The Golgi consists of four functionally distinct regions:

a. Cis compartments

b. Medial compartments

c. Trans compartments

d. Trans-Golgi network

TLS Online TPP Program

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#Unit 2. Cellular Organization

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

TLS Online TPP Program

#Id: 8386

#Unit 2. Cellular Organization

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

TLS Online TPP Program

#Id: 8387

#Unit 2. Cellular Organization

Thick-filament regulation

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

TLS Online TPP Program

#Id: 8388

#Unit 2. Cellular Organization

Smooth muscle cells and nonmuscle cells are regulated by:

Norepinephrine, angiotensin, endothelin, histamine

TLS Online TPP Program

#Id: 8389

#Unit 2. Cellular Organization

Smooth muscle contraction is regulated by the cycling of myosin II between on and off states.

TLS Online TPP Program

#Id: 8390

#Unit 2. Cellular Organization

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