G1/S phase CDKs phosphorylate Cdh1 at the 

G1-S phase transition

TLS Online TPP Program

#Id: 8406

#Section 3: Genetics, Cellular and Molecular Biology

Vertebrate skeletal muscle contraction, also depends on set of specialized accessory proteins that are closely associated with the actin thin filaments:

a) Tropomyosin

b) Troponin

TLS Online TPP Program

#Id: 8405

#Section 3: Genetics, Cellular and Molecular Biology

Muscle contraction depends on two processes that consume enormous amounts of ATP: 

1. Filament sliding, driven by the ATPase of the myosin

2. Ca2+ pumping, driven by the Ca2+ ATPase

TLS Online TPP Program

#Id: 8404

#Section 3: Genetics, Cellular and Molecular Biology

The increase in Ca2+ concentration is transient because the Ca2+ is rapidly pumped back into the SR by an abundant, Ca2+ ATPase.

TLS Online TPP Program

#Id: 8403

#Section 3: Genetics, Cellular and Molecular Biology

AP activates a  voltage gated Ca2+ channel in the T-tubule membrane, it triggers the opening of a Ca2+ -release channel in the closely associated SR membrane

TLS Online TPP Program

#Id: 8402

#Section 3: Genetics, Cellular and Molecular Biology

The arrival of a nerve impulse at a neuromuscular junction triggers an action potential in sarcolemma.

TLS Online TPP Program

#Id: 8400

#Section 3: Genetics, Cellular and Molecular Biology

In skeletal muscle cells, 

a low cytosolic Ca+2 level is maintained by a unique Ca+2 ATPase that continually pumps Ca+2 ions from

the cytosol containing the myofibrils into the SR, establishes a reservoir of Ca+2 in the SR.