What chemical does it start with in anaerobic respiration?

The chemical that anaerobic respiration starts with depends on the specific organism and the type of anaerobic respiration that occurs. Here are some common starting chemicals for different anaerobic respiration pathways:

1. Glucose: In many organisms, anaerobic respiration begins with the breakdown of glucose, a six-carbon sugar. Glucose is broken down through a series of enzymatic reactions to produce energy in the absence of oxygen.

2. Other Sugars: Some organisms can also use other sugars as starting materials for anaerobic respiration, such as fructose, sucrose, or lactose.

3. Organic Acids: Certain bacteria and archaea can perform anaerobic respiration using organic acids as their primary substrates. Common organic acids used include lactate, pyruvate, or succinate.

4. Amino Acids: Some microorganisms can utilize amino acids as starting compounds for anaerobic respiration. The amino acids are deaminated to produce ammonia and organic acids, which can then be further metabolized.

5. Alcohols: Alcohols can also serve as electron donors in anaerobic respiration. Ethanol (ethyl alcohol), in particular, is commonly fermented by yeast and bacteria.

It's worth noting that these are just a few examples, and there are diverse variations in anaerobic respiration pathways across different microorganisms.