Rosa eats a peanut butter sandwich for lunch. Peanut butter contains a lot of protein, and bread is mostly starch. Rosa plans to go for a run later this afternoon. Rosa is breathing normally. What does she need from the food she ate and the air she breathes so that she can go on her run? How do Rosa's body systems work together to get the molecules she needs into her cells? How do hair cells use these molecules to release energy for her body to run?

What does she need from the food she ate and the air she breathes so that she can go on her run?

A. Rosa needs carbohydrates rich food (bread) to carry out her jogging activity. Protein-rich food before exercise is not recommended unless she is on a weight loss program (diet plan).

B. Rosa needs oxygen to perform aerobic respiration, which is required for maximum release of energy (36 molecules per reaction run). Anaerobic reactions yield less energy (2 molecules of ATP per reaction run) and are not recommended.

How do Rosa's body systems work together to get the molecules she needs into her cells?

Rosa's body cells need carbohydrates (glucose) and oxygen to perform aerobic respiration for the release of maximum energy. The glucose and oxygen molecules are provided to the cells via diffusion into the bloodstream. During exercise/jogging, complex molecules of carbohydrates such as starch (present in bread) are broken down into simple molecules (glucose) which are diffused into the blood. Likewise, a high amount of oxygen is provided to the body's cells via diffusion in blood, which is carried out by the faster movement of lungs and heart. The combined action results in the supply of both types of molecules to enter the cell where mitochondria use these substrates to produce energy molecules (ATPs).

How do hair cells use these molecules to release energy for her body to run?

The substrates (glucose and oxygen) enters the bloodstream and then taken up to the cell. Then they are provided to the mitochondria for the release of energy in the form of ATP. This is why mitochondria are known as the powerhouse of the cells. Within the cell, energy is released in a three-step process, i. e. glycolysis, the Krebs cycle, and oxidative phosphorylation. Here glucose reacts with oxygen. In the end, aerobic respiration per reaction run produces 36 molecules of ATP which are sufficient to meet intensive energy needs. During excrcise, the supply of oxygen and glucose is also faster due to faster lungs and heart actions.

PS: Anaerobic respiration cannot meet energy demands faster because the reaction produces only 2 ATP molecules per reaction run.