Biochemistry The 40 nm gap in between the tropocollagen molecule in collagen which serves as the site of bone formation is occupied by which of the following A Carbohydrate B Ligand moiety C Ca++ D Fe++ 💡 Explanation The 40 nm gap in between the tropocollagen molecule in collagen which serves as the site of bone formation is occupied by which of the following ✓ Correct Answer: C. Ca++