Pesticides
Chemicals that control pests but may harm ecosystems.
Practise Biochemistry, Environment & Industry All Biochemistry, Environment & Industry topics
Chemicals that control pests but may harm ecosystems.
Practise Biochemistry, Environment & Industry All Biochemistry, Environment & Industry topics
Pesticides are chemicals used to kill or control pests such as insects, fungi, weeds and rodents. Organochlorines such as DDT are persistent and fat-soluble, while organophosphates and carbamates inhibit acetylcholinesterase, causing nerve overstimulation in insects and, at high doses, in people. Pyrethroids are synthetic analogues of natural insecticides, and glyphosate is a widely used herbicide that inhibits an enzyme of the shikimate pathway. Pesticides raise crop yields but can harm non-target species, contaminate water and accumulate in food. Integrated pest management aims to reduce chemical use.
Key ideas: Classes: insecticides, herbicides, fungicides, rodenticides. Chemical families: organochlorines (DDT, persistent), organophosphates (inhibit acetylcholinesterase), carbamates, pyrethroids, neonicotinoids, glyphosate (blocks EPSP synthase). Persistence, toxicity and mobility determine impact. Integrated pest management cuts use.
Common mistakes and connections: Mistake: thinking a pesticide only affects the target; nontarget species and resistance develop. DDT was banned for agriculture after eggshell thinning in birds, though still used for malaria vectors in some places. Links to bioaccumulation, enzymes inhibition and green chemistry.
Approximate soil half-lives of pesticides. Persistent organochlorines such as DDT remain for years, while modern ones break down in days to weeks. The interactive lesson shows this as a live animation or chart.
Rachel Carson's book Silent Spring, published in 1962, highlighted the ecological damage caused by DDT.
Chemicals that control pests but may harm ecosystems.
Pesticides is a intermediate topic in Biochemistry, Environment & Industry. It builds on the vocabulary of beginner topics in this area.
Study these earlier topics in Biochemistry, Environment & Industry first: Biochemical Oxygen Demand, Dissolved Oxygen, Heavy Metal Pollution.
The next topics in Biochemistry, Environment & Industry are Bioaccumulation and Waste Management.
Yes. The interactive lesson includes a self-check question on Pesticides, and the Biochemistry, Environment & Industry quiz draws on every topic in this area.
Pesticides is topic 84 of 127 in Biochemistry, Environment & Industry.
Browse all 127 topics in Biochemistry, Environment & Industry