User:8959j/sandbox

From Wikipedia, the free encyclopedia

Week 3 Tasks - Info for 4-Hydroxy-3-methoxy phenylethanol (HVA)[edit]

Properties of 4-Hydroxy-3-methoxy phenylethanol (HVA)[edit]

  • Molecular Formula:
  • Molar Mass:
  • Melting Point:
  • Boiling Point: at 760 mmHg
  • Solubility in Water: N/A


4-Hydroxy-3-methoxy phenylethanol

4-Hydroxy-3-methoxy phenylethanol Hydroxy group Hydroxy group

Hydroxy group

4-Hydroxy-3-methoxy phenylethanol

Protective effect of hydroxytyrosol and its metabolite homovanillic alcohol on H2O2 induced lipid peroxidation in renal tubular epithelial cells[1]

Radical-scavenging Activity and Antioxidative Effects of Olive Leaf Components Oleuropein and Hydroxytyrosol in Comparison with Homovanillic Alcohol[2]

Biocatalyzed Synthesis and Structural Characterization of Monoglucuronides of Hydroxytyrosol, Tyrosol, Homovanillic Alcohol, and 3-(4′-Hydroxyphenyl)propanol[3]

Practice Uploading a PDB Structure Image[edit]

OxyHemoglobin active ste structure






Critique of Carbonic Anhydrase Mechanism Figure[edit]

  • Arrows in figure are larger than compounds
  • Compounds can be larger
Chemical Properties for 4-Hydroxy-3-methoxy phenylethanol
form 0
Isotope Atom Count 0
Formal Charge 0

Equation of Motion[edit]

Homovanillyl Alcohol
Names
IUPAC name
4-hydroxy-3-methoxy phenylethanol
Properties
C9H12O3
Molar mass 168.19 g/mol
Melting point 41 °C (106 °F; 314 K)
Boiling point 316–317 °C (601–603 °F; 589–590 K)
N/A
log P 0.47
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).







Practice Using History Pages, Talk pages, Article ratings and Watchlists[edit]

Iron-sulfur cluster article[edit]

Smokefoot edited this article by deleting the paragraphs that Ninja Recs included because of the way they contribute to the structure of the article. This paragraph included opening remarks introducing the article and stating what topics would be discussed. The main purpose of Smokefoot editing these paragraphs out can be deduced in Smokefoot's comments, "Wikipedia is not a school essay. It is a compilation of facts." Smokefoot believes the paragraphs Ninja Recs added is unnecessary for a Wikipedia article, and that all that should be included are facts.

Smokefoot also commented, "Rem essay beginning with "taking a look at [4Fe-4S] cluster..." including this student critique of biochemical machinery "Despite the [4Fe-4S] clusters having its benefits and flaws...")

The statistics for these edits are negative numbers because these edits are removing bytes (data) from the article.

In my opinion, these edits were necessary because it makes the information presented in the article more appropriate for what a Wikipedia page should be, a statement of facts.

Wikipedia "Iron-sulfur cluster" article: Talk page discussion of Dec 4th / 5th 2018 edits"[edit]

Hello, I hoping to contribute, my knowledge to this article by discussing the strength, covalency and electron transfer effects. Ninja Recs (talk) 01:00, 12 October 2018 (UTC)[reply]

You are writing at a level that indicates that your teacher is needed. Please ask your teacher to read some Wikipedia articles first. --Smokefoot (talk) 01:20, 5 December 2018 (UTC)

Carbonic anhydrase[edit]

The main purpose of these edits made by Smokefoot were to avoid redundancy. Smokefoot removed what they believed to be any unnecessary information regarding Carbonic anhydrase. Smokefoot did this by shortening what Bilal.bhatti96 entered to avoid redundancy. Another purpose of Smokefoots edits was to add information regarding the mechanism involved in this article. Smokefoot's last edit was made to remove a reference that was repeated.

The statistics for these edits are negative numbers because these edits are removing bytes (data) from the article.

In my opinion Smokefoot's edit to the introduction makes a good improvement to the introduction compared to the previous version that Bilal.bhatti96 had. This edit makes a good improvement to the introduction because Bilal.bhatti96's version seemed redundant. What I thought Smokefoot's edit did well was condense the introduction and remove unnecessary sentences.

In my opinion the new paragraph in Bilal.bhatti96's version makes a good improvement to the introduction because it discusses material relevant to Carbonic anhydrase. For example, the Bohr effect, which involves hemoglobin's oxygen binding affinity. This is relevant to the Carbonic anhydrase as noted in the edit, "carbonic anhydrase speeds up the reaction of carbon dioxide reacting with water to produce hydrogen ions (protons) and bicarbonate ions."

The current version of the carbonic anhydrase article does contain the paragraph added by Bilal.bhatti96.

In my opinion there has not been enough useful discussion about what needs to be done to improve the carbonic anhydrase article. Outside of the conversation regarding the spontaneous conversion of CO2<->HCO3, there has been barely any conversation done to improve the article.

Article Ratings:[edit]

This article has been rated as C-Class on the quality scale

This article has not yet received a rating on the importance scale

First 250 Word Contribution (Unrevised)[edit]

Subtopics:

  • High Covalency
  • Comparison of "ordinary" to TdFe(RS)4 complexes

Types of Contributions:

  • Adding new content: adding a whole new subtopic - High Covalency - and adding new content to Comparison of "ordinary" to TdFe(RS)4 complexes

Article: Iron-Sulphur Proteins[edit]

Subtopic: Structure-Function Principles

Iron-Sulphur proteins affect rapid electron transfers to serve their biological roles.

Iron-Sulphur proteins span the whole range of redox potentials within aqueous solutions from -600 mV to +460 mV. The window of opportunity of redox for the Iron-Sulphur proteins lies within -1 to +1.

For a metalloprotein like Rubredoxin (which is also a small protein), there must be rapid electron transfer (on the millisecond time scale) to keep up with the electron transport process.

Fe3+-SR bonds have unusually high covalency which is unexpected. When comparing the covalency of Fe3+ with the covalency of Fe2+, Fe3+ has almost double the covalency of Fe2+ (20% to 38.4%). Fe3+ is also much more stabilized than Fe2+. Hard ions like Fe3+ normally have low covalency because of the energy mismatch of the metal Lowest Unoccupied Molecular Orbital with the ligand Highest Occupied Molecular Orbital.

Iron-Sulphur clusters and complexes are the most rapid electron transfers of the metalloproteins.

When examining Iron-Sulphur proteins, as the bond length decreases, the wavelength decreases.

The covalency of Iron-Sulphur proteins increasing, means that the H2O’s are decreasing the covalency because HOH-S Hydrogen-bonding pulls the Sulphur electrons therefore less able to donate Sulphur lone pair to Fe3+/2+ since covalency stabilizes Fe3+ more than Fe2+, Fe3+ is more destabilized by the HOH-S Hydrogen-bonding.

The high covalency between Iron and Sulphur is caused by the ferric ion electron exchange and splitting of the spin-up vs. spin-down orbitals. This high covalency lowers the inner sphere reorganization energy and ultimately contributes to a rapid electron transfer.

Revised 250 Word Contribution[edit]

Article: Iron-Sulfur Proteins[edit]

Subtopic: Structure-Function Principles

To serve their various biological roles, iron-sulfur proteins effect rapid electron transfers and span the whole range of physiological redox potentials from -600 mV to +460 mV.

Iron-sulfur proteins are involved in various biological electron transport processes, such as photosynthesis and cellular respiration, which require rapid electron transfer to sustain the energy or biochemical needs of the organism.

Subtopic: High Covalency

Fe3+-SR bonds have unusually high covalency which is expected. When comparing the covalency of Fe3+ with the covalency of Fe2+, Fe3+ has almost double the covalency of Fe2+ (20% to 38.4%) ([4]). Fe3+ is also much more stabilized than Fe2+. Hard ions like Fe3+ normally have low covalency because of the energy mismatch of the metal Lowest Unoccupied Molecular Orbital with the ligand Highest Occupied Molecular Orbital.

The covalency of iron-sulfur proteins increasing means that the H2O’s are decreasing the covalency because HOH-S Hydrogen-bonding pulls the sulfur electrons. Therefore, lower covalency can donate the sulfur lone pair to Fe3+/2+. Subsequently, covalency stabilizes Fe3+ more than Fe2+, Fe3+ is more destabilized by the HOH-S hydrogen-bonding.

The Fe3+ 3d orbital energies follow the “inverted” bonding scheme which fortuitously has the Fe3+ d-orbitals closely matched in energy with the sulfur 3p orbitals which gives high covalency in the resulting bonding molecular orbital[5]. This high covalency lowers the inner sphere reorganization energy[5] and ultimately contributes to a rapid electron transfer.

250 Word Equivalents[edit]

Article: Iron-Sulfur Proteins[edit]

Sub-content: 4Fe-4S Clusters

4Fe-4S Ferredoxin Oxidation States of Fe3+, Fe2.5+, Fe2+


Fe2.5+ refers to "Mixed Valence pairs" of Fe3+-Fe2+ have a greater stability from covalent communication and strong covalent delocalization of the "extra" electron from the reduced Fe2+ that results in full ferromagnetic coupling.



Sub-content: 2Fe-2S Clusters

Rieske 2Fe-2S Cluster Oxidation States of Fe3+ and Fe2+
Ranges of reduction potentials, Eo (mV), covered by the different classes of iron-sulfur proteins, heme proteins, and copper proteins. (HiPIP = High potential iron-sulfur proteins, Rdx = rubredoxins, Fdx = ferredoxins, Cyt = cytochromes.)

Contribution to Live Article[edit]

Article: Iron-Sulfur Proteins[edit]

Subtopic: Structure-Function Principles

To serve their various biological roles, iron-sulfur proteins effect rapid electron transfers and span the whole range of physiological redox potentials from -600 mV to +460 mV.

Iron-sulfur proteins are involved in various biological electron transport processes, such as photosynthesis and cellular respiration, which require rapid electron transfer to sustain the energy or biochemical needs of the organism.

Fe3+-SR bonds have unusually high covalency which is expected. When comparing the covalency of Fe3+ with the covalency of Fe2+, Fe3+ has almost double the covalency of Fe2+ (20% to 38.4%)[4]. Fe3+ is also much more stabilized than Fe2+. Hard ions like Fe3+ normally have low covalency because of the energy mismatch of the metal Lowest Unoccupied Molecular Orbital with the ligand Highest Occupied Molecular Orbital.

There is HO-H—S-Cys H-bonding from external H2O’s positioned by the protein close to the active site and this H-bonding decreases the lone pair electron donation from the Cys-S donor to the Fe3+/2+. Using lyophilization to remove these external H2O’s results in increased Fe-S covalency, which means that the H2O’s are decreasing the covalency because HOH-S Hydrogen-bonding pulls the sulfur electrons. Since covalency stabilizes Fe3+ more than Fe2+, therefore Fe3+ is more destabilized by the HOH-S hydrogen-bonding.

The Fe3+ 3d orbital energies follow the “inverted” bonding scheme which fortuitously has the Fe3+ d-orbitals closely matched in energy with the sulfur 3p orbitals which gives high covalency in the resulting bonding molecular orbital[5]. This high covalency lowers the inner sphere reorganization energy[5] and ultimately contributes to a rapid electron transfer.


Sub-content: 4Fe-4S Clusters

The second cubane shown here with mixed valence pairs (2 Fe3+ and 2 Fe2+), has a greater stability from covalent communication and strong covalent delocalization of the “extra” electron from the reduced Fe2+ that results in full ferromagnetic coupling.

4Fe-4S Oxidation States of Fe3+, Fe2.5+, and Fe2+.

Sub-content: 2Fe-2S Clusters

Rieske 2Fe-2S Cluster Oxidation States of Fe3+ and Fe2+


Ranges of reduction potentials, Eo (mV), covered by the different classes of iron-sulfur proteins, heme proteins, and copper proteins. (HiPIP = High potential iron-sulfur proteins, Rdx = rubredoxins, Fdx = ferredoxins, Cyt = cytochromes.)


References[edit]

  1. ^ Deiana, Monica; Incani, Alessandra; Rosa, Antonella; Corona, Giulia; Atzeri, Angela; Loru, Debora; Paola Melis, M.; Assunta Dessì, M. (2008-09-01). "Protective effect of hydroxytyrosol and its metabolite homovanillic alcohol on H2O2 induced lipid peroxidation in renal tubular epithelial cells". Food and Chemical Toxicology. 46 (9): 2984–2990. doi:10.1016/j.fct.2008.05.037. ISSN 0278-6915.
  2. ^ Umeno, Aya; Takashima, Mizuki; Murotomi, Kazutoshi; Nakajima, Yoshihiro; Koike, Taisuke; Matsuo, Toshiki; Yoshida, Yasukazu (2015). "Radical-scavenging Activity and Antioxidative Effects of Olive Leaf Components Oleuropein and Hydroxytyrosol in Comparison with Homovanillic Alcohol". Journal of Oleo Science. 64 (7): 793–800. doi:10.5650/jos.ess15042.
  3. ^ Khymenets, Olha; Joglar, Jesús; Clapés, Pere; Parella, Teodor; Covas, María-Isabel; de la Torre, Rafael (2006-10-10). "Biocatalyzed Synthesis and Structural Characterization of Monoglucuronides of Hydroxytyrosol, Tyrosol, Homovanillic Alcohol, and 3-(4′-Hydroxyphenyl)propanol". Advanced Synthesis & Catalysis. 348 (15): 2155–2162. doi:10.1002/adsc.200606221.
  4. ^ a b Sun, Ning; Dey, Abhishek; Xiao, Zhiguang; Wedd, Anthony G.; Hodgson, Keith O.; Hedman, Britt; Solomon, Edward I. (2010-08-20). "Solvation Effects on S K-Edge XAS Spectra of Fe−S Proteins: Normal and Inverse Effects on WT and Mutant Rubredoxin". Journal of the American Chemical Society. 132 (36): 12639–12647. doi:10.1021/ja102807x. ISSN 0002-7863.
  5. ^ a b c d Kennepohl, Pierre; Solomon, Edward I. (2003-01-16). "Electronic Structure Contributions to Electron-Transfer Reactivity in Iron−Sulfur Active Sites:  3. Kinetics of Electron Transfer". Inorganic Chemistry. 42 (3): 696–708. doi:10.1021/ic0203320. ISSN 0020-1669.