then it's just bbq chicken from there 🎥 crash course ochem sn1 and sn2 "When considering whether a nucleophilic substitution is likely to occur via an SN1 or SN2 mechanism, we really need to consider three factors: 1) The electrophile: when the leaving group is attached to a methyl group or a primary carbon, an SN2 mechanism is favored (here the electrophile is unhindered by surrounded groups, and any carbocation intermediate would be high-energy and thus unlikely). When the leaving group is attached to a tertiary, allylic, or benzylic carbon, a carbocation intermediate will be relatively stable and thus an SN1 mechanism is favored. These patterns of reactivity of summarized below. 2) The nucleophile: powerful nucleophiles, especially those with negative charges, favor the SN2 mechanism. Weaker nucleophiles such as water or alcohols favor the SN1 mechanism. 3) The solvent: Polar aprotic solvents favor the SN2 mechanism by enhancing the reactivity of the nucleophile. Polar protic solvents favor the SN1 mechanism by stabilizing the transition state and carbocation intermediate. SN1 reactions are called solvolysis reactions when the solvent is the nucleophile." #ochem #organicchem #chemistry #chemistrymajor #biologymajor

and probably has a reaction lined up after evolution at their common ancestor's firm 🎥 crash course biology cellular respiration "Pyruvate dehydrogenase (PDH) is one of the two component enzymes of a huge pyruvate dehydrogenase complex, which is located in mitochondria to catalyze conversion of pyruvate to acetyl-CoA, the entry substrate for the TCA cycle [102]. PDH performs a decarboxylation of pyruvate and a reductive acetylation of lipoate, which is covalently bound to the second enzyme component. PDH is regulated by pyruvate dehydrogenase kinase (PDK), which phosphorylates PDH, and phosphorylated PDH is not active. Because the activity of PDH is critical for the oxidative phosphorylation of glucose, it has been a general assumption that PDH activity is compromised, but PDK is active, in cancer cells in which the majority of pyruvate has to be converted to lactate. This notion creates a paradoxical situation in which PDH inhibition is a valid strategy for cancer therapy." #biochem #biology #cellbiology #metabolism

other halides got patched 🎥 crash course ochem alkenes and electrophilic addition "One of the most important reactions for alkenes is called electrophilic addition. In this chapter several variations of the electrophilic addition reaction will be discussed. Each case will have aspects common among all electrophilic addition. In this section, the electrophilic addition reaction will be discussed in general to provide a better understanding of subsequent alkene reactions. As discussed in Section 6-5, the double bond in alkenes is electron rich due to the prescience of 4 electrons instead of the two in a single bond. Also, the pi electrons are positioned above and below the double bond making them more accessibly for reactions. Overall, double bonds can easily donate lone pair electrons to act like a nucleophile (nucleus-loving, electron rich, a Lewis acid). During an electrophilic addition reactions, double bonds donate lone pair electrons to an electrophile (Electron-loving, electron poor, a Lewis base). There are many types of electrophilic addition, but this section will focus on the addition of hydrogen halides (HX). Many of the basic ideas discussed will aplicable to subsequent electrophilic addition reactions. General Reaction Overall during this reaction the pi bond of the alkene is broken to form two single, sigma bonds. As shown in the reaction mechanism, one of these sigma bonds is connected to the H and the other to the X of the hydrogen halide. This reaction works well with HBr and HCl. HI can also but used but is is usually generated during the reaction by reacting potassium iodidie (KI) with phosphoric acid (H3PO4)." #ochem #organicchemistry #chemistry

are you a monosaccharide? ive never meant anyone as sweet as you😣 footage from hybrid biomedical "Paleoproteomics, the study of ancient proteins, is a rapidly growing field at the intersection of molecular biology, paleontology, archaeology, paleoecology, and history. Paleoproteomics research leverages the longevity and diversity of proteins to explore fundamental questions about the past. While its origins predate the characterization of DNA, it was only with the advent of soft ionization mass spectrometry that the study of ancient proteins became truly feasible. Technological gains have allowed increasing opportunities to better understand preservation, degradation, and recovery of the rich bioarchive of ancient proteins found in the archaeological and paleontological records. Growing from a handful of studies in the 1990s on individual abundant ancient proteins, paleoproteomics today is an expanding field with diverse applications ranging from the taxonomic identification of highly fragmented bones and shells and the phylogenetic resolution of extinct species to the exploration of past cuisines from dental calculus and pottery food crusts and the characterization of past diseases. More broadly, these studies have opened new doors in understanding past human–animal interactions, the reconstruction of past environments and environmental changes, the expansion of the hominin fossil record through large scale screening of nondiagnostic bone fragments, and the phylogenetic resolution of the vertebrate fossil record. Even with these advances, much of the ancient proteomic record still remains unexplored. Here we provide an overview of the history of the field, a summary of the major methods and applications currently in use, and a critical evaluation of current challenges. We conclude by looking to the future, for which innovative solutions and emerging technology will play an important role in enabling us to access the still unexplored “dark” proteome, allowing for a fuller understanding of the role ancient proteins can play in the interpretation of the past. Although proteins decay, nitrogen recycling is not completely efficient, and in protected environments (e.g., bones, teeth, eggshell) proteins can persist for millions of years or more. Protein fragments are recognizable in fossils (e.g., seeds, b0ne), worked biological remains, (e.g., wood, textiles, archaeological and art historical artifacts), as residues on cooking vessels, and also entrapped within soils and sediments. There is more protein nitrogen in this “d34d pool” than there is in all the living cells on earth. Encoded by DNA, proteins pack the same amount of sequence information into approximately one-sixth the number of atoms. For example, a 50 bp fragment of DNA (30.4 kDa) has a larger mass than many intact proteins, including β-lactoglobulin (18.4 kDa), hemoglobin (15.9 kDa), and amelogenin (24.1 kDa). Protein folding and aggregation further protect proteins from chemical attack and facilitate entrapment. With fewer atoms, fewer chemical bonds, and a more compact structure, proteins consequently fall apart more slowly than DNA. However, the greater range of reactive species and our limited ability to recover direct information about their state of decay mean that ancient proteins stretch the limits of our understanding of decay processes and diagenetic modification. Yet the results are hardly esoteric, as modifications associated with ancient proteins have relevance for understanding aging and diseased tissues, and are induced during the production and consumption of protein-containing materials and foods." #biology #guthealth #gutmicrobiome

and then all the ideal gas molecules descended from the skies to carry you away. CW: emotional "Many chemists had dreamed of having an equation that describes relation of a gas molecule to its environment such as pressure or temperature. However, they had encountered many difficulties because of the fact that there always are other affecting factors such as intermolecular forces. Despite this fact, chemists came up with a simple gas equation to study gas behavior while putting a blind eye to minor factors. When dealing with gas, a famous equation was used to relate all of the factors needed in order to solve a gas problem. This equation is known as the Ideal Gas Equation. As we have always known, anything ideal does not exist. In this issue, two well-known assumptions should have been made beforehand: the particles have no forces acting among them, and these particles do not take up any space, meaning their atomic volume is completely ignored. An ideal gas is a hypothetical gas dreamed by chemists and students because it would be much easier if things like intermolecular forces do not exist to complicate the simple Ideal Gas Law. Ideal gases are essentially point masses moving in constant, random, straight-line motion. Its behavior is described by the assumptions listed in the Kinetic-Molecular Theory of Gases. This definition of an ideal gas contrasts with the Non-Ideal Gas definition, because this equation represents how gas actually behaves in reality. For now, let us focus on the Ideal Gas." #genchem #chemistry #chemtok #gaslaw