The Chemistry of Snake Venom

Summary

The presentation delves into the chemistry of snake venom, highlighting its production in specialized glands and its role in prey immobilization, killing, digestion, and defense. It explains the composition of venom, including cytotoxins, neurotoxins, and hemotoxins, and its variability among snake species. The script addresses the importance of understanding venom chemistry due to the significant impact of snake bites, particularly in rural areas, and dispels common misconceptions about treatment. It also explores the creation of anti-venom and the potential medical applications of venom in treating conditions like epilepsy, asthma, and arthritis.

Takeaways

• 🌍 Snakes are found in every country except Antarctica, New Zealand, and Ireland.
• 🐍 Approximately 15% of snakes are venomous, belonging to three families: Elapidae, Atractaspididae, and Viperidae.
• 💧 Snake venom is a fluid produced by modified salivary glands, which can vary in color from clear to yellow.
• 🐉 Venom serves four primary purposes: immobilizing prey, killing prey, aiding digestion, and as a defense mechanism.
• 🔬 There are three main types of substances in venom: cytotoxins, neurotoxins, and hemotoxins, each with specific effects on cells and bodily functions.
• 🌐 Venom composition varies by species, with closely related species having similar venom makeup.
• 🧬 Snake venom contains 50-60 different types of proteins, including proteolytic enzymes, hyaluronidase, phospholipase A2, and L-amino acid oxidase.
• 🧪 Snake venom is acidic, with pH levels varying by species, contributing to its toxicity.
• 🏥 Snake bites affect millions annually, with significant consequences for rural populations in India and sub-Saharan Africa.
• 🚑 Common misconceptions about snake bites include ineffective treatments like sucking out venom or cutting the bite, which can be harmful.
• 🛡 Anti-venom is created by exposing horses to snake venom and harvesting their plasma, though alternative methods are being developed.

Q & A

Which countries do snakes inhabit, and which ones are exceptions?

Snakes inhabit every country in the world except for Antarctica, New Zealand, and Ireland.

What percentage of snakes are venomous, and how are they categorized?

Approximately 15% of all snakes are venomous and are categorized into three different families: Elapidae, Viperidae, and the Colubridae families.

What is snake venom and where is it produced?

Snake venom is a fluid created by modified salivary glands in a venomous snake's mouth, produced in glands located behind their eyes.

What are the primary purposes for the use of snake venom?

The primary purposes for snake venom are immobilization and killing of prey, aiding in digestion, and serving as a defense mechanism when the snake feels threatened.

What are the three main types of substances that snake venom contains?

The three main types of substances in snake venom are cytotoxins, neurotoxins, and hemotoxins.

How does venom aid in a snake's digestion?

Venom aids in digestion due to certain cytosines it contains, which help target and destroy cells, making it easier for the snake to digest its prey.

What are some common enzymes found in snake venom and what do they do?

Common enzymes in snake venom include proteolytic enzymes, which break down tissue, hyaluronidase, which enhances venom diffusion, phospholipase A2, a neurotoxin that disrupts biological membranes, and L-amino acid oxidase, which catalyzes the oxidation of amino acids.

Is snake venom an acid or a base, and how does its pH vary among species?

Snake venom is an acid, and its pH varies among species, with examples being a pH of 5.8 for Russell's viper and a pH of 6.6 for a cobra.

How many people are bitten by snakes annually, and what are the consequences?

On average, 4.5 million people are bitten annually, with 2.7 million having crippling injuries and around 100,000 deaths occurring due to snake bites.

What are some misconceptions about snake bites and the correct actions to take if bitten?

Common misconceptions include sucking out venom or cutting out the bite, which are unhelpful and can cause more harm. The correct action is to restrict movement in the affected area, keep the heart rate low, stay calm, and get to a hospital for anti-venom treatment.

How is anti-venom created, and are there alternative methods to traditional anti-venom production?

Traditionally, anti-venom is created by injecting horses with a gradually increasing dose of snake venom and then harvesting their plasma. An alternative method, developed by UC Irvine, involves synthesizing a polymer nanogel that binds to key protein toxins, preventing cell membrane damage.

How can snake venom be utilized for medical purposes, and what are some examples?

Snake venom can be used to treat various illnesses such as epilepsy, asthma, and arthritis due to some proteins in venom aiding nerve and muscle processes. For example, Russell's viper venom is a hemostatic agent that can prevent internal bleeding when diluted.