Antigens and Antibodies

Hi Everyone, 

        Let us continue our learning process. In this blog, we are going to learn about antigens and antibodies. We have already learned about pathogens.

 

        Well, pathogens are the infectious foreign microbes that cause diseases. The immune system persistently checks for foreign molecules. Once the foreign pathogens attack, the immune response is developed by white blood cells.  These white blood cells can differentiate their own cells and foreign cells by surface molecules. Foreign molecules that activate immune responses are called antigens. The surface of pathogens has different antigens which have different shapes. Moreover, different pathogens have different antigens. 

        White blood cells specifically B-lymphocytes produce antibodies when antigens attack the human body. Antibodies are Y-shaped protein molecules that recognizes specific antigens and bind with them in lock and key manner. These B-lymphocytes eliminate antigens and halt the infection.

Important points:

1. Since the antigens have different shapes, antibodies produced against one particular pathogen won't able to attack other pathogens.

2. Vaccine shots produce immunity by producing Antibodies against a particular pathogens.

Thank you!

References:

• What’s the Difference Between Antigens and Antibodies? (2021, March 4). Healthline. https://www.healthline.com/health/infection/antigen-vs-antibody

Pathogens

Here comes a brief elucidation about pathogens!

        Pathogens are the foreign infectious microbes that make you sick or cause disease. These are microscopic disease-causing agents from outside of our body which can spread from one person to another. Types of pathogens are,

• Virus
• Bacteria
• Parasite
• Fungi

But some of the above are harmless. Examples for beneficial bacteria are soil decomposers and bacteria in digestive system. Pathogens enter our body through nose, ear, mouth, eyes, any cut and any other openings to the body. Pathogens disrupt the normal functioning by using human body as host to replicate and infect others. Our immune system is designed to attack and abolish them. 

Some diseases caused by the pathogens are

• Viral diseases - flu, common cold, hepatitis, AIDS
• Bacterial diseases - Salmonella food poisoning, Strep throat, Tuberculosis
• Fungal diseases - Fungal nail infection, vaginal infections
• Diseases caused by parasites - malaria, intestinal worms

Thank you!

Enzymes

        Enzymes are the biological catalysts (also called biocatalysts) which accelerate the biological processes in living organisms. Enzyme lowers the activation energy of the reaction, hence speed up the reaction. Enzymes are must for the systematic functioning of biological processes such digestion, respiration, muscle activities, nerve function, excretion and few other metabolic activites. 

Enzymes are proteins which made up of one or more aminoacids. They react with the molecule called substrate and convert the substrate into products. Also, enzymes are highly specific in nature. 

Some examples of enzymes in human body are,

• Lactase - converts lactose into glucose and galactose
• Maltase - breaks down maltose into glucose
• Lactate dehydrogenase - converts lactate into pyruvate
• Rennin - converts milk proteins into peptides
• Protease - breaks down protein into amino acids

The enzymes has also got many industrial applications. Some examples are, 

• Amylase and protease - baking
• Rennin - cheese production
• Cellulase, protease, oxidases, amylase and peroxidase - detergent industry

Read more details about enzymes in the following book.

Enzymes

Thank you!

Milli-Q Water

Milli-Q water is water which is cleaned using ion exchange cartridge. The process involves consecutive steps of filtration and deionization (sometimes UV irradiation also) to acquire the desirable resistivity of 18.2 MΩ cm-1 at 25°C. As a final step, this water is flowed through 0.22µm membrane filter. Milli-Q is a brand, and it is the trademark created by the Millipore corporation.  Milli-Q water can be used in PCR, sequencing, blotting, 2-D electrophoresis, mammalian cell culture, MALDI-TOF MS etc. 

Distilled Water

What makes distilled water better than deionized water? Distilled water is water that is boiled and condensed back to the liquid form. This process is known as distillation. It separates all impurities like minerals, bacteria, some viruses, and other contaminants. The second and third time distillation of the once distilled water results in double and triple distilled water. Distilled water is used in car cooling systems, laboratory experiments, certain medical devices, watering plants etc. 

Deionized Water

Deionized water means water after removal of ions. This process is known as deionization/demineralization. Ion exchange resins are used to eliminate the undesirable cations and anions such as sodium, chlorides, sulphates, silicates, calcium, copper etc. and to process the purest form of water. This water is used for laboratory applications, industry processes, extinguishing fires, cooling applications etc.  

Nuclease-Free Water

Nuclease-free water means water free from both RNase and DNase enzymes. The presence of these enzymes can degrade the molecular samples. Methods of removing nucleases include treating with DEPC (diethylpyrocarbonate), filtration, and autoclaving.  Nuclease-free water is used in applications such as PCR, sequencing, cloning, cDNA synthesis and nucleic acid purification.