1.3 Carbon Cycle

• Carbon dioxide (CO2) is released into the air when plants die or are burned. This is a result of either respiration or combustion. Respiration is the process in which the cells of an organism obtain energy by combining oxygen and glucose, resulting in the release of carbon dioxide, water, and ATP (energy). Combustion is a chemical process in which a substance reacts rapidly with oxygen and gives off heat.
• The carbon cycle involves the movement of carbon between living organisms, dead organic matter, and the atmosphere.
• Photosynthetic organisms take up CO2 from the atmosphere during photosynthesis. This affects the carbon cycle as autotrophs use carbon from the atmosphere to create oxygen.
• In the carbon cycle, when these organisms die, their remains decompose to release CO2 back into the atmosphere.
• Some of this decomposed material becomes part of sedimentary rock through processes such as compaction and cementation. This decomposed material turns into fossils which can be combusted into fossil fuels. Combustion of fossils releases carbon in the atmosphere
• Burning fossil fuels releases CO2 back into the atmosphere, contributing to global warming as there is an increase in greenhouse gases which determines the heat in the atmosphere.
• These fossil fuels contain large amounts of stored energy that can be used by humans.
• Carbon Cycle:

  • Carbon is stored in the air as carbon dioxide, in plants as biological molecules, in soil with bacteria and microorganisms, in fossil fuels underground, and in animals as biological molecules
  • Photosynthesis by green plants and algae converts carbon dioxide into glucose
  • Carbon can be released back to the atmosphere through respiration or passed on to animals
  • Dead organisms can be decayed aerobically in soil, releasing carbon dioxide, or decayed anaerobically to form fossil fuels like oil, natural gas, or coal
  • Fossil fuels can be burned by humans to produce carbon dioxide
• Decomposers break down dead plant and animal matter, releasing carbon dioxide back into the environment.
• Plants absorb carbon dioxide during photosynthesis, while animals obtain energy by consuming plants or other animals.
• It forms the basis of many molecules including carbohydrates, lipids, proteins, nucleic acids, and some vitamins.
• Humans release large amounts of carbon dioxide into the atmosphere through burning fossil fuels.
• Carbon is an essential element found in all living things.
• This has led to increased levels of atmospheric carbon dioxide, contributing to global warming.
• Carbon moves around the Earth in different ways, such as being absorbed by plants during photosynthesis, being released when plants die and decompose, and being used by animals for food.
• Animals consume plants or other animals and release carbon dioxide when they breathe out.
• Humans have disrupted the carbon cycle by burning fossil fuels, which releases large amounts of carbon dioxide into the atmosphere.
• When plants die, decomposers break them down and release carbon dioxide.
• Animals cannot make their own food so they must eat plants or other animals that have eaten plants.
• The carbon from these foods is stored in animal bodies until it is eventually returned to the environment through respiration or decomposition.
• Respiration is the process whereby cells break down glucose to produce ATP, releasing carbon dioxide and water.
• The carbon cycle involves the movement of carbon between living organisms and their environment through processes such as respiration, decomposition, and combustion.
• The carbon cycle starts with carbon dioxide in the atmosphere
• Carbon enters the carbon cycle through photosynthesis, where carbon dioxide combines with water to make the sugar glucose
• Photosynthesis is carried out by plants and uses light energy
• Carbon dioxide returns back to the atmosphere through aerobic respiration
• Every living organism carries out respiration
• Respiration and breathing are not the same thing
• The carbon cycle involves two key processes: photosynthesis and respiration
• Photosynthesis:

  • Plants and algae take in carbon dioxide from the atmosphere
  • Carbon is used to make carbohydrates, fats, and proteins in the cells of plants and algae
• Respiration:

  • Plants and algae respire, releasing some carbon back to the atmosphere as carbon dioxide
  • Animals that eat plants and algae incorporate the carbon into their cells through carbohydrates, fats, and proteins
  • Animals also respire, releasing some carbon back to the atmosphere as carbon dioxide
  • Waste products and dead remains of animals and plants are broken down by decomposing microorganisms like bacteria and fungi
• Decomposers:

  • Decomposers carry out respiration, returning the carbon in waste and dead remains back to the atmosphere as carbon dioxide
  • Decomposers cycle materials through an ecosystem and release mineral ions to the soil
• Under certain conditions, like a lack of oxygen, decomposers cannot function effectively, leading to the slow conversion of carbon in dead remains to fossil fuels
• Humans burning fossil fuels like coal and oil release a large amount of carbon dioxide back to the atmosphere
• Carbon dioxide (CO2) is the main greenhouse gas in climate change
• Carbon is part of a cycle that starts with the sun heating the Earth's surface
• Plants perform photosynthesis, taking sunlight and CO2 to create stored energy in the form of carbohydrates like glucose and sucrose
• When animals eat plants, the food is converted back into energy for growth, releasing greenhouse gases as a byproduct
• Greenhouse gases are also released through waste and decomposition of dead plants by microorganisms
• Carbon-based organisms can be compressed under pressure in the earth, turning into fossil fuels like oil, coal, or natural gas