I will give it a try! I might have just enough pieces to build a small portion of a DNA molecule. Thanks for the great suggestion! 🧬

Great Question! Nitrogen typically forms three covalent bonds because it has three unpaired electrons in its valence shell. However, when nitrogen has a positive charge (one less electron), it can form four covalent bonds, as seen here.

@@LetsGoBio million of thanks

Thank you for your comment 😊 Best of luck!!

Thank you! The grey/white are hydrogens and red are oxygens. (Black are carbon, yellow is phosphorus).

Thank you for your support 🙏🏻 🤓

Hello! 😊 yes, mutations are interesting. A point mutation like the one in the example wouldn’t change the amount of anything - the cell will still read the DNA, create the mRNA transcript and express the protein as usual (the mRNA just now has a different codon in one spot, but that codon codes for the correct amino acid in the protein). There indeed was an effect on the DNA, it was the point mutation which resulted in the changed codon :) A missense or nonsense mutation will likely decrease or halt the amount of (viable) protein produced, depending on where in the gene that mutation occurred.

@@LetsGoBio if silent mutations keep changing away from the original condon set do you not think it will result in a snowball effect of mutational run away until No 'viable' protein is produced , aka mutational extinction from: ccc to :ccg then :gcg the amount of errors increasing the amount of errors

@@bubblegumgun3292 That’s a great question. I don’t know of any reason (or mechanism) where an altered DNA nucleotide sequence (a SNP) would cause more mutations in the DNA sequence. (In other words, I don’t think one silent mutation would cause a second mutation). In fact, every time the human genome replicates itself there are roughly 100 new mutations. The DNA is constantly under threat of mutation, it would be detrimental if one change resulted in a snowball effect. The genetic code also has a genius design to protect us - the third nucleotide position is called the “wobble” position bc of how well it can usually handle mutations without harm to the organism. This is often where silent mutations occur. Silent mutations are common and are a way of tracing related organisms bc they can be maintained through generations at no harm to those organisms. Although I shouldn’t say they are completely harmless. They used to be thought of as such, but I see new research shows they can have negative effects. They can cause an issue if the altered mRNA transcript is supposed to be spliced, and the different codon could affect protein folding rhythm, thereby altering conformation and function. I appreciate your thoughtful and thought-provoking comments! Science is always evolving and it’s always good to revisit these concepts and think about them beyond what is taught in textbooks 📚.

This is a snippet, the full image (with all orbitals) can be fully seen in the full lecture it is from :)

😎 thanks

Thank you so much! 😊 Right now I do only biology fundamentals.

Aw, thanks ☺️

Hi! I’m not familiar with Biology 1201 curriculum to confirm if it’s the same. However, I use multiple textbooks and sources to make sure each lecture is complete and not missing any key topics.

Thank you so much for your lovely comment 🙏🏻✨ so glad it helped!

Of course! What’s the timestamp for when the identification questions are? 🧐

@@LetsGoBio41:50!!! Thank YOUU

Well, I should have numbered these for easier reference 😅. The cells are actually in phase order, starting with the single cell at the left/middle of the image. Then they spiral down, to the right, then up across the top, and into the very center. 1. Interphase: Starting with the cell at the left/middle. It has fully intact nuclear envelopes and the DNA 🧬 is relaxed and unwound so this cell is in interphase - not undergoing mitosis. This is the stage the cells are in 90% of the time and is the “daily living” phase. 2. Prophase: A little below that interphase cell to the right we see a cell with “X” shaped chromosomes. You’d be able to see those under a microscope because they have been wound up and condensed. This is the beginning of mitosis - prophase. You can also see the centrioles (blue) have formed and made their way to the poles to begin forming the mitotic spindle. 3. Prometaphase: Below that to the right at the bottom of the image, you can see the X’s have the blue mitotic spindle attached and are making their way to the middle of the cell for metaphase. Because this is a mix of prophase (condensed chromosomes, breaking down the nuclear envelope) and metaphase (lining up at the center), it’s called prometaphase. (Some text books don’t distinguish between prophase and prometaphase.) 4. Metaphase: Up to the right a little bit you can see the X’s lined up at the center - this is metaphase and probably the easiest to identify. Think meta - middle. 5. Anaphase: Up and to the right of that cell is the next step - anaphase. The X’s are being “pulled apart” by the mitotic spindle, pulled toward the two opposite poles. (The movement is actually caused by the kinetochores moving along the spindle). You can tell it’s just after metaphase because the sister chromatids are still near the center but moving away to the poles. 6. Anaphase: Just above that cell to the left, is still anaphase but its father along. The sister chromatids are moving toward the poles. You can see the beginning of the “pinching” between the two cells. That pinching is the separation of cytoplasm call cytokinesis. * Cytokinesis is distinct from mitosis although they occur simultaneously. Mitosis is specifically about the DNA separation (and the components and events involved), while cytokinesis is about the cytoplasm separating- the pinching and creating of the two cells. Cytokinesis usually is said to happen at the end of anaphase and during telophase. 7. Telophase: To the left of this at the top, the double cell is toward the end of mitosis so it’s experiencing both telophase and cytokinesis (you can see the pinching of the cells and the cleavage furrow.) the nuclear envelopes should begin to reform here and the DNA will begin to loosen. 8. Daughter cells: The end product would be two completely identical daughter cells, which you see overlapping in the very center of the image. They are completely identical to the cell we began with on the left. These cells are again in interphase in “daily living” phase completing the cells normal cellular duties. That was long-winded but hope that helped!

This is from Campbells Biology. You can find the full lecture on my channel - Chapter 17 ✏️