Rachel Green (Johns Hopkins U., HHMI) 1: Protein synthesis: a high fidelity molecular event

www.ibiology.org/biochemistry...
Talk Overview:
In her first talk, Green provides a detailed look at protein synthesis, or translation. Translation is the process by which nucleotides, the “language” of DNA and RNA, are translated into amino acids, the “language” of proteins. Green begins by describing the components needed for translation; mRNA, tRNA, ribosomes, and the initiation, elongation, and termination factors. She then explains the roles of these players in ensuring accuracy during the initiation, elongation, termination and recycling steps of the translation process. By comparing translation in bacteria and eukaryotes, Green explains that it is possible to determine which components and steps are highly conserved and predate the divergence of different kingdoms on the tree of life, and which are more recent adaptations.
Green’s second talk focuses on work from her lab investigating how ribosomes detect defective mRNAs and trigger events leading to the degradation of the bad RNA and the incompletely translated protein product and to the recycling of the ribosome components. Working in yeast and using a number of biochemical and genetic techniques, Green’s lab showed that the protein Dom34 is critical for facilitating ribosome release from the short mRNAs that result from mRNA cleavage. Experiments showed that Dom34-mediated rescue of ribosomes from short mRNAs is an essential process for cell survival in higher eukaryotes.
Speaker Biography:
Rachel Green received her BS in chemistry from the University of Michigan. She then moved to Harvard to pursue her PhD in the lab of Jack Szostak where she worked on designing catalytic RNA molecules and investigating their implications for the evolution of life. As a post-doctoral fellow at the University of California, Santa Cruz, Green began to study how the ribosome translates mRNA to protein with such accuracy.
Currently, Green is a Professor of Molecular Biology and Genetics at the Johns Hopkins School of Medicine and an Investigator of the Howard Hughes Medical Institute. Research in her lab continues to focus on the ribosome and factors involved in the fidelity of eukaryotic and prokaryotic translation.
Green is the recipient of a Johns Hopkins University School of Medicine Graduate Teaching Award as well as the recipient for numerous awards for her research. She was elected to the National Academy of Sciences in 2012.

[@Astoremus]

Thank You! This is the most complete video I've watched on the subject :)

[@rich5034]

Thank you so much. This is above my level at the present time (HS physics teacher, teaching Bio to at risk students), however full comprehension of these concepts and processes is one of the goals for my students for this semester.

[@BulentErdemir]

Very informative. Highly appreciated. Thank you very much..

[@Dumbpuppet101]

this was awesome! so informative and interesting! thank you!!

[@ThePotLabPhD]

Best Molecular Biology professor! Highly recommend! :)

[@AtlasGaming4k]

Not a biologist or student, but love watching iBiology videos and learning!

[@Muuip]

Excellent presentation! Thank you!

[@MarceloRodrigues-ff6vc]

Gosh, what a incredibly didactic explanation! Thx a lot!

[@Bart_Allen_YT]

Nicely summarised video on Protein Synthesis.

[@sambasivaraovejendla5274]

Focussed on the topic throughout without losing time. "Quick and on the target 🎯"

[@stevestandley5571]

Rachel, you did a fantastic job in this video. Very coherent.

[@ambedkarpriyankarthikeyan301]

wonderful presentation!!

[@SrinivashM29]

Thank you. Enjoyed the lecture a lot! Especially termination of translation and the evolution part. Interesting to think about protein synthesis in the cells that were extant before prokaryotes and eukaryotes split. Didn't quite understand the chemistry of how the editing site of aminoacyl tRNA synthase.

[@parakhmody1413]

May I refer you to an equally interesting lecture series for aminoacyl trna synthetase: kzbin.info/www/bejne/emq0e2dqr6qBmLcsi=p9rXeJ8kVgFjiH_S

[@tribikrambarai4988]

Really informative. Thanks ibiology.

[@jimrutin]

Excellent explanation. Thank you.

[@xiomarabianco3147]

q bárbaro lo de rachel green, pasó de moza a diseñadora para ralph lauren y ahora hace buenísimos videos re informativos :)

[@rogerscottcathey]

Keep thinking of chicken/egg paradox. There has to be an RNA creature first it seems. It is so deliciously complex. One sees independent action by parts pinched off of a wandering cell, having no DNA nor RNA content, but doing things. Somewhere in there is a vital clue as to the most primeval unit.

[@rogerscottcathey]

in another video this series I'm still in awe over the transcription error fraction stat. It is stupifyingly rare.

[@westfield90]

I wish this video was around when I was in school. I certainly would have pursued a career in biology

[@nileshgodbole5955]

Awesome information.

[@dcolb121]

1st: It's amazing that cells do this millions of times every second continually throughout the body. 2nd: It's amazing that mankind has figured out how this works up to this point.

[@morisakukatsumon5967]

Gotta respect how she's standing for 43 minutes..some of us are just built different.

[@josephcoon5809]

Transcription begins with Gold Gold: Au is the chemical abbreviation for gold, and G is the first initial. 6:00 Why do you list them in the UCAG order when if you put them in alphabetical order, you’ll have A as the start bit and U as the stop bits?

[@KJKP]

Excellent.

[@rockapedra1130]

Excellent!

[@krishnanviswanath268]

for instance, @6.26 how does ribosome "know" to stop when "it" sees a UAA or UGA or UAG? what is the mechanism by which ribosome stops?

[@KenrickLeiba]

There is a special protein called a release factor that binds to the A site of the ribosome. It’s almost like a dummy tRNA that causes translation to terminate. It’s a little more complicated than that but if you Google release factor you can read more about it.

[@George-pl7dw]

Fascinating

[@Muuip]

Question: What is the connection between Zinc, Zinc-Finger, ribosome hibernation and corona virus?

[@medielijah]

All do not make sense for the average American citizen. You tell me!

[@thinker5280]

What factors might affect errors in protein synthesis?

[@DSAIRAMMSI]

Readthrough errors, Frameshift mutations, Premature Termination/Stalling, Immature subunits,misincorporation of amino acids and tRNA misacylation are some factors that I can think of at the top of my head.

[@IsleofWightBushcraft]

Excellent explanation, thank you. One question. At the outset, You mention that information is read. Where does the information come from.

[@discipleoferis549]

When scientists like chemists or molecular biologists talk about "information", they're basically referring to ordered structure. In this case, the information is the order of nucleotides in a chain. What's particularly interesting is that nucleotides dissolved in water spontaneously form random chains, with most chains being rather short-lived before breaking apart. However, certain chains will be longer-lived than others based on their structure. In this simple example, the "information" would just be the consequent order of relatively stable chains. If you're interested in the study of abiogenesis, this is one proposal for how self-replicating complex chemical structures might have arisen, with some major work being done in this area (called the RNA world hypothesis) in 2009 and 2015.

[@KenJackson_US]

If your explanation were accurate, @@discipleoferis549, one would expect either random noise or repeating patterns like sand dunes. Neither would code for functional proteins and RNA.

[@allensmith342]

@@KenJackson_US Jeffrey demonstrates the difference between those who are biased toward their own atheistic belief system and those who follow the science wherever it may lead.

[@KenJackson_US]

Is there any actual science that _"may lead"_ to a naturalistic origin of life, @@allensmith342? It seems to me that the more science teaches us, the more we realize life was designed.

[@allensmith342]

@@KenJackson_US Perhaps I should've stated that more clearly. I intended to say that actual science (not the biased conclusions of atheistic scientists) leads to the conclusion that, given its complexity, life could not have occurred through purely natural means. Furthermore, the whole concept of abiogenesis violates the 2nd law of thermodynamics which states that in a closed system order moves toward disorder. Disorder cannot move toward order unless acted upon by an extrinsic force. Therefore, the force that brought lifeless, disordered molecules together to form an ordered, living organism would've had to have been God, in my opinion.

[@grantbarnes3678]

Thanks for this. Have you considered uploading at a higher quality? I can’t read the slides on my phone.

[@allensmith342]

Then read them from a computer screen, dumbass.

[@user-ij5sg5yg3e]

Thanks

[@lm1338]

why are they called 5` and 3`, what does the prime mean?

[@briansullivan9110]

Basically the "backbone" of DNA/RNA is made of these sugar molecules that kind of make a circular shape, like a pentagon to be exact. At each point in the pentagon is a Carbon molecule. These Carbons have to be named so we know which Carbon is which. The 5' (five prime) is "above" or "before" the 3' (three prime) in the "backbone." This is the common direction in which things work for DNA/RNA. That's why they say 5' (five prime) to 3' (three prime.) They are talking about the direction in which the Carbon molecules are lined up.

[@giledgar1948]

Hey, Rachel. Speed kills!

[@TaiwanLife2024]

Is it possible to synthesize proteins in lab?

[@discipleoferis549]

Yes. One approach is called in-vitro protein synthesis. Scientists basically take the protein synthesis machinery out of a cell and then introduce their own sequence of DNA along with the required amino acids and other materials. Then that machinery synthesizes their desired protein nonstop, as long as the conditions are maintained (such as the DNA doesn't deteriorate). EDIT: I should note that scientists have been producing proteins in labs outside of cells for 60 years.

[@atti1120]

Solid phase peptide synthesis is a purely chemical method, with no use of biological machinery

[@allensmith342]

@@discipleoferis549 You should also note that it's not true protein synthesis. It's like transplanting a heart from one person to another, then claiming to have created a human.

[@badrakhariunchimeg1031]

Ribosome ?

[@ofmicenglen]

Amazing how complicated a chemical soup hit by lightning turned out.

[@A_S630]

cool

[@KJKP]

Fun fact, Rachel Green likes to hang out at Central Perk with her friends Monica, Phoebe, Ross, Joey, and Chandler. The barrista has a crush on her.

[@BadReligi0nFan69]

thanks for this comment. Just noticed her name lol. Could you BE anymore insightful.

[@yawnandjokeoh]

Wow

[@shericontrary2535]

does this explain how a cow eats grass then we can eat the cow?

[@allensmith342]

No, it explains how a cow ate your brain because it was made from grass.

[@watermelonsavage2914]

Now I understand the Evangelion Central Dogma reference.

[@vargon557]

This discussion is really very informative. With all the complicated steps and processes involved, it is amazing to see how the "major players" work together to make a single protein from a written code. While she seems to understand the process well, she keeps referring to magic! Magic is not a typical scientific explanation. What is magic? "the power of apparently influencing the course of events by using mysterious or supernatural forces." -Oxford dictionary. She does not dare approach the source of the information embedded in the DNA. Whenever there is a difficulty explaining just how the process actually works, she just calls it "magic." While trying to explain life's molecular machinery from a naturalistic viewpoint, she actually joins the other side by calling on magic as a creative force. I don't know about you, but I don't believe in magic.

[@patldennis]

Then you must reject creationism and intelligent design which are the same thing as magic. Listen have you ever heard of a chef working their magic in the kitchen? Or calling a friend over to help with your computer by working their magic? Do you not understand how figures of speech work?

[@muhammadprabaswara2276]

I thought it was rachel green from friends tho. she seems smart as hell rn

[@layzer80]

simple as a flower, and thats a complicated thing.......

[@KenJackson_US]

Fascinating! I understood a large part of it. But it absolutely boggles the mind how anyone who understands how many nucleotides and amino acids make up a ribosome could possibly think it *evolved.* How many mutations would it require to get from the _earlier_ to the _later_ version? (Mutations that changed or add to both RNA and proteins.) Make an estimate. Multiply the required mutations by a large number to account for natural selection throwing most mutations away because they do damage. Now make some estimates of generations per year and generations per relevant mutation and figure out how many years it would optimally take. I think it would take many *trillion years.* But that's not all. Is there even a possible path for evolution? That is, is it possible to start with a bacterial ribosome and modify it one mutation at a time to get to another observed working version even in *unlimited* time? (The organism must live after each mutation.) All this machinery was clearly *designed.* There is no doubt.

[@weeknieunknowing]

Why is there someone like you commenting on literally every video about genetics? What do you hope to gain by doing that? I'm curious

[@reallysearching]

Why don't you speak for all of us then? I'm pretty sure we'd elect you if you gave us the opportunity, so we don't need to hold the election - you just tell us how it all is for all of us.

[@KenJackson_US]

@@weeknieunknowing: _"What do you hope to gain by doing that? I'm curious[.]"_ Sorry, Weeknie, I don't think I got alerted to your response last month. It's just that now that I've learned what molecular biology has revealed, I'm flabbergasted that people still have faith in evolution.

[@KenJackson_US]

I detect sarcasm, @@reallysearching. It's *_so much_* better and more enjoyable to be amazed by the designs of life than to be sarcastic about people who are amazed.

[@dieNatoren]

@@KenJackson_US you obviously don’t understand evolution. Hahaha.😢

[@briancrane7634]

"I will praise You, for I am fearfully and wonderfully made; Marvelous are Your works, And that my soul knows very well." (Psalm 139:14 NKJ)

[@alexanderpadalka5708]

🗽🗽

[@rmr696]

I was an atheist. After that series of movie, I"ve been starting to believe in God.

[@kwgm8578]

Expression of the protein in the thumbnail has been outlawed in Russia, where any display having colors similar to those of the Ukrainian flag will get you 10 years in the gulag.

[@dcolb121]

Yeah? Link?

[@user-jl3lp3kc3z]

thanks from russia

[@rnami9705]

uwu

[@Install312]

Hey Rachel! How bout you make it interesting huh? This KZbin, yeah? This ain't a goddamn classroom.

[@ShannonSmith4u2]

Odd, how someone would even mention that this massively complex machine evolved from Goo. If you looked at a copier machine, which is nowhere near as complicated, could you even begin to believe that it came out of a pile of electronic parts? That beautiful finish, smooth glass, every wire and part soldered perfectly together? If you did, you'd be mentally off. Just like believing this nonsense.

[@carldombrowski8719]

Why bother with a complex machine if you can just make things walk and talk magically? Also, it's obvious that those complex organisms evolved from simpler organisms. Which evolved from even simpler things. Which evolved from chemical reactions which we know existed under primordial conditions which you call goo. On a side note, we get a lot of beautiful shiny and smooth complex things forming naturally: Crystals, rock formations, geysers and many more. Having a crystal from a more flexible material, which allows variations in structure and with that evolution, is not that far off a thought. Unlike a sky daddy who performs magic.

[@discipleoferis549]

Biology tends to create molecular machines that are far and away more needlessly complex than what an intelligent designer would produce. As you learn more about molecular biology it really begins to feel like nature randomly flailing about into a solution. A truly fascinating and complex solution, yes, but often horribly inefficient and wasteful. There's a lot of structural baggage that's just a result of some functional bit randomly finding itself barely applicable to another function and never really ridding itself of all the unnecessary structures from its old purpose as it's adapted to the new purpose.

[@allensmith342]

@@carldombrowski8719 *"Why bother with a complex machine if you can just make things walk and talk magically?"* One of the stupidest, shallowest statements I've ever heard, Mr. Dumbrowski.

[@allensmith342]

@@discipleoferis549 *"Biology tends to create molecular machines that are far and away more needlessly complex than what an intelligent designer would produce."* How do you presume to know what an intelligent designer other than yourself would produce, Jeffrey?

[@carldombrowski8719]

@@allensmith342 The pot calling the shiny kettle black? :)