Nitrogen cycle |Our Ecosystem(Part-1) | Science | Grade-7,8 | TutWay |

Introduction to Matter Cycles00:00:00

The video introduces the concept of matter cycles, explaining that Earth is a closed system where matter like water, oxygen, and nitrogen remains constant because it is recycled through various processes rather than leaving the atmosphere.

The Basics of Nitrogen00:02:00

Nitrogen is identified as the most abundant gas in the atmosphere at 78%. It exists as N2 gas with a strong bond between atoms, making it unusable by most living organisms until it is broken down through fixation.

Nitrogen Fixation Processes00:03:00

The video details three ways nitrogen fixation occurs: industrial fixation using high pressure and heat, atmospheric fixation via lightning, and biological fixation by nitrogen-fixing bacteria in the root nodules of leguminous plants.

Nitrification and Assimilation00:05:00

This section explains how ammonia is converted into nitrites and then nitrates by nitrifying bacteria. Plants absorb these nitrates through assimilation to create amino acids, nucleic acids, and chlorophyll, which then move up the food chain to animals.

Denitrification and Key Processes00:09:00

The video concludes with denitrification, where bacteria convert nitrates back into nitrogen gas to return it to the atmosphere. It summarizes the four main processes: fixation, ammonification, nitrification, assimilation, and denitrification.