Category Nuances for heme:

• physiological,
• prosthetic,
• essential,
• biological,
• molecular,
• cellular,
• iron,
• aromatic,
• inhibitory,
• natural,
• organic,
• important,
• colored,

Simple Categories for heme:

• group,
• entity,
• component,
• substance,
• material,
• substrate,
• pigment,
• porphyrin,