I/GCSE Biology - The carbon cycle

In I/GCSE Biology, it is important to remember the flowchart of the carbon cycle. Let's look at it in this blog post! 😽

• Fixing ➡️ Absorbing carbon dioxide from the air and converting it into complex carbon compounds
• For example:

1. Plants fix carbon dioxide during photosynthesis
2. CO₂ molecules taken into leaf - during photosynthesis changed into organic carbon compound ➡️ glucose (carbohydrate) ➡️ fixing
3. Removes carbon from physical environment
4. Glucose used for respiration ➡️ converted to CO₂ + released back into air
5. Glucose may be changed into complex carbon compounds e.g. carbs, proteins & fats in plant tissue

In I/GCSE Biology, not only do we memorise carbon fixation in plants, we also need to remember the carbon compound in animals!

• If plant eaten by animal – plant tissue broken down during digestion
• Some carbon compounds
  1. absorbed through animals gut + made into carbs, proteins, fats etc. rest ➡️ faeces
  2. converted to glucose for respiration then transformed to CO₂ – released into atmosphere
  3. become part of animals body tissues or excreted in urine – animal eaten ➡️ same processes happen in that animal
• Plant or animal not eaten ➡️ die and detritus feeders will feed on dead body
• Detritus feeder ➡️ an organism that feeds on detritus (decomposing organic waste)
  1. Break down complex carbon compounds + use them to make more carbon compounds in their bodies – release carbon as CO₂ to air from respiration
• Decomposer organism e.g. fungi + Bacteria continue process of decay – do the same as arrow above

It's very crucial of remembering the full carbon cycle in I/GCSE Biology!

• Heat + pressure turns large quantities if organisms e.g. trees into fossil fuels
• Combustion of fossil releases CO₂ into air
• When carbon returned, leaf captures it and fixes it in photosynthesis – cycle starts again
• Constant cycling of carbon through carbon compounds in living organisms + CO₂ in air ➡️ carbon cycle
• Carbon cycle ➡️ the way in which carbon atoms circulate between living organisms and the physical environment
• Only nutrients and CO₂ continuously cycled

1.  energy is captured by plants then transferred as heat to environment
2.  energy can't be used by living organisms ➡️ no energy cycle

• Plants photosynthesise during day, take CO₂ from atmosphere. Plants respire all the time releasing CO₂ back into atmosphere

References:

1. "Photosynthesis", https://cdn2.momjunction.com/wp-content/uploads/2021/04/Photosynthesis-For-Kids-Definition-Process-Diagram-And-Facts-web.jpg
2. "Carbon Compounds", https://ib.bioninja.com.au/_Media/carbon-organic_med.jpeg
3. "Carbon cycle", https://lh6.googleusercontent.com/proxy/OQ3SwLxlNsBFH9n0jcVRXLKYwz8fdBRiZtVPFPyW6WnMdNNHXFpcWZAnkLyO0a6WYvymj9sGeod3IT_GJAPuQq--StEj0st-7T9Jl0aaKJ5uUE8wbbazXcY=w1200-h630-p-k-no-nu

And we're done with this topic! Well Done!

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Drafted by Alyssa (Biology)