#biochemical pathways

[apebellica]

It's me. The House is me.

[frank-olivier]

In the Beginning: A Scientific Exploration of Life’s Hypothetical Origins

In the most profound of inquiries, humanity seeks to comprehend the genesis of its own existence, prompting a meticulous examination of the Earth’s primordial landscape. This quest to unravel the mysteries of life’s origins has captivated scientists and scholars for centuries, leading to a nuanced understanding of the intricate interplay between chemical, biological, and environmental factors that potentially gave rise to the first living organisms.

Approximately 4 billion years ago, the Earth’s canvas was vastly different from the one we know today, with minimalistic cells emerging amidst this alien landscape. Characterized by carboxylic acid membranes and RNA-driven heredity, these primitive entities laid the foundational blueprint for the astounding complexity that would eventually follow. The evolution of ribozymes, capable of catalyzing metabolic reactions, was a seminal moment, bridging the gap between a lifeless chemistry and the nascent biochemistry of early organisms. This development not only enhanced cellular capabilities but also underscored the symbiotic relationship between genetic innovation and environmental pressures.

The pursuit of energy, a fundamental drive in the evolution of life, led early organisms to harness the planet’s primordial power sources. Mineral catalysis and reactive phosphorus species might have played crucial roles in the synthesis of ATP, with the Wood-Ljungdahl pathway exemplifying the resourcefulness of these early life forms in exploiting available energy sources.

Our exploration of the Earth’s history leads us to Luca, the Last Universal Common Ancestor, whose characteristics offer a fascinating glimpse into the life of our most ancient shared forebear. The proposed environment of Luca, akin to the chemistry-rich settings of volcanic vents, underscores the profound connection between life’s emergence and the planet’s geochemical landscape. Furthermore, the concept of the Origin of Life Domain (OLD) invites us to contemplate the possibility of alternative life forms, unconnected to Luca’s lineage, and the uncharted scientific territories that await discovery.

From the First Organism to LUCA - The Evolution of Life's Core Processes (Wolfpack Astrobiology, March 2024)

Life Began Much Faster Than We Thought (Sabine Hossenfelder, December 2024)

Saturday, December 7, 2024

[owlscatsandvampirebats-blog]

Told Stories of the RE: Citrullinemia

My friends made this video for a school project. They're Biochemistry majors!

Give 'em a hand. Watch, comment, like, share!

Thanks!!!

[tellurol]

[itsokaytobesmart]

Mapping the Wonder Inside Every Cell

Behold the biochemical pathways of the cell. For decades, these wall charts have adorned the hallways and laboratories wherever biochemists are at work. They are at once both reference and art.

The version pictured above (click here for the holycraphuge version) is state of the art, a subway map of interacting pathways, intersecting reactions, and a road map for the journey to make any building block our cells need. Each node is an enzyme or product, separated by color into metabolic subdomains. You really must head over to KEGG and play with the interactive version, where each dot comes alive, an interactive chemical structure.

I'm also a big fan of Gerard Michal's legendary wall charts of yesteryear. Watching the evolution in design from his 1974 version to a later 1993 map, his layouts are chock full of vintage German aesthetic.

[bi010gic]

The best response we have received to the question, "Does solving the Steiner tree problem shed any light on the biochemical pathway chart?" is below.

Yes. Random approaches to solving interconnectivity problems are useless for all but the most trivial cases. If one doesn't have (n!) time to wait around for a solution, the application of intelligently devised heuristic methods is required. For smallish Steiner Tree problems with fewer nodes, an intelligent agent can trivially generate good solutions by quickly sketching a few lines. For something with the intricate complexity and functionality requirements of a set of biochemical pathways, substantial amounts of careful planning and explicit coordination, not to mention raw and inexplicable artifice, would be required to establish it. I don't think solutions to the Steiner Tree Problem does this justice in the least. It's apparent that nodes in the biochemical pathway are cascade-dependent, with subsequent events (nodes) relying on the successful execution of previous ones. In that way, there are very specific constraints on how nodes must interconnect. Simply finding an efficient method for connecting nodes will just not do. The constraints on the functional interconnectivity of dependent nodes are explicit in the configuration. This problem (evolution of biochemical pathways) is massively more sophisticated than a Steiner Tree or a Traveling Salesman Problem. If solving a simple spanning problem requires intelligent input (in order to avoid waiting until cosmic heat death for a solution) then it stands to reason that a substantially more complex and constrained process would also necessitate a craft, and one of the highest order.

Chance Ratcliff

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