Question

Assuming that an animal uses a catabolic pathway that produces organic products, such as lactic acid or propionic acid, compare the pros and cons of retaining or excreting the organic molecules.

Short answer

Retention of catabolic by-products such as lactic acid or propionic acid offers the advantage of providing additional energy sources but poses risks such as acidosis from excessive accumulation. On the other hand, excretion of these substances helps to maintain pH balance but involves loss of potential energy sources and requires energy and resources for detoxification and excretion.

Step-by-step solution

Understanding the Catabolic Pathway

Catabolic pathways are sets of reactions that break down biomolecules, thereby releasing energy. Released energy is used in performing various body functions. Lactic acid and propionic acid are by-products of certain catabolic processes.

Pros and Cons of Retaining the Organic Molecules

Pros of Retaining- Biomolecules like lactic acid and propionic acid can be reused in anaerobic respiration and fermentation respectively. This could provide an additional source of energy for the animal's body. Cons of Retaining- Excessive accumulation of these substances may alter the body's pH, causing acidosis, which can affect protein structure and function and could be fatal.

Pros and Cons of Excreting the Organic Molecules

Pros of Excreting- Excreting these biomolecules helps to maintain a healthy pH balance in the body, thus preventing the risk of acidosis. Cons of Excreting- Energy and resources are used in the process of detoxification and excretion of these substances. This could represent a loss of potential energy resources for the animal.