Name a protein which is involved in the transport of oxygen inside the human body.

Explanation

**Step-by-Step Solution:**

1. **Identify the Function of the Protein**: The question asks for a protein involved in the transport of oxygen in the human body. The primary protein responsible for this function is hemoglobin.

2. **Describe Hemoglobin**: Hemoglobin is a multi-subunit protein found in red blood cells. It consists of four subunits, which allows it to effectively bind and transport oxygen.

3. **Explain the Structure**: Each subunit of hemoglobin contains a heme group, which is a heterocyclic ring structure. This heme group contains an iron (Fe) atom at its center.

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