B.11A Cyanide Why it Kills Approaching – 03

Oxygen is present in our atmosphere and comes from photosynthesis. Plants can make glucose (food) by combining carbon dioxide and water using energy from the sun.

Living things that cannot perform photosynthesis must eat other organisms for energy. Digestive systems break down food into smaller parts like glucose that can enter cells. Cellular respiration is the process that breaks down glucose to get energy for the cell.

Most cellular respiration needs oxygen. There are a series of proteins in a cell structure called the electron transport chain. The proteins in the electron transport chain move electrons from one place to another. They also transfer protons (hydrogen ions) across a membrane. The hydrogen ions (H+) will combine with oxygen, forming water as a waste product.

This process happens in the mitochondria of a cell, and when oxygen accepts these hydrogen ions, energy from this reaction makes adenosine triphosphate (ATP) which the cell uses for energy. This is why a mitochondrion is known as the “powerhouse” of a cell.

Oxygen is needed to form adenosine triphosphate (ATP). ATP is needed to do cellular processes like active transport and cell division. Without oxygen, most cells cannot get enough energy to conduct necessary tasks, and they will begin to die.