Cancer cells derive nutrition from :
**Core Concept**
Cancer cells exhibit altered metabolism, characterized by increased glucose uptake and glycolysis, even in the presence of sufficient oxygen. This phenomenon is known as the Warburg effect, which allows cancer cells to meet their high energy demands.
**Why the Correct Answer is Right**
The correct answer is related to the Warburg effect, where cancer cells preferentially utilize glycolysis for energy production, resulting in the production of lactate. This process is mediated by the enzyme hexokinase, which phosphorylates glucose to glucose-6-phosphate, and the enzyme pyruvate kinase, which converts phosphoenolpyruvate to pyruvate. The pyruvate is then converted to lactate by lactate dehydrogenase.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because cancer cells do not primarily utilize fatty acid oxidation for energy production, unlike normal cells.
* **Option B:** This option is incorrect because cancer cells do not rely on the citric acid cycle (Krebs cycle) for energy production to the same extent as normal cells.
* **Option C:** This option is incorrect because while cancer cells do have increased amino acid metabolism, they do not derive their primary nutrition from proteins.
**Clinical Pearl / High-Yield Fact**
The Warburg effect is a hallmark of cancer metabolism, and targeting this pathway has been a focus of cancer therapy research.
**Correct Answer: A. Glucose.**