The production of free radicals in cells happens through both internal (endogenous) and external (exogenous) sources. These free radicals can cause damage if they’re not balanced by antioxidants.
Endogenous Sources (Internal):
1. Mitochondrial Electron Transport Chain:
This is the main way cells produce energy through a process called aerobic respiration.
Here, oxygen is used to create energy, and electrons are passed through a series of steps.
Sometimes these electrons escape early and react with oxygen to form superoxide radicals, a type of reactive oxygen species (ROS).
2. Enzymatic Reactions:
Some enzymes in the body, like NADPH oxidase, xanthine oxidase, and lipoxygenases, naturally produce ROS while they work.
These enzymes are involved in various body functions, but sometimes they release free radicals as a side effect of their actions.
3. Immune Response:
When your body fights off infections, certain immune cells called phagocytes release ROS to kill bacteria and viruses.
This release, known as the respiratory burst, is a critical part of the body's defense system but also leads to the production of free radicals.
Exogenous Sources (External):
1. Environmental Factors:
Things like UV light from the sun, ionizing radiation (like from X-rays), pollution, and certain chemicals can create free radicals inside our bodies.
These sources can damage cells by increasing the number of harmful free radicals.
2. Diet:
Eating foods high in fats and alcohol can also lead to an increase in free radicals.
These dietary components can change how cells function and boost the production of these damaging molecules.
3. Smoking:
Cigarette smoke is packed with free radicals. When you smoke, these radicals enter your body, leading to oxidative stress and increasing the risk of various diseases by damaging cells.
Understanding both internal and external sources of free radicals helps in managing health risks and reinforces the importance of a balanced diet, avoiding harmful environmental exposures, and maintaining a healthy lifestyle to minimize damage from these reactive molecules.