Mitochondria are often called the "powerhouses of the cell." They are really important because they help produce energy that our cells need.

Structure

• Number: A normal cell has between 100 and 1,000 mitochondria. This number depends on how much energy the cell needs.
• Size: Each mitochondrion is about 0.5 to 10 micrometers long, which is really small!
• Double Membrane: Mitochondria have two layers. The outer layer is smooth, while the inner layer is folded in a special way. These folds, called cristae, help make more space for the processes that create energy.

Function

1. Making ATP:

   • Mitochondria create ATP through a process called oxidative phosphorylation. This just means they take energy from food and turn it into ATP, which is the main energy source for cells.
   • When a cell breaks down one molecule of glucose (a type of sugar), it can produce about 30 to 32 ATP molecules.

2. Metabolic Pathways:

   • Mitochondria are also part of the citric acid cycle, sometimes known as the Krebs cycle. In this cycle, substances like acetyl-CoA get broken down to produce important molecules called electron carriers, known as NADH and FADH2.
   • These carriers send electrons through a series of reactions, which eventually help make ATP.

Statistics

• During aerobic respiration (when the cell uses oxygen), ATP production can provide up to 90% of a cell's energy.
• Mitochondria also help manage other processes in the cell, like breaking down fats and proteins, which shows how vital they are for energy and metabolism.