フォノンが,尿酸-リン酸の短く強い水素結合の振る舞いをどのように支配するか
Fabien Fontaine-Vive1, Mark R Johnson, Gordon J Kearley
1Institut Laue Langevin, BP156, 38042 Grenoble Cedex 9, France.
Journal of the American Chemical Society
|March 2, 2006
まとめ
尿酸-リン酸結合における陽子の移動は,温度が上昇するにつれて中間点に向かって移動する. この現象は,振動共鳴だけでなく,フォノン誘発の構造変化によって引き起こされます.
科学分野:
- 固体化学 固体化学
- マテリアルサイエンス 材料科学
- 計算物理学の物理
背景:
- ニュートロン difraktionは,温度上昇で尿酸-リン酸水素結合における陽子の移動を明らかにします.
- 振動共鳴を含む以前の説明は,計算上のサポートが欠けている.
研究 の 目的:
- 尿酸-リン酸の構造的および振動的性質の温度依存性を調査する.
- 短く強い水素結合による陽子の移動の背後にあるメカニズムを明らかにする.
主な方法:
- 固体状態のアビニチオ計算
- 弾力のない中性子散布.
- Ab initio 分子ダイナミクスシミュレーション
主要な成果:
- 観測された陽子移動は,潜在エネルギー表面または熱集団だけでは説明できない.
- Ab initio分子動力学シミュレーションでは,陽子の移動が確認されています.
- フォノンによって引き起こされる構造的変動が,主要なメカニズムとして特定されています.
結論:
- 尿酸・リン酸における陽子の移動は,フォノン駆動プロセスである.
- 温度に依存する構造的変動により,水素結合の潜在エネルギー表面が変化し,陽子の動きが容易になる.
関連する概念動画
Acids, Bases and Neutralization Reactions
An acid-base reaction is one in which a hydrogen ion, H+, is transferred from one chemical species to another. Such reactions are of central importance to numerous natural and technological processes, ranging from the chemical transformations within cells or lakes and oceans to the industrial-scale production of fertilizers, pharmaceuticals, and other substances essential to the society.
Weak Acid Solutions
Few compounds act as strong acids. A far greater number of compounds behave as weak acids and only partially react with water, leaving a large majority of dissolved molecules in their original form and generating a relatively small amount of hydronium ions. Weak acids are commonly encountered in nature, being the substances partly responsible for the tangy taste of citrus fruits, the stinging sensation of insect bites, and the unpleasant smells associated with body odor. A familiar example of a...
Stomach pH Regulation
The human body carefully regulates the internal pH of different organs to maintain homeostasis. For example, while the blood plasma maintains a neutral pH of 7, the stomach lumen has an acidic pH of 1.5 - 3.5. The low pH of stomach lumen helps kill pathogens in the food and break down complex food molecules.
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...
Acids, Bases and Neutralization Reactions
Acids and bases play several important roles in biology. The pH of a biological system can significantly impact the function of biological molecules, including enzymes, proteins, and nucleic acids. For example, enzymes have optimal pH ranges for their activity, and changes in pH can denature or alter their structure, affecting their function. Acids and bases also play a crucial role in cellular signaling and communication. The pH of the extracellular fluid around cells can influence the...
Conductometric Titrations: Strong Acid-Weak Base and Weak Acid-Strong Base Titrations
When a weak acid such as acetic acid is titrated against a strong base like sodium hydroxide, the initial conductance is relatively low due to the weak dissociation of acetic acid. However, as sodium hydroxide is added to the solution, it reacts with the acetic acid to produce highly ionized sodium acetate, which causes an increase in conductance. Once all the acetic acid has been neutralized, any additional sodium hydroxide introduces fast-moving hydroxyl ions, leading to a sharper increase in...
Renal Regulation of Acid-Base Balance
Metabolic reactions in the body produce nonvolatile acids, such as sulfuric acid, which generate an acid load of approximately 1 mEq of H+ per kilogram of body weight daily. Excreting H+ in the urine is essential to balance this acid load.
In the kidneys, cells within the proximal convoluted tubules (PCT) and the collecting ducts secrete hydrogen ions (H+) into the tubular fluid. Specifically, in the PCT, Na+/H+ antiporters secrete H+ while reabsorbing Na+.
However, the intercalated cells in...
In the kidneys, cells within the proximal convoluted tubules (PCT) and the collecting ducts secrete hydrogen ions (H+) into the tubular fluid. Specifically, in the PCT, Na+/H+ antiporters secrete H+ while reabsorbing Na+.
However, the intercalated cells in...


