Question

Life Processes Compare the net reactions for photosynthesis and cellular respiration with respect to reactants, products, and energy

Short answer

In summary, photosynthesis and cellular respiration are opposite processes in terms of reactants, products, and energy flow. The net reaction for photosynthesis is \(6CO_2 + 12H_2O + light \to C_6H_{12}O_6 + 6O_2 + 6H_2O\), and the reactants are carbon dioxide, water, and light, while the products are glucose and oxygen. The net reaction for cellular respiration is \(C_6H_{12}O_6 + 6O_2 \to 6CO_2 + 6H_2O + energy\), and the reactants are glucose and oxygen, while the products are carbon dioxide, water, and energy. Photosynthesis is an energy-storing process that uses light energy to create glucose, while cellular respiration is an energy-releasing process that breaks down glucose to generate ATP.

Step-by-step solution

Overview of Photosynthesis and Cellular Respiration

Photosynthesis can be summarized as the process that converts light energy into chemical energy in the form of glucose, while cellular respiration breaks down glucose to produce energy as ATP. These processes can be represented in their respective chemical equations.

Photosynthesis Net Reaction

The photosynthesis reaction takes place in plants' chloroplasts, where light energy is converted into chemical energy stored in glucose. The net reaction for photosynthesis can be written as: \[6CO_2 + 12H_2O + light \to C_6H_{12}O_6 + 6O_2 + 6H_2O\] Reactants: Carbon dioxide (CO_2), Water (H_2O), and light Products: Glucose (C_6H_{12}O_6), and Oxygen (O_2) In this reaction, the plant absorbs light energy, which is used to convert six molecules of carbon dioxide and twelve molecules of water into one glucose molecule and six oxygen molecules.

Cellular Respiration Net Reaction

Cellular respiration occurs inside the mitochondria in all living cells, where glucose is broken down, and ATP is produced. The net reaction for cellular respiration can be written as: \[C_6H_{12}O_6 + 6O_2 \to 6CO_2 + 6H_2O + energy\] Reactants: Glucose (C_6H_{12}O_6) and Oxygen (O_2) Products: Carbon dioxide (CO_2), Water (H_2O), and energy In this reaction, one glucose molecule and six oxygen molecules are converted into six carbon dioxide molecules, six water molecules, and energy in the form of ATP.

Comparing Reactants, Products, and Energy

Upon comparing both reactions, we can observe the following relationships: 1. The reactants of photosynthesis - carbon dioxide and water, along with energy from sunlight, are the products of cellular respiration. 2. The products of photosynthesis - glucose and oxygen, are the reactants of cellular respiration. 3. Photosynthesis uses light energy to convert carbon dioxide and water into glucose and oxygen, while cellular respiration releases energy stored in glucose in the form of ATP. 4. Photosynthesis is an energy-storing (endergonic) process, and cellular respiration is an energy-releasing (exergonic) process. In summary, photosynthesis and cellular respiration are opposite processes in terms of reactants, products, and energy flow. Photosynthesis stores energy from sunlight in glucose molecules, while cellular respiration releases that stored energy and makes it available to cells in the form of ATP.

Key concepts

Reactants and Products of Photosynthesis

Photosynthesis is the biological process by which plants, algae, and some bacteria convert light energy into chemical energy. In simple terms, they use sunlight to turn water and carbon dioxide into glucose, a sugar that serves as a crucial energy source, and oxygen.

The chemical equation for photosynthesis is:
\[6CO_2 + 12H_2O + light \to C_6H_{12}O_6 + 6O_2 + 6H_2O\]
This process takes place in the chloroplasts, using chlorophyll to capture sunlight. The reactants are carbon dioxide (\(CO_2\)) and water (\(H_2O\)), and, importantly, light is also required. The products are glucose (\(C_6H_{12}O_6\)) and oxygen (\(O_2\)). Understanding these inputs and outputs is crucial both for biology students and for appreciating the fundamental biological processes that sustain life on Earth.

Reactants and Products of Cellular Respiration

Cellular respiration is a set of metabolic reactions in cells to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products.

The equation for cellular respiration is:
\[C_6H_{12}O_6 + 6O_2 \to 6CO_2 + 6H_2O + energy\]
This vital process happens in the mitochondria of cells. The reactants are glucose (\(C_6H_{12}O_6\)) and oxygen (\(O_2\)), and the products are carbon dioxide (\(CO_2\)), water (\(H_2O\)), and energy in the form of ATP. Cellular respiration allows organisms to use the energy stored in glucose to power necessary life functions—a testament to the intricacy and efficiency of biological systems.

Energy Conversion in Biological Processes

In both photosynthesis and cellular respiration, energy conversion is a key component. Photosynthesis captures energy from sunlight and stores it chemically in glucose molecules.

Later, cellular respiration converts this chemical energy into a form that cells can use for work, mainly ATP. This beautifully orchestrated energy flow is central to life on Earth, providing a continuous energy source for all living organisms. The conversion of energy forms follows the laws of thermodynamics and highlights the efficiency of biological systems in harnessing and utilizing energy.

Comparing Photosynthesis and Cellular Respiration

Though they are different processes, photosynthesis and cellular respiration are inextricably linked. The outputs of one are the inputs of the other; they form a biological loop that recycles matter and energy.

Photosynthesis vs. Cellular Respiration

• Photosynthesis occurs in the chloroplasts, cellular respiration in the mitochondria.
• The former is considered anabolic (building up), while the latter is catabolic (breaking down).
• Photosynthesis requires energy to convert CO2 and H2O into glucose and O2; cellular respiration releases energy by converting glucose and O2 into CO2 and H2O.
• The flow of energy in photosynthesis is from the sun to the glucose molecule, while in cellular respiration, it's from the glucose molecule to ATP.

Understanding these similarities and differences is fundamental to comprehending how life works at a cellular level.

Chemical Equations in Biology

Chemical equations in biology represent the stoichiometry of biochemical reactions—such as photosynthesis and cellular respiration—allowing us to visualize the conservation of mass and transformation of energy.

These equations convey critical information about the quantities of reactants and products, alongside the energetics of the reactions. Mastery of interpreting these chemical equations is not only vital for understanding biological processes but also a foundational skill for anyone pursuing a career in the life sciences.