Question

Which of the following is a property of motor proteins when their tails are bound together with their heads pointing in opposite directions?

1) The motor proteins can move relative to the cytoskeleton in both directions.
2) The motor protein complex exerts equal and opposite forces so it is stationary in the cell.
3) The oppositely facing motor heads both interact with the same microtubule or actin filament.
4) The motor protein complex moves relative to the cytoskeleton, while the cytoskeleton remains stationary.
5) The motor proteins can move relative to the cytoskeleton in only one direction.

Answer 1

The property of motor proteins with their tails bound together and heads facing opposite directions is that they exert equal and opposite forces and remain stationary in the cell due to the counteracting movements.

Step-by-step explanation:

Properties of Motor Proteins

When the tails of motor proteins are bound together with their heads pointing in opposite directions, several phenomena regarding cell motility and interaction with the cytoskeleton could be observed. However, the statement that best describes the property of motor proteins in this situation is that the motor protein complex exerts equal and opposite forces so it is stationary in the cell. This is because when motor proteins like dynein and kinesin face in opposite directions, they would effectively pull against each other, creating a situation where movement is balanced out and results in no net movement of the complex itself against the cytoskeleton.

Motor proteins are responsible for a variety of cellular movements, including the transport of vesicles, organelles, and other cargoes along microtubules. They utilize the energy from ATP hydrolysis to power these movements. For example, dynein facilitates the bending of axonemes in cilia and flagella, whereas kinesin typically moves cargo along microtubules in neurons. In the case of opposed motor proteins, this concerted activity is absent, leading to a stationary complex.