The answers are DNA and Nucleus
Answer:
It transport oxygen from lungs to the cells.
Explanation:
The presence of iron in our body is very important for this process because iron is responsible for the transportation of oxygen. Hemoglobin is made up of iron that takes oxygen from the lungs to each and every cell. Iron is an essential element for the formation of blood in human body. About 70 percent of body's iron is found in the red blood cells of our blood called hemoglobin and in the muscle cells called myoglobin. So we can say that iron is very important for the release of energy in the process of respiration.
Provided that there's no diagram, most molecules have particular areas on the molecules, called the "active area" that act as a lock to a particular substrate's molecular structure, providing the key.
An enzyme's active area is only able to be "unlocked" by a certain substrate's "key".
