1 gram of Hb, when fully saturated in aerial blood, carries:

Okay, let's tackle this question. The question is about how much oxygen 1 gram of hemoglobin can carry when fully saturated. Hmm, I remember that hemoglobin is the main oxygen-carrying molecule in red blood cells. Each hemoglobin molecule can bind four oxygen molecules. But wait, the question is about grams, not molecules.

Wait, I think there's a standard value here. Let me recall. I remember that hemoglobin has a high oxygen affinity. The key number I've heard before is that 1 gram of hemoglobin can carry about 1.34 mL of oxygen when fully saturated. That's a classic number in medical education. Let me verify. Yes, the oxygen-carrying capacity of hemoglobin is approximately 1.34-1.36 mL O2 per gram Hb. So the correct answer should be 1.34 mL.

Now, the options aren't listed here, but the user might have provided them in the original question. Since they're missing, I'll assume typical distractors. Let's say the options are A. 1.0 mL, B. 1.34 mL, C. 2.0 mL, D. 3.5 mL. The correct answer is B. 1.34 mL.

Why is this correct? Because each gram of Hb has four heme groups, each binding one O2 molecule. The exact value is derived from experimental data and is a standard in clinical hematology. The molecular weight of Hb is about 64,500 g/mol, and each mole of Hb binds 4 moles of O2. Using Avogadro's number and the molar volume of oxygen, the calculation arrives at ~1.34 mL/g. This is crucial for calculating oxygen content in blood, which is O2 content = Hb concentration × 1.34 × SaO2 + (0.003 × PaO2).

For the incorrect options: A. 1.0 mL is too low, maybe confusing with other values. C. 2.0 mL is higher, perhaps forgetting the exact number. D. 3.5 mL might be mixing with total oxygen content in blood, which includes dissolved O2 and Hb-bound O2.

Clinical pearl: Remembering 1.34 mL/g Hb is essential for calculating oxygen content, especially in conditions like anemia or CO poisoning where Hb function is impaired. This is a high-yield fact for exams.

**Core Concept**
This question tests the oxygen-carrying capacity of hemoglobin, a critical parameter in clinical hematology. Fully saturated hemoglobin (Hb) binds oxygen at a fixed ratio per gram, determined by its structure and molecular binding affinity.

**Why the Correct Answer is Right**
Each gram of hemoglobin can bind **1.34 mL of oxygen** when fully saturated. Hemoglobin has four heme groups per molecule, each binding one oxygen molecule. The value 1.34 mL/g is derived from the molar ratio of oxygen to hemoglobin (1 g Hb ≈ 1.34 mL O₂) and is a standard used in calculating oxygen content in blood. This value is essential for assessing oxygen delivery in conditions like anemia or hypoxia.

**Why Each Wrong Option is Incorrect**

✓ Correct Answer: B. 1.34 mL of oxygen