A bacterium requires the amino acids, tryptophan, tyrosine, and cystine, to be present in the agar medium in order for them to grow in the lab. These amino acids would be considered

A. It kills all microbes and endospores: Pasteurization does not eliminate all microbes or endospores; it reduces microbial load but is not a sterilization process.

B. It inactivates viruses: Pasteurization can reduce many viral pathogens present in milk, but the main purpose is to reduce bacterial pathogens and spoilage organisms.

C. It kills pathogenic microbes: Pasteurization is designed to inactivate or greatly reduce disease-causing bacteria (for example, Salmonella, Listeria, Mycobacterium) and extend shelf life.

D. It sterilizes the milk: Sterilization would remove all living organisms including endospores; standard pasteurization does not achieve sterilization.

A. Apoenzymes: Apoenzymes are the protein portion of an enzyme that require a cofactor to become active; this term describes part of an enzyme rather than its cellular location or whether it functions inside the cell.

B. Exoenzymes: Exoenzymes are secreted outside the cell to act on extracellular substrates; this term indicates extracellular action rather than intracellular function.

C. Constitutive enzymes: Constitutive enzymes are produced continuously at a fairly constant rate regardless of substrate presence; this describes regulation, not specifically intracellular location.

D. Regulated enzymes: Regulated enzymes change their level or activity in response to environmental conditions or signals; this term refers to control mechanisms rather than being intrinsically intracellular.

E. Endoenzymes: Endoenzymes function within the cell (intracellular enzymes) to catalyze metabolic reactions inside the cytoplasm or organelles.