Question

In animal cell culture, sodium bicarbote is added in culture media to:

• A. Maintain the correct pH.
• B. Maintain proper aeration.
• C. Promote the uptake of Iron in animal cells.
• D. Keep the cells adhered to the plastic.

Hint:

$\text{HCO}_3$ in media + 5% $\text{CO}_2$ gas in incubator = Bicarbote Buffer System for maintaining physiological pH ($\sim 7.4$).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the physiological function of sodium bicarbote ($\text{HCO}_3$) added to cell culture media during animal cell cultivation.

Step 2: Key Formula or Approach:
Animal cells require a strictly maintained physiological pH range ($\text{pH } 7.2 - 7.4$). This is achieved using a bicarbote-carbon dioxide buffering equilibrium: \[ \text{CO}_2 + \text{H}_2\text{O} \rightleftharpoons \text{H}_2\text{CO}_3 \rightleftharpoons \text{H}^+ + \text{HCO}_3^- \]

Step 3: Detailed Explation:

• Role of $\text{HCO_3$ as Buffer:} Dissolved sodium bicarbote provides bicarbote ions ($\text{HCO}_3^-$) in the culture medium.

• Interaction with Incubator $\text{CO_2$:} When placed in a humidified incubator containing controlled $\text{CO}_2$ gas (typically 5% $\text{CO}_2$), the dissolved $\text{CO}_2$ establishes an equilibrium with exogenous $\text{HCO}_3^-$.

• pH Stabilization: As cells release metabolic acids (like lactic acid), the equilibrium shifts to neutralize extra protons ($H^+$), maintaining stable extracellular physiological pH.

• Evaluation of Other Options: Aeration is maged by culture volume/shaking; iron uptake is promoted by transferrin; cell adherence is facilitated by extracellular matrix proteins (e.g., collagen, fibronectin).

Step 4: Fil Answer:
Sodium bicarbote is added to animal culture media primarily to maintain optimal physiological pH.