Question

1. what roles do photosynthesis & cellular respiration play in the carbon & oxygen cycles? science 14 (sx3 - analyze and interpret) name: name

Explanation:

Photosynthesis in Carbon and Oxygen Cycles:

• Carbon Cycle: During photosynthesis, plants (and some other organisms) use carbon dioxide ($\ce{CO_2}$) from the atmosphere. The process, driven by light energy, converts $\ce{CO_2}$ and water ($\ce{H_2O}$) into glucose ($\ce{C_6H_{12}O_6}$) and oxygen ($\ce{O_2}$) via the reaction: $$\ce{6CO_2 + 6H_2O \xrightarrow[\text{Chlorophyll}]{\text{Light Energy}} C_6H_{12}O_6 + 6O_2}$$ This removes $\ce{CO_2}$ from the atmosphere and incorporates carbon into organic compounds (like glucose) in living organisms. These organic compounds can be used by the plant for growth or consumed by other organisms in the food chain. When organisms die and decompose, or when plants/animals respire (or when fossil fuels are burned), carbon is eventually released back as $\ce{CO_2}$, but photosynthesis is the primary way carbon is "fixed" (converted from inorganic to organic form) in the cycle.
• Oxygen Cycle: Photosynthesis releases oxygen ($\ce{O_2}$) as a by - product. This oxygen is released into the atmosphere and is essential for aerobic organisms (including animals, plants during respiration, and many microbes) to perform cellular respiration. The oxygen produced by photosynthesis replenishes the atmospheric oxygen that is used up in various processes like respiration and combustion.

Cellular Respiration in Carbon and Oxygen Cycles:

• Carbon Cycle: Cellular respiration is the process by which organisms (plants, animals, fungi, etc.) break down organic molecules (like glucose) to release energy. The general equation for aerobic cellular respiration is:

$$\ce{C_6H_{12}O_6 + 6O_2 ightarrow 6CO_2 + 6H_2O + Energy (ATP)}$$

During this process, the carbon that was previously fixed in organic compounds (from photosynthesis) is converted back into carbon dioxide and released into the atmosphere. This returns carbon to the inorganic pool (atmospheric $\ce{CO_2}$) so that it can be taken up again by plants for photosynthesis, thus completing the carbon cycle.

• Oxygen Cycle: Cellular respiration consumes oxygen from the atmosphere. Aerobic respiration uses oxygen to oxidize glucose and release energy. The oxygen used in respiration is the same oxygen that was produced by photosynthesis. This consumption of oxygen by respiring organisms, along with the production of oxygen by photosynthetic organisms, helps to maintain the balance of oxygen in the atmosphere.

In summary, photosynthesis takes in $\ce{CO_2}$ and releases $\ce{O_2}$, while cellular respiration takes in $\ce{O_2}$ and releases $\ce{CO_2}$, and together they drive the continuous cycling of carbon and oxygen between the atmosphere, living organisms, and other parts of the ecosystem.

Answer:

• Photosynthesis: In the carbon cycle, it fixes atmospheric $\ce{CO_2}$ into organic carbon (e.g., glucose). In the oxygen cycle, it releases $\ce{O_2}$ into the atmosphere.
• Cellular Respiration: In the carbon cycle, it releases $\ce{CO_2}$ (from organic carbon breakdown) back to the atmosphere. In the oxygen cycle, it consumes atmospheric $\ce{O_2}$.

Together, they balance the flow of $\ce{C}$ and $\ce{O}$ between the atmosphere, organisms, and the environment.