Episode 7/13: Peptides // A Course on Abiogenesis by Dr. James Tour

In this episode, Dr. James Tour teaches the 2nd class of compounds needed for life: peptides. He identifies gross speculatory claims by others, referring to published literature that confirms the implausibility of the sudden emergence of peptides from amino acids. Dr. Tour also walks the viewer through synthesis, showing that without careful activation, side chain protection, and water-free conditions, amino acids do not polymerize into peptides. He then dispels the view that human-made synthesizers, which were not present on prebiotic earth, somehow render polypeptide synthesis as trivial, let alone the fact that amino acids themselves have never been prepared in homochiral fashion using a prebiotically relevant route. Finally, with no solution to the amino acid sequence that comprises functional proteins, Dr. Tour then shows how some ignore the sequence specificity question necessary for the informational code, and how this dilemma is being pushed to the extraterrestrial in a plea to the heavens.

Video Index:
00:00 - Introduction
00:47 - Reasons & Intent of this Abiogenesis Series
02:58 - On Speculatory Fallacies
06:26 - Synthetic Chemists: "Inconceivable"
10:36 - Interesting Proposal Still Falls Short
12:45 - Basics: Amino Acids, Peptides, Proteins
16:47 - Separating Amino Acids and Peptides
18:29 - Solid-Phase Peptide Synthesis
22:53 - Peptide Structures Explained
26:03 - Protein Synthesizer Machine Prebiotically Relevant?
30:57 - Peptide Synthesis: Requirements and Efficiency
38:23 - Pushing the Amino Acid Sequence to the Celestial
48:13 - Summary, Equilibrium Memo, and What's Next

Links in this Series | Addressing Abiogenesis & Common Misconceptions
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God bless you.

#Abiogenesis #JamesTour #OriginOfLife

~
WeChat - @drjamestour

[richardbristol]

Utterly fascinating and informative series, Jim. I am not a chemist or even a trained scientist, but I’ve been studying origin of life for a decade now, soaking up everything that I can read. I began this journey as an agnostic, leaning atheist. I now understand how completely untenable and demonstrably absurd that viewpoint was/is. Life occurring out of nothing is laughably impossible and it simply never happened. After all of this, I realize that faith, based on knowledge, is a powerful thing indeed. People like Mr. Tour have led me out of the darkness.

[its]

Years ago I knew a doctoral student in chemistry. Ultimately he chose another field citing the frustrating failure rate of chemical experimentation. If he had only lived in prebiotic earth things could have turned out so different.

[nzadventurefamily]

This series is great! Not only do I get to listen to James, but I get to brush up on my chemistry and molecular biology at the same time!

[neilbreakwell]

This should be compulsory viewing in school biology classes. Thanks so much for your enlightening lectures, Jim.

[mrsmith]

What I like about this, is that it knocks it out of the field the commonly held notion that if by chance you have all the ingredients, they will just fall together! As simple as that. Not a chance (literally). The chemistry does not support that & looks as if it never will.

[immanuel]

31:10: "To form this bond you've got to remove water...but you don't remove water when you are in an OCEAN." HILARIOUS!!! Love you Prof Tour :-)

[jamesbell]

The problem of precision and truthfulness is that falsehoods travels 10 miles before truthfulness even gets out of bed. When Prof Dave says a reaction is trivial, it takes 5 seconds to say it and its easy to understand. On the other hand, when Dr. Tour correctly says the reaction is impossible, he needs an hour to explain why it's impossible and the explanation is difficult to understand.

[robinhard]

This is a fantastic series of lectures, thank you so much; a bracing dose of reality.

[patriciaisaviellalloyd]

Pray for my University programmed children who need to hear Dr. Tour

[KenJackson_US]

I figured out why Professor Dave's "rebuttals" are so popular. He delivers a "smack down" style performance filled with *ad hominem attacks* against Dr.Tour's motives and intelligence, whereas Dr.Tour tries to *actually explain* the material so non-scientists can understand it. The "smack down" attack is popular. People enjoy it much more than they enjoy actually learning.

[RainbowSuzy]

Thank you for making these classes so accessible to the layperson!

[tonyaidinis]

Thank you Dr Tour for putting down all this effort! Can't wait every day for your next video, it's so refreshing these days to listen to something that makes sense!

[arulsammymankondar]

5:56 " Pigs could fly" . I am reminded of a story where a criminal sentenced to death, gets a reprieve from the king on the condition that he makes the king's elephant fly. When questioned about the feasibility of his undertaking, the man answered: " There are three possibilities. The king could die before I complete my undertaking or I may die of old age or who knows even the elephant may fly!" The atheists camp is imbued with such optimism .

[rjonesr]

Dave wants to skip over the millions of reactions needed to make the chemicals that go into the machine and just point to the machine and say see it's simple, while ignoring all the intelligent input or ID that made the machine that also works from intelligent input..

[ericakortse]

My favorite phrase.."But somehow, under a rock it figured it out". hahahaha

[Rholfy]

Thank you very much Dr. Tour.
His arguments since chemical synthesis are very solid. I loved your exhibition. I think everyone who speaks Spanish would be very grateful if their series is subtitled.

[Melkor]

Professor Dave's inaccuracies so far: (The best of...)

1. Use of the word Biochemistry. Whilst biochemists do study OoL and biochemicals did exist before life, there was no biochemistry occuring in prebiotic reactions, just plain dead chemistry. Hence the field - prebiotic chemistry and the meaning of the word abiogenesis (origin without biology/non-biological origin). It's a contradiction of terms. It was strictly chemistry. (Anyone who disagrees with this, show me the biochemistry occuring before life began.)

2. Entropy/Thermodynamics argument is an ignorant fallacy?? - a great decrease in entropy WITH a great increase in energy, needed for life, has never ever been observed in the universe without HELP (Dr Brian Miller PhD - expert in thermodynamics), it is a physical impossibility if unaided. Therefore, the examples of ice and soap, order arising (entropy decreasing) from a decrease in energy (driven by nature's preference for a lower energy equilibrium state) as a rebuttal for the argument based upon the 2nd law of thermodynamics is a straw man, it is missing half of the argument. (Anyone who dismisses Dr Miller because he believes in God, prove he is scientifically wrong...)

3. Hype is from the media, NOT the scientists?? - Completely false, Tour's whole video addresses this. Hype can be from the scientists themselves and in many cases the media do consult with them prior to publishing their work, hence they are culpable in this too. Dave has never published a peer reviewed paper so he would not know the intricate details of how this works. (See episode 3 for references)

4. Dave's homochirality assessment is riddled with errors - Tour analysed he actual paper and the SLIGHT excess of asparagine (said in the video) was actually greater than 99% asparagine, an important detail. The enantiomeric excess wasn't pure, for Phe it had a max of 22% of the remaining 1%, a terrible efficiency. The data for other amino acids reveals a broad spread of ee % for both D and L forms, leading the authors to conclude this is just as likely to produce a racemic aftermath as a result, not a homochiral one (from the conclusion of the actual paper).

5. Carbohydrates - Dave states in his video that polysaccharides are repeating units of the SAME monomer, this is utterly false! Many different monomers can make up polysaccharides. Also, use of the word TRICKY in their synthesis is a gross understatement worth mentioning, which Tour goes on to explain in some detail.

6. Any biomolecule is easy to synthesize?? A grossly ridiculous statement. They are hard to synthesize, especially in homochiral form even using ACTIVATE D building blocks taken from nature, side chain protection and removal.. which is common procedure.

7. Primordial soup belief and Honest Talking points - Dave states "to call [seeing a primordial soup of molecules, some lightening and then all of a sudden a cell is there, then maybe a lizard crawling onto land or something like that] a complete view of abiogenesis and evolution would be absurd, but absolutely no one proposes this." Dave states Tour is making a dishonest talking point here, however, Tour shows a video where Lee Cronin (OoL expert) said that Justin Brierley's GCSE [high school] education on his very thing - i.e. "A few lightening strikes and then 'poof!' a cell forms" - was 'not too bad at all". Dr Tour also showed a survey of 697 people, 80% of whom have college degrees, and of this group, ~73% believed scientists researching OoL have created simple life forms via mixing prebiotic chemicals. Therefore 1) it is indeed an honest talking point and 2) Dave's statement "absolutely no one proposes this" has evidence that highly suggests otherwise. (Thanks Bart)

8. Polymer regeneration fallacy. Dave proposed a constant equilibrium reaction to continuously regenerate proteins and RNA from their respective monomers and their even smaller building blocks to overcome Tour's point of molecular degradation over time. This has many catastrophic problems, here's just 3: 1) The equilibrium value would have to be 1 for the required formation/degredation balance. Most reactions do not work like this, it's a thermodynamic fallacy to presume so. The product with the lower energy state is favoured, tipping it's equilibrium one way or the other, not a nice perpetual regeneration. 2) Even ignoring this, many other reactions will occur, not just the desired polymerization. Without side chain protection, racemic, branched JUNK is inevitable. 3) Even ignoring 1 and 2, The polymer needs to be of meaningful sequence to be useful, otherwise it's JUNK! Regeneration of the SAME meaningful sequence is astronomically low - this is before self-replication, therefore anything of potential use would just degrade, likely never to be reproduced.

9. Proteins (could have, may, perhaps) possibly... formed in the ocean from their amino acid monomers. Condensation reactions are mostly ineffective in water, the equilibrium favours the amino acid starting materials. Proteins can be blocked from forming due to the zwitterionic nature of amino acids. Even with an energy source/catalyst, there is little or no control over correct linkage formation. This begs for rethink and a completely alternate route (see Dr Powner's work). Homochirality is bereft of an explanation in any route.

10. His misleading, illinformed slide showing ribonucleotides polymerizing over hot clay is TORN TO SHREDS by Dr Tour. It all looks so easy according to Dave. However.... 1) No prebiotic route to ribose for the starting materials. 2) The clay and the procedure is a prebiotic joke, neither would occur. (Centrifuge 3500rpm??) 3) HOT clay considering the instability of RNA above minus 80??? 4) Catastrophic polymerization problems - wrong linkages causing termination 5) Getting the thing off the clay is even unprebiotic.

11. Cell membranes (Dave "grabbing things out of the air and proclaiming it from the rooftops") Dave's postulated lipid monolayer for protocells is unfounded and is not demonstrated as viable ANYWHERE in the scientific literature and has never been shown to exist. The postulated lipid bilayers devoid of protein gateways or proton gradients would just act as a TOMB for anything inside that may have miraculously formed. Also, the complex non-symmetric bilayers necessary for life do not form spontaneously.

12. Lipids - The spontaneous origin of fatty acids from hydrothermal vents is highly disputed, more likely deriving from oil products of biological origin. Even if we give you the fatty acids.. Salad dressing won't suffice Dave! Lipids made from simple fatty acids are unable to maintain proton gradients essential for life - phospholipids must've been there from the beginning. See episode 10 for their implausible origin.

13. Homochirality1- Given the terrible ee% excess in Dave's example, to stand any chance of leading to homochirality, it would need an exemplary prebiotically relevant autocatalytic reaction inducing enantiomeric amplification. One has never ever been discovered! The only known reaction to do this is the Soai reaction, however, this is - 1) Prebiotically irrelevant 2) Nowhere near efficient enough 3) Nowhere near persistent enough. (Donna Blackmond)
How did proteins become homochiral when there's no prebiotically relevant route ever shown to make the amino acids in homochiral form, or to separate the enantiomers, or to polymerize them?

14. Homochirality2 - Dave claims homochirality could've arrived after life began... Baseless. Implausible. Unscientific. There is no evidence for claimed racemic mixtures (no homochirality) being usable in cells. They have never been shown to function based on the reaction specificities, yields and heat management that would be needed for cellular systems (see CISS in episode 11). Dave suggested this for lipids but VAST numbers of electron transfers take place in lipid bilayer membranes, so it's baseless to dismiss the need for lipid homochirality (see CISS).

15. Dave gets his abiogenesis information from Wikipedia (at best) but more than likely from the Sunday tabloids or his local gazette. When (if) referencing peer reviewed papers, his source material rarely ventures past the abstract of any given paper. If not study the entire paper, at least read it's conclusions which usually provide a more balanced assessment than the abstract. Come on Dave, do your homework!

Thankyou for your time and honesty Mr Tour )) God Bless

[leighneal]

Have you noticed when you make sensible comments on prof Dave “toytown” video you get aggressive emotional reactions from the materialists.

[Josdamale]

We demand more!

We want a symposium of Tour and his peers dealing with each of these topics, out of which we demand a journal for continued research dedicated to the study of abiogenesis and the building blocks of life.

Our appetites have been whet, but our throats are scorched, and our minds are thirsty for more!