Some metabolic activities prepare materials the cell no longer needs (cellular waste) for elimination. On the other hand, some metabolic activities break down compounds like glucose and lipid molecules into smaller molecules to provide energy for the cell’s operations. A significant number of metabolic reactions produce small molecules used by the cell’s machinery as building blocks to assemble proteins, DNA, RNA, and cell membrane bilayers. Metabolism also involves reactions of small molecules within the cell’s interior. Metabolic reactions include the production and breakdown of proteins and RNA molecules, DNA replication, and the assembly of cell membranes and cell walls. These processes allow organisms to grow, reproduce, maintain biological structures, and respond to changes in the environment. Metabolic activity makes it possible for life-forms to extract energy from the environment and construct life’s components.
Metabolism refers to the myriad life-sustaining chemical reactions that occur in the cell (and extracellular space in multicellular organisms) that are necessary to sustain life. (For readers familiar with intermediary metabolism and the Krebs cycle, skip ahead to “ The Krebs Cycle and the Origin of Life.”) 1 But careful consideration of the team’s findings suggests that life’s origin more likely stems from the work of a Creator.īut before we discuss their work and its implications, a bit of background information might be helpful. Collaborators from Furman University and the Scripps Research Institute recently highlighted features of the Krebs cycle that seem to support a chemical evolutionary origin of intermediary metabolism and, hence, the origin of life.
Some life scientists think that understanding the design and origin of the Krebs cycle (one of life’s most important and central metabolic pathways) just might be key to understanding the origin of life. This mastery is essential if biochemistry students hope to understand and navigate some of life’s most important biochemical processes. Yet, becoming conversant with the design of metabolic cycles is well worth the effort. These cycles are complex, to say the least, and can be difficult for first-year biochemistry students to master. The roundabouts of London serve as fitting metaphors for the biochemical cycles that contribute to cellular metabolic pathways. Still, I would be hard-pressed to ever become comfortable enough to try driving into some of London’s busiest and more complex roundabouts. Yet, if I needed to, I think I could manage driving in London ‘s quieter areas with a little bit of practice and a whole lot of concentration. I won’t speak for my wife, but I have always been a bit hesitant about driving on the opposite side of the road. Neither of us ever muster ed up enough courage to hire (rent) a car. While there, we have always relied on the Underground and the city buses for transportation. My wife and I have visited London on several occasions.
0 kommentar(er)
