Nature's Incredible ROTATING MOTOR (It’s Electric!) - Smarter Every Day 300

Summary

In this 300th episode of Smarter Every Day, Destin explores the flagellar motor, a complex molecular machine found in bacteria. He meets with researchers at Vanderbilt University to understand how this motor, which propels bacteria, operates and its implications for biomechanics and the origin of life. The episode delves into the scientific process of imaging and modeling the motor at a molecular level, revealing the intricate structure and function of this biological marvel.

Takeaways

• 🎥 Destin, the host of Smarter Every Day, celebrates the 300th episode of his educational series.
• 🤖 Destin discovers an animation of a molecular motor called the flagellar motor, sparking his interest in its biomechanical implications.
• 🔬 The flagellar motor is a complex biological structure found in bacteria that helps them move, similar to a propeller on a submarine.
• 🏫 Destin visits Vanderbilt University to learn more about the flagellar motor from researchers who studied its molecular structure.
• 🧬 The flagellar motor operates on a proton gradient, using the energy from hydrogen ions to rotate and propel bacteria.
• 🔄 The motor can switch directions, which is crucial for bacteria's chemotaxis, the movement towards or away from chemicals in their environment.
• 🔍 High-resolution imaging techniques, such as cryo-electron microscopy, are used to visualize the motor's structure at the molecular level.
• 🧬🔧 The process of obtaining images of the motor involves transformation, expression, and purification of the protein components in E. Coli bacteria.
• 🤝 The collaboration between different scientific disciplines, such as biochemistry and microbiology, is essential for understanding the flagellar motor.
• 🤔 The complexity of the flagellar motor raises philosophical and scientific questions about the origin of life and the evolution of such intricate biological systems.
• 🌌 Destin encourages viewers to think critically about the existence and implications of the flagellar motor, regardless of their beliefs or affiliations.

Q & A

What is the significance of the 300th episode of Smarter Every Day mentioned in the script?

The 300th episode is a milestone for the Smarter Every Day series, indicating that it has been running for a considerable amount of time and has reached a significant number of episodes, which is a cool achievement for the host, Destin.

What is a flagellar motor and why is it significant?

A flagellar motor is a molecular machine found in certain bacteria that helps them move by spinning a whip-like structure called a flagellum. It is significant because of its complexity and the implications it has for biomechanics and the understanding of the origin of life.

How does the flagellar motor relate to the concept of chemotaxis?

The flagellar motor is integral to the process of chemotaxis, which is the movement of an organism in response to chemical stimuli. Bacteria use their flagellar motors to move towards favorable conditions or away from harmful ones, such as towards a food source or away from antibiotics.

What role does the protein CHeY play in the flagellar motor?

The protein CHeY acts as a sensor in the flagellar motor system. When the bacteria sense a need to move away from a location or towards a different one, CHeY binds to the motor and encourages it to turn in a clockwise direction.

How does the direction of the flagellar motor's rotation affect the movement of the bacteria?

When the motor rotates counterclockwise, the bacteria swim forward because the flagella form a bundle that acts like a single propeller. When it rotates clockwise, the bundle opens up, causing the bacteria to tumble and change direction, which is part of the chemotaxis process.

What is the process of creating a high-resolution image of the flagellar motor?

The process involves transformation (putting the instructions for the motor into E. Coli), expression (E. Coli making the motor), and purification (separating the motor from other cellular components). The purified motors are then flash frozen and viewed under a cryo-electron microscope to create high-resolution images.

How does the bacteria's flagellar motor system compare to a submarine in terms of design?

The bacteria's flagellar motor system can be compared to a submarine in that it has an outer protective layer similar to a submarine's hull, and it uses a propeller (flagellum) for movement and steering, similar to how a submarine uses its propellers.

What is the importance of the gradient of protons in the flagellar motor?

The gradient of protons, or hydrogen ions, across the bacterial membrane provides the electrochemical potential that the motor uses to generate movement. The protons flow from an area of high concentration to an area of low concentration, powering the rotation of the motor.

How does the shape of the flagella contribute to the bacteria's movement?

The flagella are shaped like a whip, and when they rotate, they create a thrusting force that propels the bacteria backward, allowing it to move forward. When multiple flagella rotate counterclockwise, they form a bundle that moves the bacteria in a straight line.

What is the role of the MOT-AB protein in the flagellar motor?

The MOT-AB protein forms part of the small gear within the flagellar motor. It interacts with protons or hydrogen ions, transferring them across the membrane and driving the rotation of the motor.

How does the high-resolution structure of the flagellar motor contribute to our understanding of it?

The high-resolution structure allows scientists to see each amino acid and how they interact with each other. This level of detail helps in understanding the motor's function, how it can change directions, and potentially how it could be targeted to disrupt bacterial movement.