In humans and other animals:
* Cytoplasm: The process of glycolysis, which is the first stage of both aerobic and anaerobic respiration, occurs in the cytoplasm of cells. In the absence of oxygen, pyruvate, the end product of glycolysis, is further broken down into lactate in a process called lactic acid fermentation.
In bacteria and some other microorganisms:
* Cytoplasm: Again, glycolysis happens in the cytoplasm. However, depending on the type of bacteria, the end product of anaerobic respiration can vary. For example:
* Alcoholic fermentation: Pyruvate is converted into ethanol and carbon dioxide.
* Other types of fermentation: Some bacteria use different pathways for anaerobic respiration, producing various organic acids as byproducts.
Important Note: While anaerobic respiration can happen in specific organelles within cells, it primarily occurs in the cytoplasm.
