Chemistry - Essay 2

Tetanus
Summary
Tetanus is a rare disease that affects the central nervous system and causes painful contractions of the muscles.   Although tetanus is rare, it is fatal once the disease in contracted.   The tetanus bacterium is called Clostridium tetani and it e nters into the body via a cut that is exposed to contaminated soil, insect bites, burns, or any open wound. Tetanus bacteria multiply in contaminated wounds.   The bacteria release a toxin, called tetanospasmin, which is a neurotoxin that binds to inhibitory interneurons in the spinal cord.
Chemical Nature
The tetanus toxin, tetanospasmin, is a protein.
Chemical Structure of Tetanus Toxin
The tetanus toxin protein is translated from the TetX gene and is cleaved into two proteins, a heavy B-chain and a light A-chain. The chains are connected by a disulfide bond.
Mode of Action:
The interneurons that the toxin binds to are responsible for allowing contracted muscles to relax. They do this by stopping excitatory neurons from releasing acetylcholine that is responsible for muscle contraction. By blocking the release of inhibitors, the toxin keeps the involved muscles in a state of contraction.
Physiological effects of Tetanus
Once the body is infected with the tetanus bacteria, the patient can develop symptoms as soon as two days after or as late as one month. The first sign someone has contracted tetanus is usually muscle spasms in their jaw, which makes it very difficult for the patient to open and close their mouth, chew and swallow. This is why tetanus is also referred to as “lockjaw”. Once the patient has started experiencing spasms in the jaw and facial muscles, the toxin spreads to the rest of the body, causing muscle spasms in the arms, leg, stomach and back muscles. In an extreme case, the spasms will spread to the respiratory muscles and can cause suffocation which will lead to death.
Prevention of Contracting Tetanus
Tetanus can be easily prevented with a vaccine. Children are required to...