Most enzymes are proteins that act as biological catalysts in living organisms. They speed up chemical reactions necessary for digestion, metabolism, respiration, and many other cellular activities without being consumed themselves.

The smooth endoplasmic reticulum (SER) is responsible for the synthesis of lipids, including fats and steroids. It also helps in detoxification processes and calcium storage, especially in liver and muscle cells.

In petroleum refineries, crude oil is typically heated to around 400°C before entering the fractional distillation column. Heating separates hydrocarbons into products such as petrol, diesel, kerosene, and lubricating oils based on boiling points.

Producers such as green plants absorb usable nitrogen compounds from the soil, including ammonia (NH₃) and nitrates. Nitrogen is essential for making proteins, chlorophyll, and nucleic acids necessary for plant growth and ecosystem balance.

A camera lens forms a real, inverted, and usually diminished image on the film or image sensor. The lens focuses incoming light rays onto a surface, allowing the captured image to be recorded accurately for photography or digital imaging.