Final answer:
The True/False question on fajita protein choice is vague without context, but typically restaurant choices can vary. In biology, the quaternary structure of a protein doesn't always reveal its full function, as it is affected by many factors.
Step-by-step explanation:
The statement in question concerning fajitas and the number of proteins one can choose is not directly related to the provided reference information. However, if we consider typical choices for fajitas in culinary terms, the option to select up to four proteins for fajitas may vary depending on the restaurant or recipe. The information provided on species coexistence, protein functions based on quaternary structure, amino acid recycling, probability, and species as important sources of protein does not offer a clear answer to the true or false question regarding fajita protein choices.
For a biology-focused response, let's address one of the provided statements:
True or False: You can tell the function of all proteins from their quaternary structure. This statement is False. While the quaternary structure of a protein can provide insights into its function, it is not always possible to determine the function of all proteins solely based on this level of structure. Proteins have complex mechanisms of action, and their function can also depend on other factors such as localization within the cell, interaction with other molecules, and post-translational modifications.