Intro cycles: carbon

Carbon Cycle Overview

• The carbon cycle is crucial for the sustenance of life on Earth, comprising various processes that involve carbon.

  • It makes up 96.2% of the human body, highlighting its significance in biological systems.

  • Other components include 3.2% N2, 65% O, 18.5% C, and 9.5% He.

Importance of Carbon

• Carbon is referred to as the backbone of organic compounds due to its unique ability to form multiple bonds.

  • A carbon atom has 6 protons, indicating its atomic number.

  • It has 2 electrons filling the first shell and needs 4 electrons in its second shell to be stable.

  • Therefore, carbon can form 4 bonds with other molecules, allowing for complex organic structures.

Organic Compounds

• Carbon is a fundamental component of various organic compounds:

  • Carbohydrates

  • Lipids

  • Proteins

  • Nucleic acids

Carbon in Nature

• Carbon is present in the atmosphere, primarily as dissolved CO2 in oceans.

• Various natural processes contribute to the carbon cycle, including photosynthesis:

  • Plants absorb CO2 from the atmosphere, serving as a critical part of photosynthesis.

Carbon Cycle Processes

1. Photosynthesis

   • The formula: 6CO2 + 6H2O → C6H12O6 + 6O2

   • This process removes CO2 from the atmosphere.

2. Cellular Respiration

   • The formula: C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

   • This releases CO2 back into the atmosphere, completing the cycle.

3. Combustion

   • The burning of fossil fuels such as coal, oil, and natural gas releases CO2 into the atmosphere.

4. Erosion

   • The process of erosion involves the slow breakdown of calcium carbonate from limestone, releasing carbon back into the environment as a result of chemical and physical weathering.