In mammalian cell culture metabolism, which pair correctly lists the principal metabolic products derived from glucose and glutamine, respectively?

Introduction / Context:
Industrial and research mammalian cell cultures (e.g., CHO, HEK293, hybridomas) exhibit characteristic carbon–nitrogen metabolism. Understanding the major by-products is critical for medium design and bioreactor control because these metabolites affect pH, osmolality, and cell viability.

Given Data / Assumptions:

• Glucose is frequently metabolized via aerobic glycolysis (Warburg-like effect).
• Glutamine is a key nitrogen and carbon source; it deaminates to produce ammonium.
• We seek the dominant measurable products in typical cultures.

Concept / Approach:
Glucose in rapidly proliferating mammalian cells often converts to lactate even in the presence of oxygen (overflow metabolism), while glutamine deamination produces ammonium (NH4+), which accumulates and can be toxic at elevated levels. Although CO2 is produced in respiration, the signature pair emphasized in bioprocess control is lactate (from glucose) and ammonium (from glutamine).

Step-by-Step Solution:

Verification / Alternative check:
Bioreactor profiles routinely monitor lactate and ammonium; feeding strategies often target lowering their accumulation (e.g., controlled glutamine feeding).

Why Other Options Are Wrong:

• A: CO2 and NH3 are produced but the primary routine pair is lactate and ammonium; NH3 exists largely as NH4+ at culture pH.
• B/D: Missing ammonium from glutamine; lactate alone is incomplete.
• E: Acetate/nitrate are not the hallmark products for these substrates in mammalian cells.

Common Pitfalls:
Ignoring ammonium toxicity; assuming strictly oxidative metabolism for glucose under all conditions.

Final Answer:
Lactate and ammonium