Metabolism and Energy Processes

Metabolism

• All living things require energy, this is called metabolism
• Metabolism is a complex of physical and chemical processes within a living cell or organism
• Essential for life's maintenance
• Some substances are broken down to produce energy for vital functions
• Other substances are synthesized requiring energy
• The first law of thermodynamics states that energy cannot be created nor destroyed but only changed
• Photosynthesis and cellular respiration are two vital reactions with energy capture and conversion in the biosphere

Photosynthesis

• Plants and some other organisms capture sunlight energy to produce sugars (glucose)
• These organisms use sunlight, water, and carbon dioxide to produce glucose and oxygen
• Photosynthesis equation: Sunlight energy + 6H₂O + 6CO₂ → C₆H₁₂O₆ + 6O₂

Cellular Respiration

• Organisms take in sugars (glucose) and break them down to release energy
• This process occurs when producers make glucose during photosynthesis
• Glucose and oxygen are used to create water, carbon dioxide, and cellular energy called ATP
• Cellular respiration equation: C₆H₁₂O₆ + 6O₂ → 6H₂O + 6CO₂ + ATP

The Carbon Cycle

• Photosynthesis and respiration are fundamental to the biological carbon cycle, functioning as inverses of each other

• Photosynthesis uses CO₂ and H₂O to produce sugars (glucose) releasing oxygen into the atmosphere

• Respiration uses oxygen and sugars producing carbon dioxide and water, releasing them into the atmosphere

• These processes occur in terrestrial and aquatic ecosystems

• Decomposition by bacteria returns carbon to the soil from dead organisms

• Erosion and volcanic activity also release CO₂ to the atmosphere and oceans

• Sedimentary rocks contain carbon compounds; these compounds can be released when rock is broken down

• Human activities increase atmospheric CO₂ levels—burning fossil fuels and deforestation contribute notably

• The diagrams illustrate the carbon cycle's various pathways through various reservoirs like the atmosphere, oceans, organisms, and fossil fuels, showing how carbon is exchanged and recycled through various processes (photosynthesis, respiration, decomposition, combustion).

Explore the fundamental concepts of metabolism, including the processes of photosynthesis and cellular respiration. Understand how living organisms capture and convert energy, essential for sustaining life. Test your knowledge on the chemical reactions that enable energy transfer in the biosphere.