Breathing: the mechanical process of ventilation, by which air is sucked in and pushed out of our lungs.

Respiration: the biochemical process by which our bodies utilize oxygen rich air in cellular metabolism and release carbon dioxide.

Breathing is the physical act that animals perform to take in oxygen rich air and expulse oxygen deficient air. Respiration is the chemical process by which cells break down energy rich molecules (glucose) to get energy to perform cellular functions.

Breathing is voluntary while as respiration is involuntary.

-the answer may be found in science 7 books

Your Breathing rate is increased due to the fact that your muscles are working harder then when they are at rest. This means that they need oxygen, along with sugars to complete cellular respiration. Your heart rate increases so that it can move the oxygen to the target cell in the muscles you are using quicker.

His heart rate will be faster and his heart will pump to transport blood rich-in oxygen to all parts of the body

"His [Smaug's] rage passes description--the sort of rage that is only seen when rich folk that have more than they can enjoy suddenly lose something that they have long had but have never before used or wanted."