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: Unknown
[{'content': 'Which one of the following about enzymes is true? \nSelect and explain. \nA. High Km-High affinity, B. Low Km-High affinity, C. Non-competitive inhibition- Decreases Km, D. Non-competitive inhibition – Increased Km', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Refer: DM Vasudevan, Textbook of Biochemistry, 7th edition, pg no: 59 - 60)\nThe Michaelis constant (km)\n\nKm provides a measure of the affinity of the enzyme for its substrate.\nIt is equal to substrate concentration at which reaction velocity is equal to ½ Vmax.\nKm = substrate concentration when reaction velocity is % Vmax.\nKm is constant for any given enzyme.\nKm is independent of substrate or enzyme concentration.\nThe higher is KM, the higher is the concentration of the substrate required to reach ½ Vmax.\nThat is: at a lower affinity, a higher concentration of substrate is required to reach ½\xa0 Vmax.\n↓ Km = ↑ affinity.', 'role': 'assistant'}]