The secretion of osteocalcin (in an inactive form) by osteoblasts is controlled by positive feedback - AQA - A-Level Biology - Question 1 - 2018 - Paper 3
Question 1
The secretion of osteocalcin (in an inactive form) by osteoblasts is controlled by positive feedback.
Use information from Figure 1 to explain why this is positive ... show full transcript
Worked Solution & Example Answer:The secretion of osteocalcin (in an inactive form) by osteoblasts is controlled by positive feedback - AQA - A-Level Biology - Question 1 - 2018 - Paper 3
Step 1
Osteocalcin secretion leads to more insulin release.
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Answer
Osteocalcin, when secreted by osteoblasts, stimulates the beta cells in the pancreas to release more insulin. This increase in insulin levels encourages further secretion of osteocalcin, initiating a positive feedback loop.
Step 2
Insulin further amplifies osteocalcin activity.
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Answer
As more insulin is released, it continues to promote the secretion of inactive osteocalcin, which then undergoes activation. This process ensures that osteocalcin's role in bone repair is consistently supported, reinforcing the cycle of positive feedback.
