Overview

Plants, animals, and single-celled organisms such as bacteria all must harness energy to live. Each does so by breaking down food to recharge ATP (adenosine triphosphate). In plants, this process is called photosynthesis. In animals and non-plant single-celled organisms, this process is called cellular metabolism.

In cellular metabolism, the primary food molecule used is glucose, but the body utilizes all food molecules - fats, proteins, as well as carbohydrates - to create ATP. What does our body take in besides food to help produce energy? Oxygen. And wat does our body give off due from cellular metabolism? Water (H2O) and carbon dioxide (CO2).

Glucose (C₆H₁₂O₆) + 6 O₂ --> 6 H₂0 + 6 CO₂

Throughout this instruction, you will learn about the steps in cellular metabolism.

Cellular metabolism begins in the cytoplasm of cells in a process known as glycolysis. If oxygen is present, most cells will utilize aerobic respiration. This process moves to the cell's mitochondria and moves through the Kreb's cycle and then to electron transport phosphorylation. If oxygen is not present, cellular metabolism continues in the cell's cytoplasm in a process known as anaerobic respiration.