Answer:
The cells lying in the deeper layer of periosteum are known as osteoblasts (bone forming cells). These cells divide continuously and form the osteocytes, thus increase the thickness of bone. ... The process of reshaping the bone is called <u>remodeling </u>and it is one of the major factors responsible for increasing size of marrow cavity.
All mentioned complexes (receptor-hormone, antibody-antigen, enzyme-substate) are involved in a molecular recognition.The molecular recognition involves <span>non-covalent </span> interaction between molecules. To form complex, molecules must be complementary in shape and charges, and usually, they are compared to key and lock. This way, the selectivity and specificity of recognition between molecules are assured.