Question

Glutamine is a critically important nutrient in animal cell culture media because it primarily functions as

• A. An exclusive carbon source for ATP generation through full oxidation in mitochondria
• B. A source of nitrogen for nucleotide and non-essential amino acid biosynthesis
• C. A pH stabilizer that prevents acidification of the culture medium
• D. An attachment factor required only by adherent cells

Hint:

Glutamine is called the "fuel of rapidly dividing cells" because it provides nitrogen for nucleotide synthesis and supports rapid cell growth in tissue culture.

Answer 1

The Correct Option is B

Concept: Glutamine is one of the most important nutrients present in animal cell culture media. It serves as a major source of nitrogen and also contributes carbon skeletons for various biosynthetic pathways. Rapidly dividing cells consume glutamine at a high rate because it is required for the synthesis of proteins, amino acids and nucleotides.
• Glutamine is an amino acid essential for rapidly growing cells.
• It supplies nitrogen for the synthesis of purines and pyrimidines.
• It participates in the formation of non-essential amino acids.
• It also contributes to energy metabolism, but its major role is as a nitrogen donor.

Step 1: Understand the biological role of glutamine.
Animal cells require glutamine for the synthesis of DNA, RNA and proteins. During cell division, nitrogen is required for nucleotide synthesis, and glutamine serves as the major nitrogen donor. \[ \boxed{\text{Glutamine} \longrightarrow \text{Nitrogen source} \longrightarrow \text{Nucleotide synthesis}} \]

Step 2: Eliminate the incorrect options.

• Glutamine is not an exclusive carbon source for ATP production.
• It does not function as a pH stabilizer.
• It is not an attachment factor for adherent cells. Its primary physiological role is supplying nitrogen for various biosynthetic reactions.

Step 3: Choose the correct option.
Hence, \[ \boxed{Option (B) is the correct answer. \]