Two BH3-only proteins, Puma and Noxa are transcriptionally induced by the p53 protein

TLS Online TPP Program

#Id: 8399

#Unit 2. Cellular Organization

The structure of the sarcomere is maintained by a number of accessory proteins: 

1. CapZ 

2.Tropomodulin

3.Titin 

4.Nebulin

TLS Online TPP Program

#Id: 8400

#Unit 2. Cellular Organization

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.

TLS Online TPP Program

#Id: 8402

#Unit 2. Cellular Organization

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

TLS Online TPP Program

#Id: 8403

#Unit 2. Cellular Organization

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: 8404

#Unit 2. Cellular Organization

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: 8405

#Unit 2. Cellular Organization

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