Heavy metals are metals with high density, like lead, mercury, cadmium, and arsenic. While some metals like iron or zinc are essential in small amounts, heavy metals are often toxic and can harm biological systems. Here’s a explanation:
1. Binding to Proteins and Enzymes
- Heavy metals can attach to proteins and enzymes, especially at sulfur or nitrogen groups.
- This can block enzyme activity, disrupting normal biochemical reactions.
2. Disrupting Cellular Function
- Metals like cadmium and mercury can interfere with cell membranes and ion channels, affecting nutrient transport.
- They can damage mitochondria, reducing energy production in cells.
3. Generating Free Radicals
- Heavy metals can cause oxidative stress by producing reactive oxygen species (ROS).
- ROS damage DNA, proteins, and lipids, leading to cell injury or death.
4. Accumulation in Organs
- Heavy metals are often not easily removed from the body.
- They can accumulate in organs like the kidneys, liver, brain, and bones, causing long-term damage.
5. Interfering with Essential Metals
- Heavy metals can replace essential metals like zinc, calcium, or iron in enzymes or proteins.
- This leads to loss of normal function and metabolic problems.
6. Health Effects
- Lead: Affects brain development and nervous system.
- Mercury: Damages the brain, kidneys, and immune system.
- Cadmium: Affects kidneys and bones.
- Arsenic: Can cause skin lesions, cancer, and organ damage.
Summary:
Heavy metals harm biological systems by binding to proteins, disrupting enzymes, generating oxidative stress, accumulating in organs, and interfering with essential metals. Even small amounts can be toxic over time.