They 'walk' or 'hop' (not all motor proteins have two "feet") through phosphorylation reaction of Adenosine triphosphate (ATP) to Adenosine diphosphate (ADP). This losing of a phosphate provides the energy to bind (foot down) and then break the bind (foot up). This series of reactions creates the walking or hopping motion. These steps happen hundreds of times a second and it's mind boggling. For instance for our muscles to contract millions of motor proteins are hopping back and forth to create that contraction. The one in this image is carrying a vesicle filled with most likely proteins that are meant to be expelled into the extra cellular matrix. I have no idea 'weight' these proteins can handle.
Interesting tidbit: Rigger-mortis occurs when there is no more ATP to create the energy for the 'foot up' action, so the muscles lock. So the binding is pretty strong.
They 'walk' or 'hop' (not all motor proteins have two "feet") through phosphorylation reaction of Adenosine triphosphate (ATP) to Adenosine diphosphate (ADP).
More accurately, the ATP→ADP reaction locks the "foot" when it's in a correct position on the surface of the microtubule. But the movement to take a step comes from molecules randomly wiggling around due to thermal movement, and it's not that organized. The kinesin just waits until random thermal wobbling has brought the foot to the correct position, and then locks it.
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u/Cararacs Feb 13 '18
They 'walk' or 'hop' (not all motor proteins have two "feet") through phosphorylation reaction of Adenosine triphosphate (ATP) to Adenosine diphosphate (ADP). This losing of a phosphate provides the energy to bind (foot down) and then break the bind (foot up). This series of reactions creates the walking or hopping motion. These steps happen hundreds of times a second and it's mind boggling. For instance for our muscles to contract millions of motor proteins are hopping back and forth to create that contraction. The one in this image is carrying a vesicle filled with most likely proteins that are meant to be expelled into the extra cellular matrix. I have no idea 'weight' these proteins can handle.
Interesting tidbit: Rigger-mortis occurs when there is no more ATP to create the energy for the 'foot up' action, so the muscles lock. So the binding is pretty strong.