GPK enzyme activity is increased either by phosphorylation of these two regulatory subunits by PKA or by Ca+2 binding to the calmodulin subunit; maximal activity requires both.

TLS Online TPP Program

#Id: 7923

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 7924

#Unit 2. Cellular Organization

Cardiolipin

an unusual “double” phospholipid containing four fatty acid chains

found primarily in the inner mitochondrial membrane

acts to improve the efficiency of oxidative phosphorylation, by restricting proton flow across the membrane

TLS Online TPP Program

#Id: 7925

#Unit 2. Cellular Organization

Endoplasmic reticulum

Network of interconnected membranous structures within the cytoplasm of eukaryotic cells contiguous with the outer nuclear envelope.

TLS Online TPP Program

#Id: 7926

#Unit 2. Cellular Organization

Rough ER, which is associated with ribosomes, functions in the synthesis and processing of secreted and membrane proteins

Smooth ER, which lacks ribosomes, functions in lipid synthesis.

TLS Online TPP Program

#Id: 7927

#Unit 2. Cellular Organization

Function of the ER:

most eukaryotic cells is to sequester Ca2+ from the cytosol (High concentration of Ca2+-binding proteins in the ER facilitates Ca2+ storage)

TLS Online TPP Program

#Id: 7928

#Unit 2. Cellular Organization

Muscle cells have an abundant, modified smooth ER called the sarcoplasmic reticulum.

The release and reuptake of Ca2+ by the sarcoplasmic reticulum trigger myofibril contraction and relaxation, respectively