We use 70% Isopropyl Alcohol (IPA) instead of 100% because it is more effective at killing microorganisms. Pure alcohol evaporates too quickly to penetrate cell walls and denature proteins.
70% IPA has the right balance of water and alcohol, which allows it to stay on surfaceslonger, breaking down bacterial cell membranes more effectively
๐๐ผ๐ ๐ฑ๐ผ๐ฒ๐ ๐๐ฃ๐ ๐ฏ๐ฟ๐ฒ๐ฎ๐ธ ๐ฑ๐ผ๐๐ป ๐ฐ๐ฒ๐น๐น ๐๐ฎ๐น๐น๐?
Bacteria have a protective outer layer called the cell wall, which helps maintain their shape and protect them from their environment.
When 70% IPA comes into contact with the bacterial cell, it easily penetrates this wall. The water in the solution helps in this process by allowing IPA to pass through the cell membrane more effectively.
Once inside the cell, IPA interacts with the proteins and enzymes, which are essential for the bacteria’s survival.
Proteins are made up of long chains of amino acids folded into specific shapes that determine their function. IPA unfolds these proteins, rendering them nonfunctional. Think of it like unraveling a ball of yarn once the structure is lost, it can`t perform its job.
Denaturation is key because proteins control many critical processes in a bacterial cell, like metabolism, replication, and repairing damage. When these proteins are disrupted, the bacteria lose their ability to function and die.
Water plays a crucial role in the effectiveness of 70% IPA. Pure 100% IPA evaporates too quickly, meaning it doesnโt stay on the surface long enough to kill all the bacteria.
The presence of 30% water slows the evaporation rate, giving the alcohol more time to penetrate the bacterial cell wall and fully denature the proteins.
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๐จ๐ซ ๐๐ฑ๐๐ฆ๐ฉ๐ฅ๐:
Itโs like cooking an egg when you apply heat (IPA), the egg white (proteins) changes from clear to solid white, losing its original form. Similarly, when IPA interacts with bacterial proteins, they change structure, and the bacteria are effectively “cooked” and killed.