An Introduction
Lactic acid, also known as lactate, is a chemical byproduct of anaerobic respiration. It refers to a process where cells produce energy without having oxygen around. Lactic acid gets produced in yoghurt by some bacteria. It is also present in your gut and blood. Your muscles and red blood cells often deposit the lactate into your blood. So, lactic acid is an organic one. It’s a chiral molecule, and it has two optical isomers, which are L-lactic acid and D-lactic acid. The presence of a carboxyl group adjacent to the hydroxyl group makes lactic acid an alpha-hydroxy acid. In this article, you can learn about lactic acid structure, its definition, uses, and sources.
What is Lactic Acid?
Lactic acid is one of the organic acids. The chemical formula of the lactic acid is C3H6O3. It has two optical isomers, Levo and Dextro, making itself a chiral molecule. L-isomers are commonly present among living organisms. The lactic acid has a significant part in various biochemical processes. It gets produced by the muscles during intense activity.
Lactic acid is soluble in water. It looks white in its solid-state and becomes colourless in the liquid state. Milk acid is another name of lactic acid. When lactose or milk sugar undergoes fermentation, the lactic acid gets produced. You can also find it in other dairy products like cottage cheese, yoghurt, etc.
Just so you know, a Swedish chemist, named Carl Wilhelm Scheele, isolated the lactic acid from milk for the first time in 1780. Also, the soluble salt of lactic acid, such as calcium lactate can act as a source of calcium. The PH of 1 mM of lactic acid is nearly 3.51. You can learn more about lactic acid as below.
Structure of Lactic Acid
Below you can find the structural representation of lactic acid or C3H6O3.
(Images to be added soon)
The extended formula of lactic acid is CH3CH(OH)CO2H, and it has a molar mass of 90.08 g/mol. Since a single carbon houses hydroxyl group (-OH) and carboxylic group (-COOH), the molecule gets classified as alpha-hydroxy acid. The central carbon is a chiral as it appears and the other two substituent groups are a hydrogen atom on a methyl group (-CH3). It results in two different structures: L-lactic acid (+) and D-lactic acid (-).
Properties of Lactic Acid
Lactic acid is colorless or yellow syrupy, during its liquid state. In solid form, you can find it in the white powder.
The molecular weight or molar mass of lactic acid is 90.08 g/mol. And it’s PH level is 3.51 per 1 mM of lactic acid.
The melting point of lactic acid is 530 Celsius, and the boiling point is 1220 Celsius. It is soluble in water and ethanol.
Lactic acid is corrosive to any metals and tissue. Thus, overuse and overconsumption of the lactic acid can come with severe side effects.
Uses of Lactic Acid
There are numerous lactic acid uses, and the first thing to note is that your body can produce lactic acid on its own. But, there is a significant requirement for industrially produced lactic acid. It can get formed using a synthetic process or fermentation. The latter involves usage of nutrients like amino acids, vitamins, peptides, glucose, and salt. These nutrients get combined with microbes, which further uses nutrients to give out lactic acid.
Once the lactic acid is ready, it can be used for various purposes as below.
Personal products and healthcare products
Food preservatives
Dairy products, like yoghurt
Cleaning, laundry, and dishwashing products
Paint and coating additives
Furniture care products
Textile dyeing and leather tanning
Pharmaceuticals
Applications of Acids and Basic Substances
Due to the different properties of acids and bases, they have a significant role in real-life applications. Some of the applications are-
Applications of Acid Substances
Citric acid is a key ingredient in lemons and oranges. Acids can also be utilized to preserve food.
Sulfuric acid is widely used in car batteries, which are commonly used to start the engines of automobiles.
Acids are used in the industrial production of explosives, dyes, and fertilizers.
Phosphoric acid is one of the key ingredients in many soft drinks.
Vinegar is a diluted form of acetic acid and it features several home applications like preserving food, etc.
Applications of Basic Substances
Ammonium hydroxide is one of the most important reagents used in laboratories.
Any extra acidity in the ground (soil), could be neutralized by utilizing slaked lime.
Ca(OH)2 (also known as slaked lime or calcium hydroxide) is used to make dust which is used for bleaching powder.
Calcium Hydroxide is used to make dry mixes which are utilized in design or artwork.
The production of soap and paper requires the utilization of salt (sodium hydroxide).
NaOH is utilized in the making of rayon.
Magnesium hydroxide(also referred to as milk of magnesia) is usually used as a laxative and it also decreases any extra acidity in a human's stomach. This property qualifies it to be an antacid.
FAQs on Lactic Acid
1. Which Food Contains Lactic Acid?
Lactic acid is present in a large amount of commonly consumed foods. It occurs in the food as a result of fermentation or in the form of an additive. You can find lactic acid in pickled vegetables, beer, wine, sourdough bread, kimchi, and fermented soy products like soy sauce. The lactate is also responsible for the tangy flavour in those food items. Apart from fermented vegetables and grains, fermented dairy foods like yoghurt contain lactic acid too. You can also find it in a large range of packaged products like spreads, bread, salad dressings, jams, olives, and desserts.
2. Why Does Lactic Acid Build-Up?
Lactic acid builds up in your body when there is inadequate oxygen in the muscles to produce energy. Typically, the muscles tend to break down glucose and glycogen to produce energy. It is an anaerobic metabolism. When your body moves, the body uses oxygen to get energy. During intense physical exercise or activity, there may not be ample oxygen available to complete the process. And then, a substance called lactic acid gets produced. And your body can convert the lactate into energy without needing any oxygen.
3. What Does Lactic Acid Do to Your Body?
When your body doesn’t receive enough oxygen to produce energy, then it makes lactic acid. It can cause a burning feeling in the muscles you are using. You may also feel pain in your muscles. Cramps and muscle fatigue are common when lactic acid builds up. Lactic acidosis, when caused by intense physical exercise, is often temporary. And you may face nausea, a weakness for a while. Keep in mind that all these symptoms are normal during physical activities. Since the liver is capable of breaking down any extra lactate, excess lactic acid is often not a problem.
4. What are Some Properties of Acids and Bases?
An acid is a chemical species capable of donating hydrogen ions to another substance. A base is a molecule that accepts electrons or releases hydroxide (OH-) ions in an aqueous solution. Acids and BAses have many different properties which also makes them useful in many areas. Some of the properties of Acids and Bases are-
Properties of Acids
Acids are corrosive substances.
They are good conductors of electricity.
Their pH values are always less than 7.
When reacted with metals, these substances produce hydrogen gas.
Acids taste sour.
For Example- Sulfuric acid [H2SO4], Hydrochloric acid [HCl], etc.
Properties of Bases
There are several properties shared by all bases.
A basic substance has a bitter taste and is slippery to feel.
It also dissolves in water, creating a solution of charged particles.
Bases are substances that are soluble in water and have a pH greater than 7(or a pOH less than 7).
They also contain OH- ions.
When dissolved in water, bases act as good conductors of electricity.
Bases taste bitter and turn red litmus paper blue.
Bases are usually alkaline with a pH greater than 7.
5. How to Study the Acids and Bases Chapter?
The chapter Acids and Bases is an important chapter of chemistry for students as it sets a base for other chapters in the subject and higher classes. To start the preparation of the chapter Acids and Bases for the best result, the student must go through NCERT twice and thrice and understand the fundamentals properly. The student should know the basic properties and applications of both acids and bases and should also understand the process of writing and balancing chemical equations. All the NCERT Exercises should be solved by the student first and then they can move onto worksheets and other reference books. Students can find NCERT Solutions of Acids and Bases and all other chapters at Vedantu's official website.
Students who need a revision or need their concepts to be cleared can check out Vedantu's official Youtube Channel where they'll find video lectures of the chapter Acid and Bases. Teachers make sure that they break down the topic to the simplest so that students who have doubts can clear it. Teachers also use questions and solve them in front of the students in live lectures so push the bell notification so that you don't miss the FREE and Live doubt clearing session on Acids and Bases or any chapter of any subject. On Vedantu's website, students will also find the list of important questions that are prepared by taking the exam's point of view as these questions cover most of the important topics that can be tested in tests or exams. Lastly, the student should solve previous year's questions as these will help them to break down the question pattern and help them study accordingly. Practising tests also creates an exam-like situation in which the student can prepare themselves to manage time and attempt with full focus. Students should use these FREE resources to get good marks in Acids and Bases. Students should remember that this chapter can be difficult for some of them but they should give it time and ask their teachers to explain them thoroughly as if this chapter is missed it can create problems in coming chapters of chemistry. Acid and Bases, as said, is an important chapter and students can easily master it with a little concentration and little hard work.
