in the absence of oxygen, it is able to alter its metabolism for growth using alcoholic fermentation and also experience better growth in the presence of oxygen. They can grow both in the presence and absence of oxygen

i would say the prokaryotic cells the prokaryotic cells are less complex, are usually found only in unicellular organisms and have more limited capabilities than eukaryotic cells.

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme