6:07
Make Carbon disulfide
Make Carbon disulfide
In this video we make a small amount of Carbon disulfide using a ceramic tube and a very hot torch. This reaction is for educational proposes only!!! Do not attempt to reproduce!! Large amounts of toxic gases can form and all products are very flammable. Carbon disulfide is a colorless volatile liquid with the formula CS2. The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent. This video was sponsored by ChemKitDepot.com please visit their sight for all your home chemistry needs.
0:36
Disulfide Bonds
Disulfide Bonds
Disulfide bonds stabilize the structure of many proteins by forming intramolecular bridges. This video is from: Essential Cell Biology, 3rd Edition Alberts, Bray, Hopkin, Johnson, Lewis, Raff, Roberts, & Walter ISBN: 978-0-8153-4129-1
0:24
Disulfide Bonds
Disulfide Bonds
"Disulfide bonds stabilize the structure of many proteins by forming intramolecular bridges. In this example, five disulfide bonds zip up the center of a protease inhibitor. Most extracellular proteins contain disulfide bonds. Disulfide bonds are formed by oxidation of two cysteine residues. In this reaction, the hydrogen atoms are removed from their sulfur atoms to allow formation of the sulfursulfur bond." Essential Cell Biology, Second Edition by Alberts, Bray, Hopkin, Johnson, Lewis, Raff, Roberts, Walter copyright 2004 by Garland Science Publishing
0:38
Carbon Disulfide + Nitrogen Oxide
Carbon Disulfide + Nitrogen Oxide
Professor Saykally demonstrates the carbon disulfide - nitrogen oxide reaction
0:14
Barking Dog Reaction: Carbon Disulfide Reacts With Nitrogen Oxide
Barking Dog Reaction: Carbon Disulfide Reacts With Nitrogen Oxide
Commonly referred to as the "barking dog reation" due to the howling and pop sound given off by carbon disulfide gas reacting with nitrogen oxide gas.
0:34
A disulfide linked model of the complement protein C8γ complexed with C8α indel peptide
A disulfide linked model of the complement protein C8γ complexed with C8α indel peptide
From the Springer article: A disulfide linked model of the complement protein C8γ complexed with C8α indel peptide www.springerlink.com by: Stavrakoudis, Athanassios; (MPG 8.01 MB) Journal: Journal of Molecular Modeling Vol. 15 Issue 2 DOI: 10.1007/s00894-008-0412-y Published: 2009-01-05
0:37
Nitrogen Monoxide + Carbon Disulfide 'Barking Dog' Reaction
Nitrogen Monoxide + Carbon Disulfide 'Barking Dog' Reaction
Filmed during Future of the Spoken Nerd at the Bloomsbury with Andrea Sella.
0:13
Fancy Chemistry---Burning Phosphorus in Carbon Disulfide
Fancy Chemistry---Burning Phosphorus in Carbon Disulfide
The title said it all. It burned with a terrible smell.
2:59
Chemiluminescence from the Explosive Reaction of Nitrous Oxide and Carbon Disulfide, 2008
Chemiluminescence from the Explosive Reaction of Nitrous Oxide and Carbon Disulfide, 2008
UW-Madison Chemistry Prof. Bassam Z. Shakhashiri does a science demonstraiton during the 39th annual "Once Upon a Christmas Cheery, In the Lab of Shakhashiri" in December of 2008. Bassam ignites a mixture of nitrous oxide gas and carbon disulfide vapor in a demo from his newest book, Chemical Demonstrations: A Handbook for Teachers of Chemistry, Volume 5, available from the University of Wisconsin Press. See www.scifun.org for more information.
51:58
Bite-Sized Biochemistry #6: Protein Structure & Characterization
Bite-Sized Biochemistry #6: Protein Structure & Characterization
Lecture by Kevin Ahern of Oregon State University discussing Protein Structure II in BB 450. This course can be taken for credit (wherever you live) via OSU's ecampus. For details, see ecampus.oregonstate.edu See the full course at oregonstate.edu Download Metabolic Melodies at www.davincipress.com Related courses include BB 350 - oregonstate.edu BB 451 - oregonstate.edu BB 100 - oregonstate.edu Highlights Protein Structure IV 1. Ribonuclease is an enzyme that degrades RNA. It is unsually stable. For example, it can be heated up to break its hydrogen bonds, but when cooled down, the enzyme still is active, meaning it has assumed its original shape. 2. Denaturation is a word that means the tertiary and/or quaternary structure of a protein is disrupted. RNase has disulfide bonds that help it to remain resistant to denaturation. 3. Some chemicals, such as mercaptoethanol, can reduce the disulfides (between cysteine residues) in proteins to sulfhydryls. In the process of transferring electrons to the cysteines, the sulfhydryls of mercaptoethanol become converted to disulfides. Treatment of RNase with mercaptoethanol reduces RNAse's disulfides to sulfhydryls. Subsequent treatment of RNase with urea disrupts hydrogen bonds and allows the protein to be denatured. 4. Interestingly, removal of the mercaptoethanol and urea from the solution allows RNase to refold slightly, and regaining activity. Clearly, the primary sequence of this protein is sufficient for it to be able to <b>...</b>
2:37
Elementary Productions: Gas phase chemiluminescence with P4
Elementary Productions: Gas phase chemiluminescence with P4
A suspension of White Phosphorus and Mineral Oil in Carbon Disulfide is made. Some drops of this suspension is placed on a piece of paper, causing the Carbon Disulfide to evaporate. This exposes the White Phosphorus to atmospheric Oxygen. As the White Phosphorus is covered by a thin layer of Mineral Oil, this modifies its reaction with Oxygen, making chemiluminescence in the gas phase clearly visible.
1:48
protein post translational modification
protein post translational modification
Posttranslational modification (PTM) is the chemical modification of a protein after its translation. It is one of the later steps in protein biosynthesis for many proteins. The bottom of this diagram shows the modification of primary structure of insulin, as described. A protein (also called a polypeptide) is a chain of amino acids. During protein synthesis, 20 different amino acids can be incorporated in proteins. After translation, the posttranslational modification of amino acids extends the range of functions of the protein by attaching to it other biochemical functional groups such as acetate, phosphate, various lipids and carbohydrates, by changing the chemical nature of an amino acid (eg citrullination) or by making structural changes, like the formation of disulfide bridges. Also, enzymes may remove amino acids from the amino end of the protein, or cut the peptide chain in the middle. For instance, the peptide hormone insulin is cut twice after disulfide bonds are formed, and a propeptide is removed from the middle of the chain; the resulting protein consists of two polypeptide chains connected by disulfide bonds. Also, most nascent polypeptides start with the amino acid methionine because the "start" codon on mRNA also codes for this amino acid. This amino acid is usually taken off during post-translational modification. Other modifications, like phosphorylation, are part of common mechanisms for controlling the behavior of a protein, for instance activating or <b>...</b>
0:08
Barking dog: N2O and CS2
Barking dog: N2O and CS2
This is a classical experiment, but also a very spectacular experiment. This is a nice demonstration that there are other gases besides oxygen which support combustion. The most spectacular experiment is the use of a long glass tube, filled with nitrous oxide to which some carbon disulfide is added, and which then is ignited. Filling is demonstrated a video here: www.youtube.com After the burning, the tube is covered by a yellow layer of sulphur. Immediately after burning it is fairly bright/dark yellow, but on cooling down, the layer becomes lighter. Discussion of results Nitrous oxide supports combustion of many organic compounds, and when the gas is pure, then it supports combustion even better than plain air. Carbon disulfide also burns very well in this gas. There is not a single nice clean reaction. Carbon disulfide can burn incompletely in nitrous oxide, resulting in formation of elemental sulphur In case of excess N2O there is complete combustion: CS2 + 6N2O → CO2 + 2SO2 + 6N2 When there is excess CS2: CS2 + (6 - 2n)N2O → CO2 + (2-n)SO2 + nS + (6-2n)N2 The value of n depends on the strength of the excess amount (0 ≤ n ≤ 2). In the experiments, described on this page, there was quite some excess carbon disulfide and hence the formation of a clearly visible layer of sulphur, and also some off-white smoke is produced (not visible in the pictures of videos). No carbon soot is produced. Apparently, in carbon disulfide, the carbon first is converted to carbon <b>...</b>
1:57
Elementary Productions: Small scale Barking Dog reaction
Elementary Productions: Small scale Barking Dog reaction
In this video, the classical "Barking Dog" reaction is demonstrated. In this reaction, a vessel is filled with an oxidising gas and a fuel, in this case Nitrous Oxide and Carbon Disulfide. When ignited, the reactants decompose under strong evolution of heat. This is one of the rare examples of luminescence in the gas phase.
49:34
Protein Structure III
Protein Structure III
This course is part of a series taught by Kevin Ahern at Oregon State University on General Biochemistry. For more information about online courses go to ecampus.oregonstate.edu www.youtube.com 1. Another type of fibrous protein is collagen, the most abundant protein in your body. It contains three intertwined helices comprised of abundant repeating units of glycine, proline, and hydroxylproline 2. Hydroxylation of proline is a post-translational modification (occurs after the protein is made) and the hydroxyls are placed there in a reaction that uses vitamin C. 3. The hydroxyls of hydroxyproline can react with other, forming covalent cross-links that make the collagen fibers more sturdy. 4. Tertiary structure relates to interactions between amino acids in a protein that are not close in primary sequence. These interactions are made possible by folding to the protein chain to bring the distant amino acids closer together. 5. Tertiary structure is stabilized by disulfide bonds, ionic interactions, hydrogen bonds, hydrophilic, and hydrophobic interactions. Disulfide bonds are the strongest forces holding tertiary structure together, as they are covalent bonds. 6. Most proteins that are in cells are globular in nature. 7. Myoglobin is protein that acts as an oxygen 'battery', storing oxygen in muscles for when it is needed. Myoglobin contains a heme group that contains iron. Heme is a 'prosthetic group', which refers to a non-amino acid containing group that binds to a <b>...</b>
1:45
Molybdenum
Molybdenum
Name Origin Greek: molubdos (lead-like). "Molybdenum" in different languages. Sources Found in the minerals molybdenite (MoS2) and wulfenite (MoO4Pb) and as a byproduct of copper mining. Primary producers are the USA, Australia, Italy, Norway and Bolivia. Annual production is around 80 thousand tons. Uses In small quantities, molybdenum is effective at hardening steel. Used in aircraft, missiles, filaments in electric heaters and protective coatings in boiler plates. Molybdenum oranges are pigments ranging from red-yellow to a bright red orange and used in paints, inks, plastics, and rubber compounds. Molybdenum disulfide is a good lubricant, especially at high temperatures. Molybdenum is also used in some electronic applications, as the conductive metal layers in thin-film transistors (TFTs).
1:19
How To Grease Trucks: Truck Maintenance with Magnalube-GX Extreme Pressure Grease (Intro)
How To Grease Trucks: Truck Maintenance with Magnalube-GX Extreme Pressure Grease (Intro)
www.magnalube.com In this video, we demonstrate proper truck maintenance procedures by using Magnalube-GX PTFE grease with molybdenum disulfide (or moly). Magnalube-GX is a lithium grease that performs very well as a grease for trucks because the MOLY-PTFE technology improves the ability to withstand extreme pressure and lower friction. It also has a lithium complex base which is compatible with other greases used to grease trucks. If you use Magnalube-GX grease for your fifth wheel and general truck maintenance, it will extend the life of your truck parts as well as decrease the amount of times that truck maintenance is required. Special thanks to Allstate Moving & Transfer Company of Linden, NJ.
46:27
Allostery and Regulation II
Allostery and Regulation II
This course is part of a series taught by Kevin Ahern at Oregon State University on General Biochemistry. For more information about online courses go to ecampus.oregonstate.edu www.youtube.com 1. Zymogens are enzymes that are synthesized in an inactive form whose activation requires covalent modification, usually proteolytic cleavage. Examples include digestive enzymes, such as trypsin, chymotrypsin, elastase, and carboxypeptidase whose enzymatic activity might be harmful to the tissue where they are being made. 2. Trypsin is the primary activator of an entire class of proteolytic enzymes. Improper activation of trypsin in or close to the pancreas can lead to pancreatitis, which arises when the proteases attack proteins in the pancreas. 3. Activation of chymotrypsinogen to chymotrypsin, for example, requires trypsin. Trypsin makes an initial cleavage beween amino acids 15 and 16. A disulfide bond keeps the two pieces from coming completely apart, however. This creates an intermediately active form of chymotrypsin called pi-chymotrypsin. This form cleaves itself to remove two dipeptides and this results in full chymotrypsin activity. The three polypeptide pieces are held together by disulfide bonds. Note that three very minor changes in the chymotrypsinogen zymogen have converted a completely inactive enzyme to a fully active one. 4. Alpha-one-antitrypsin is an inhibitor of many proteases, including trypsin and elastase. Normally alpha-one-antitrypsin binds to elastase <b>...</b>
10:00
Essential amino acid primary-sec-tertiary STRUCTURE jun2010
Essential amino acid primary-sec-tertiary STRUCTURE jun2010
The teriary structure is where the amino acids need God's touch! The primary structure is just the lining up order. The types of bonds that an AA can do is at the beginning. Secondary structure is either the alpha helix or beta-pleated sheet arrangements as it's strung along....adn the tertiary is the complex FOLDING. When a protein is denatured it's this (and the bonds like the disulfide bonds) that are disrupted and not able to resume the function of the enzyme (so a body temperature above the so called 104 Fareinheit can irreversibly damage the enzyme in the brain (for an adult on average)@ 8:35 is the lsit of ESSENTIAL AA's from the book...AA backbone balloon at the end
5:18
F GLUTATHIONE FYI DR. JIMMY GUTMAN ELUCIDATES GLUTATHIONE.mp4
F GLUTATHIONE FYI DR. JIMMY GUTMAN ELUCIDATES GLUTATHIONE.mp4
F-GLUTATHIONE IS A PRODUCT OF CLINICAL SOLUTIONS WITH REAL ANSWERS IN A VARIETY OF MEDICAL CONDITIONS WITH POSITIVE RESULTS. GLUTATHIONE (GSH) is a tripeptide that contains an unusual peptide linkage between the amine group of CYSTEINE (which is attached by normal peptide linkage to a GLYCINE) and the carboxyl group of the glutamate side-chain. It is an antioxidant, preventing damage to important cellular components caused by reactive oxygen species such as free radicals and peroxides.[2] Thiol groups are reducing agents, existing at a concentration of approximately 5 mM in animal cells. GLUTATHIONE reduces disulfide bonds formed within cytoplasmic proteins to CYSTEINEs by serving as an electron donor. In the process, GLUTATHIONE is converted to its oxidized form GLUTATHIONE disulfide (GSSG), also called L(-)-GLUTATHIONE. Once oxidized, GLUTATHIONE reduced back by GLUTATHIONE reductase, using NADPH as an electron donor. The ratio of reduced GLUTATHIONE to oxidized GLUTATHIONE within CELLS USED AS A MEASURE OF CELLULAR TOXICITY THE CRITICAL COMMENT TO MAKE IS THAT WE INTEGRATE 18 PLANTS TO ACCOMPLISH WHAT PHARMACEUTICAL COMPANIES HAVE BEEN UNABLE TO PRODUCE AN ORAL NUTRITIONAL ADDITIVE IN SEVERAL PRESENTATIONS. GLUTATHIONE (γ-L-glutamyl-L-cysteinyl-GLYCINE) is the most abundant soluble REDOX buffer in the cell. GLUTATHIONE pools help maintain the appropriate REDOX environment in the cell. Oxidative stress can result in the oxidation of reduced GLUTATHIONE (GSH) to <b>...</b>
