Now, explore each deeply and focus on the microscopic processes themselves, : phenomenological perspective from the entities involved, being as complete and comprehensive as possible
c)
1. DNA Replication: In the double-helix world of DNA, two strands uncoil and separate, each strand serving as a template for a new partner. Nucleotides pair up with their counterparts, under the watchful eye of DNA polymerase enzymes that ensure accurate pairing and bonding. The result is two identical DNA molecules, each a mirror image of the other.
2. Protein Synthesis: Within the nucleus, DNA unzips its coded sequence which is transcribed into messenger RNA (mRNA). The mRNA embarks on a journey from the nucleus to the ribosome in the cytoplasm. Here, transfer RNA (tRNA) molecules, each carrying a specific amino acid, match their anticodons with mRNA codons in a complex molecular puzzle, leading to the formation of protein chains.
3. Neurotransmission: The journey of an electrical impulse along the neuron culminates at the synaptic cleft. Here, neurotransmitter molecules are released, crossing the cleft, and binding to receptors on the post-synaptic neuron, thus propagating the signal. The used neurotransmitters are then either broken down or reabsorbed for reuse.
4. Mitosis and Meiosis: Mitosis involves a parent cell duplicating its DNA and dividing into two daughter cells, each identical to the parent. In contrast, meiosis involves two rounds of division, creating four genetically unique daughter cells, each with half the DNA of the parent cell. This genetic shuffle is crucial for sexual reproduction and genetic diversity.
5. Enzyme Action: Enzymes are the choreographers of cellular biochemistry. They welcome specific substrate molecules into their active site, a perfect fit. Through a process of lowering activation energy, they catalyze the reaction that transforms the substrate into the product, then release the changed molecule back into the cell, ready for the next substrate.
6. Immune Response: Immune cells patrol the body, looking for foreign invaders. Upon detection, they initiate a coordinated response involving identifying the invader, neutralizing it, and remembering it for future reference. This process involves a complex dance between various immune cells such as macrophages, B-cells, and T-cells.
7. Osmosis and Diffusion: For water molecules in a cell, life is a constant journey from places of high concentration to places of lower concentration, maintaining equilibrium. Similarly, other molecules also spread out through diffusion, each moving in a direction that equalizes concentration across the cell.
8. Fermentation: In the absence of oxygen, yeast cells convert glucose into alcohol and carbon dioxide. This process involves a series of biochemical reactions, each step guided by a specific enzyme, transforming the energy-rich glucose molecule into usable energy for the yeast, while producing byproducts that find use in baking and brewing.
9. Electron Transport Chain: Inside mitochondria, electrons from nutrient molecules pass through a series of proteins. Each electron transfer releases energy, which is used to pump protons across a membrane. This creates a gradient that powers the synthesis of ATP, the cell’s primary energy currency.
10. Bacterial Conjugation: Bacteria can transfer plasmids, small loops of DNA, to each other through a process called conjugation. One bacterium extends a pilus to connect to another bacterium and then passes the plasmid through this bridge, a unique form of horizontal gene transfer that spreads beneficial traits through a bacterial population.
11. Virus Replication: Viruses are masters of cellular hijacking. Upon entering a host cell, they inject their genetic material, which commandeers the host’s replication machinery to produce more viruses. The newly formed viruses then burst out of the host cell, ready to infect more cells.
12. Signal Transduction: Cells receive signals from their environment through receptors on their cell membrane. These signals trigger a cascade of biochemical reactions within the cell, which can lead to a variety of responses such as activating genes, changing the cell’s metabolism, or initiating cell division.
13. Cancer Metastasis: When a cell becomes cancerous, it loses its usual constraints. Some of these rogue cells gain the ability to invade local tissues, enter the bloodstream, and travel to distant sites. Once there, they can establish new tumors, a process known as metastasis. This journey involves a complex interplay of interactions with the surrounding environment and other cells.
14. Endocytosis and Exocytosis: Cells constantly interact with their environment, taking in nutrients and expelling waste. In endocytosis, the cell’s membrane wraps around a substance, forming a vesicle that carries the substance into the cell. Conversely, in exocytosis, waste or secretory products are packaged into vesicles that fuse with the cell membrane, releasing their contents outside the cell.
15. ATP Synthesis: ATP synthesis is the cell’s way of storing energy. In mitochondria, glucose is broken down and its energy used to power the pumping of protons across a membrane. This creates a gradient that drives the synthesis of ATP from ADP and phosphate. The ATP molecules then carry this energy to wherever it’s needed in the cell.
16. Photosystem Activity: In the thylakoid membranes of chloroplasts, sunlight excites electrons in chlorophyll molecules, initiating a flow of electrons through photosystems. This flow powers the production of ATP and NADPH, energy-rich molecules that are used in the Calvin cycle to convert carbon dioxide into glucose.
17. Nitrogen Fixation: Certain bacteria have the ability to convert atmospheric nitrogen into a form that plants can use. These bacteria live in the soil or in symbiotic relationships with plants, converting inert N2 into ammonia through a series of enzymatic reactions. This microscopic process is crucial for the global nitrogen cycle.
18. Polymerization: Individual monomers, like small Lego bricks, connect to form larger structures – polymers. This occurs through a series of reactions where a bond is formed between monomers, often releasing a small molecule like water. This process forms the basis of many biological and synthetic materials, including proteins, plastics, and fibers.
19. Cellular Respiration: Cells extract energy from glucose through a process called cellular respiration, which includes glycolysis, the Krebs cycle, and the electron transport chain. This series of reactions breaks down glucose and combines the resulting hydrogen with oxygen to form water, releasing energy that is stored in ATP molecules.
20. Lipid Bilayer Formation: Lipids spontaneously arrange into a bilayer in an aqueous environment due to the properties of their hydrophilic heads and hydrophobic tails. This self-assembly process results in a stable barrier that forms the basis of cell membranes, separating the internal cellular environment from the outside world.
21. Chromatography: Chromatography separates mixtures based on the different affinities of each component for a mobile phase (a liquid or gas) and a stationary phase (a solid or liquid). Components that interact strongly with the stationary phase move more slowly, separating from components that interact more strongly with the mobile phase. This process enables the purification and analysis of complex mixtures.