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 causes more release of insulin
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Osteocalcin, secreted by osteoblasts, stimulates the beta cells in the pancreas to release more insulin. This creates a positive feedback loop as the increased levels of insulin further promote the secretion of osteocalcin.
Step 2
More insulin causes more (inactive) osteocalcin release
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
As the insulin level rises, it encourages more osteocalcin to be secreted in its inactive form. This enhances the initial stimulus, thereby reinforcing the cycle of positive feedback.
