How is chemical bonding used by organisms?
It is used to create new substances and for just about all processes that occur!
The most common example of chemical bonding in organisms is respiration - a process that occurs in the mitochondria of all living cells. In this reaction, glucose and oxygen react to produce water, carbon dioxide and energy. It is in effect the combustion of glucose, and due to its exothermic nature (releases energy) we can use it to fuel our bodies
However, pretty much everything that goes in in your body is caused by some some of chemical reaction - and therefore involves chemical bonding. Proteins carry out many essential processes in the body, and they are formed through the chemical bonding of amino acids (with the help of enzymes - which are basically biological catalysts).
Digestion is another example, however this is not necessarily chemical bonding, but instead breaks chemical bonds. Kong chain carbohydrates are broken up into simple sugars, like glucose, by enzymes so that they can be used by organisms for energy.
As there is chemical bonding involved in making any new substances, it is safe to say that it is used a lot by organisms. The collective term for all these reactions is your metabolism.
Hope this helps, let me know if you need any more information or something explaining more.