KDC shows Divergent evolution, in which the genes for an enzyme with one substrate specificity give rise, during evolution, to closely related enzymes with different substrate specificities but the same enzymatic mechanism.

TLS Online TPP Program

#Id: 8369

#Unit 2. Cellular Organization

The length of the myosin II neck domain determines the rate of movement.

TLS Online TPP Program

#Id: 8370

#Unit 2. Cellular Organization

In the absence of ATP, the myosin head is firmly attached to the actin filament. 

TLS Online TPP Program

#Id: 8371

#Unit 2. Cellular Organization

In the presence of ATP,  myosin head releases from the actin filament. 

TLS Online TPP Program

#Id: 8372

#Unit 2. Cellular Organization

Thick-filament regulation

Myosin-dependent mechanism regulate contraction in smooth muscle and non-muscle cells.

TLS Online TPP Program

#Id: 8373

#Unit 2. Cellular Organization

In vertebrate smooth muscle, phosphorylation of the myosin regulatory light chain activates contraction in Ca2+ dependent manner.

TLS Online TPP Program

#Id: 8374

#Unit 2. Cellular Organization

When the Ca2+ levels drop:

Myosin LC is dephosphorylated by MLC phosphatase, causing muscle relaxation.