Respiratory System

Why is there life on Earth?

Why do we breathe?

To transport oxygen through blood into our muscles to burn fuel for energy/movement

Respiration

All of this energy comes from the food that we eat.
The food is digested
- i. e. broken down into smaller molecules - which are absorbed from the intestine into the blood.
The blood transports the nutrients to all the cells in the body
The cells take up the nutrients that they need.
The main nutrient used to provide energy in cells is glucose.
- It contains a lot of chemical energy
In order to make use of this energy, cells have to breakdown the glucose molecules and release the energy from them.

Note

They do this in a series of metabolic reactions called respiration.

\begin{matrix} Water = H_{2} O \\ Glucose = C_{6} H_{12} O_{6} \\ C_{6} H_{12} O_{6} + 6 O_{2} ⟶ 6 CO_{2} + 6 H_{20} + ATP (Energy) \end{matrix}