乳酸配方——结构、性质、用途、示例问题
具有化学式C 3 H 6 O 3的有机酸是乳酸，也称为牛奶酸。由于与羟基相邻的羧基的存在，它也恰好是α-羟基酸。
当牛奶糖（乳糖）进行发酵时，得到的产物就是乳酸。乳酸存在于白软干酪、黎巴嫩、酸牛奶、酸奶和 Koumiss 中。乳酸左旋和右旋有两种形式的旋光异构体。 1780年，瑞典化学家卡尔·威廉·舍勒首次从酸奶中分离出乳酸。
Lactic acid is water-soluble and white in its solid state whereas it is colourless in its liquid state. lactic acid soluble salt like calcium lactate can be used as a source of calcium.
L-异构体通常存在于活生物体中。乳酸在各种生化过程中起着重要作用。它也是在剧烈活动期间由肌肉产生的。它是无氧呼吸的化学副产物。它由一些细菌在酸奶中产生，也存在于您的肠道和血液中。
乳酸的性质
乳酸的物理性质
| Chemical Formula of Lactic Acid | C3H6O3 |
| Molar Mass/Molecular Weight | 90.08 g/mol |
| Extended Formula of Lactic Acid | CH3CH(OH)CO2H |
| Boiling Point of Lactic Acid | 122°C |
| Melting Point of Lactic Acid | 16.8°C |
| PH of Lactic Acid | 3.51 |
| Colour of Lactic Acid | White in solid-state. Colourless in the liquid state |
| Solubility of Lactic Acid | Soluble in water |
乳酸的化学性质
- 它恰好是一种弱有机酸。此外，它可以与其他更强的酸反应。
- 乳酸还有一个重要的特性就是双重物理状态。
- 这种双重物理状态包括D，L-乳酸的外消旋混合物的液态和对映体的白色固体粉末状态。
乳酸的结构
化学式C3H6O3的有机酸是乳酸，也称为牛奶酸。由于与羟基相邻的羧基的存在，它也恰好是α-羟基酸。
乳酸的制备
Lactic Acid can be prepared from two strategies:
First the biotechnological method: In this method, the large scale production of this acid takes place by the fermentation of carbohydrates and nutrients. This fermentation is only possible due to the microorganism of the genus Lactobacillus. This fermentation also results in the production of formic and acetic acid.
Second synthetic method: In this method, The synthetic preparation of lactic acid takes place from carbon monoxide and acetaldehyde in acid solution. This takes place at a temperature of 130-200ºC.
乳酸的用途
- 乳酸在医学上用作静脉输液，在失血后作为等渗液进行复苏。
- 乳酸是生产各种聚合物的原料。
- 乳酸在食品工业中有广泛的用途，因为这种酸是一种很好的食品防腐剂和调味剂。
- 乳酸在化学工业中用于制造洗涤剂和诱蚊剂中很重要。
- 乳酸可以通过合成过程或发酵形成。后来涉及到氨基酸，维生素，肽，葡萄糖和盐等营养素的使用。所有这些营养物质都与微生物结合，微生物进一步利用营养物质释放乳酸。
- 乳酸在创伤性脑损伤的愈合中起着重要作用。大脑中去甲肾上腺素的释放由乳酸发出信号。
- 用于个人产品和保健产品。
- 它充当食品防腐剂。
- 它用于油漆和涂料添加剂，也用于家具护理产品。
- 它也用于纺织染色和皮革鞣制。
- 乳酸有助于牛奶中蛋白质的凝结。
示例问题
问题一：乳酸的分子式和IUPAC名称是什么？
回答：
The chemical formula C3H6O3. Its IUPAC name is 2-Hydroxypropanoic acid
问题二：乳酸对身体有什么作用？
回答：
In body, when oxygen level is low it requires the conversion glucose into energy, it makes lactic acid. This production of lactic acid can cause muscle pain, cramps and muscle fatigue. These type of symptoms are normal during physical exercise. After doing lots of physical activities or exercises, we often feel tired, fatigue, or even muscle cramps in our bodies. It is because of the accumulation of lactic acid in muscles, and When it reacts with extra oxygen that we inhale, breaking it into carbon dioxide and water. This lead to the break down of lactic acid as we get relief in cramps or muscle pain .
问题3：哪种食物含有乳酸？
回答：
Lactic acid is present in sour dairy products, such as yogurt, koumiss, kefir, laban, and some cottage cheese. When milk sugar (lactose) undergoes fermentation then the product obtained is lactic acid
问题4：乳酸的熔点和沸点是多少？
回答：
Boiling Point of Lactic Acid: 122°C
Melting Point of Lactic Acid: 16.8°C