Final answer:
Biological molecules serve as energy sources by being involved in chemical reactions that transfer and transform energy within the cell. ATP and NADPH are universal carriers, fundamental for various cellular processes, and ATP is recycled within the cell to continually provide energy. The laws of thermodynamics govern these energy transformations.
Step-by-step explanation:
How Biological Molecules Serve as Energy Sources-
All organisms require energy sources for metabolic activities. To discuss how biological molecules serve as energy sources, we first acknowledge two universal energy-carrying molecules: ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). These molecules are crucial because while ATP is the primary energy currency for cellular activities, NADPH plays a significant role in anabolic reactions, including photosynthesis and lipid synthesis, where reducing power is needed.
Regarding the superiority of one molecule over another, it’s not about one being better than the other, but more about the suitability for specific functions within the cell. For instance, a single cell uses about 10 million ATP molecules per second, which demonstrates the importance of ATP in energy transfer. ATP releases energy when its high-energy phosphate bonds are broken, which is then used for various cellular processes. After releasing energy, ATP converts into ADP (adenosine diphosphate) and is recycled back into ATP through cellular respiration.
Overall, organisms capture energy either through photosynthesis, using energy from the sun, or through consumption of other organisms. They then convert and store this energy in biomolecules like carbohydrates, which are ultimately broken down via cellular respiration to produce ATP, allowing for energy transfer within cells.
The laws of thermodynamics govern the energy transformation and ensure that while energy is exchanged, it is not created or destroyed, only transformed within the biological system.