This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Which of the following is the source of nutrition for the cancer cells? \nSelect and explain. \nA. Glycolysis, B. Oxidative phosphorylation, C. Increase in mitochondria, D. From a fast food joint', 'role': 'user'}, {'content': "Answer: A \nExplanation: Cancer cells exhibit a high rate of aerobic glycolysis. Cancer cells take up large amounts of glucose and metabolize it to lactic acid, even in the presence of oxygen (the so-called Warburg effect). It is due to a defect in the respiratory chain, so that tumor cells compensated for this by producing more ATP glycolysis. Tumor cells have less mitochondria than normal cells and they contain a mitochondrial-bound isozyme of hexokinase (HK-2) that is not subject to feedback control, allowing increased uptake of glucose. Ref: Murray R.K., Jacob M., Varghese J. (2011). Chapter 55. Cancer: An Overview. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds), Harper's Illustrated Biochemistry, 29e.", 'role': 'assistant'}]