Which fat-soluble vitamin appears to operate as a coenzyme that modifies proteins to bind with calcium?

Vitamin K

Coenzymes are small, nonproteinaceous molecules that work with an enzyme to initiate the function of an enzyme. They cannot function on their own and require the presence of an enzyme.  An example is vitamin K, a fat-soluble vitamin that modifies protein to bind with calcium. 

brain development. a child's brain undergoes an amazing period of development from birth to three—producing more than a million neural connections each second. the development of the brain is influenced by many factors, including a child's relationships, experiences and environment.

explanation:

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.