From Molecules to Life: A Physicist’s Search for Biology’s Secrets | Petra Schwille | TEDxTUM
The speaker argues that understanding life requires studying its molecular self-organization within a transformable shell, moving beyond mere replication to achieve controlled self-division. This concept is supported by their developed system using a membrane and five proteins that exhibit constricting behavior in a controlled, molecular environment. The ultimate goal is to bridge the gap between chemistry and life by demonstrating controlled division. ## Theses & Positions - The definition of life, found in textbooks (metabolism, replication, information), is insufficient because it ignores the continuous, progressing story of life. - The ability of even the smallest organism to learn and solve problems is intrinsic to life, a concept framed by Darwin as Evolution. - Understanding life requires investigating how molecules gain the ability to learn and solve problems from fundamental molecular elements. - Life must be understood by measuring interactions within whole cells, not just in isolated solutions. - To understand a system like life, one must either observe it or build it, following Richard Feynman's principle: *"if I have to what I do not create I do not understand."* - Life must solve problems, the first of which is the ability of constituent molecules to self-organize. - A living system must be compartmentalized by a boundary that can transform while maintaining internal integrity to allow for replication. ## Concepts & Definitions - **Life as a phenomenon:** The continuous, progressing story that even the simplest life forms participate in. - **Self-organize:** The ability of molecules to arrange themselves into structures and patterns without external direction. - **Entropy:** The tendency of everything to move towards disorder (the speaker notes life's function is to *beat* entropy). - **Compartmentalization:** The requirement for a living system to be enclosed by a boundary that controls what is kept in and what is kept out. - **Phospholipid membranes:** The natural solution for compartmentalization; thin layers with a water-loving head group and oily tails, forming double layers. - **Self-division:** The necessary function for replication, requiring the system's shell to divide. ## Mechanisms & Processes - **Studying Molecular Dynamics:** Developing a technique using a fluorescent label to quantitatively analyze how molecules interact with each other (e.g., proteins with proteins or DNA). - **Systemic Complexity:** The challenge of studying life requires studying an "incredible number of different molecules and an incredible number of interactions" within a cell. - **Artificial System Construction:** The proposed path to understanding is to build a system from scratch, combining self-organization with a transformable shell. - **Oscillation Reaction:** The mechanism observed in the lab that makes the proteins drive the forming filaments towards the center of the compartment. - **Constricting Volume:** The physical action observed where the protein filaments cause the confined volume to constrict, a necessary precursor to division. ## Timeline & Sequence - **Historical curiosity:** The speaker's initial fascination progressed from fuzzy animals to germs/parasites, and finally to the human brain's capacity for thought. - **Scientific progression:** Initial molecular study in aqueous solution $\rightarrow$ Limitation: insufficient for life $\rightarrow$ Progressed to studying cells $\rightarrow$ Limitation: background noise $\rightarrow$ Focused on a specific cellular system (sea fish) $\rightarrow$ Goal: finding a simple, controllable, yet alive system $\rightarrow$ Current: building an artificial molecular system exhibiting self-organization and controlled constriction. ## Named Entities - **Richard Feynman:** Physicist whose quote is cited to support the idea that understanding requires creation: *"if I have to what I do not create I do not understand."* - **Shinger:** Physicist who lectured on the nature of life while in exile in Ireland during WWII, discussing the concept of life creating order from disorder. ## Numbers & Data - **Five proteins:** The artificial system currently analyzed consists of a membrane and five proteins. - **Five hundred years:** Time elapsed since the invention of the first microscope, which studied biological specimens. - **Eighteen months:** Duration the speaker spent studying the sea fish cellular system. - **Four years:** Time taken to prepare a specific cellular system in a sea fish organism for study. ## Examples & Cases - **Biological observation:** Studying the interaction of proteins with proteins or DNA within a relatively controlled system. - **Limitation example:** The complexity of a real cell, compared to the internet's complexity. - **Experimental observation:** The fluorescently labeled filaments of protein molecules forming and constricting the volume within a compartment. - **Inspiration source:** The process of life "beating entropy" by creating highly controlled structures and patterns. ## Tools, Tech & Products - **Fluorescent label:** Tool used in the PhD research to make molecules visible and measurable. - **Optical table:** Equipment used in physics education for building optical systems. - **Lasers, lenses, and mirrors:** Components used in optics research. - **Artificial protein system:** The current experimental model used to demonstrate self-organization and constriction. ## References Cited - **Darwin:** Person who framed the expression for Evolution almost 200 years ago. - **Shinger:** Physicist whose lectures on life creating order from disorder were cited. - **Richard Feynman:** Physicist whose quote advocates for understanding through creation. ## Counterarguments & Caveats - **Current limitations:** The artificial system is *not yet* at the stage of full replication/division. - **Overconfidence warning:** The speaker cautions that the physical force required for constriction is not yet strong enough. - **The gap:** The constructed system is "very far away from anything that lives." ## Conclusions & Recommendations - The next step after demonstrating controlled division is to determine what the subsequent essential requirement for a truly living system would be. - The speaker proposes the molecular system could continue toward functional self-division. ## Implications & Consequences - **Understanding Life:** Achieving self-organization and controlled division in a synthetic system represents a major conceptual step toward understanding life's essence. - **Energy Input:** Life's perpetual existence necessitates a continuous input of energy to maintain order against entropy. ## Verbatim Moments - *"What is the definition of life?"* - *"the whole thing seems to be a NeverEnding and ever progressing story"* - *"the ability to create Symphonies and Rockets"* - *"if you look closely every even the smallest organism has this ability"* - *"if you want to understand anything from scratch you have to start doing the math"* - *"we can basically build Optical systems all by yourself"* - *"the basics of all life the interaction of molecules"* - *"a cell is not just two molecules it's not 10 molecules it's not thousand molecules it's an incredible number of different molecules and an incredible number of interactions"* - *"if you really want to understand a system such as life you have to create it"* - *"life is able to create order out of disorder"* - *"what you can see over time is that structures are forming these are filaments made out of protein molecules"* - *"we are very optimistic that we have the next factor in our hand to make that possible"* - *"maybe you can see it twice"*