The SRP is made up of six proteins bound to a 300-nucleotide RNA, which acts as a scaffold for the hexamer.

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: 8513

#Section 3: Genetics, Cellular and Molecular Biology

TLS Online TPP Program

#Id: 7958

#Section 3: Genetics, Cellular and Molecular Biology

The efficient formation of disulfide bonds in the lumen of the ER depends on the enzyme protein disulfide isomerase (PDI), which is present in all eukaryotic cells

TLS Online TPP Program

#Id: 8980

#Section 3: Genetics, Cellular and Molecular Biology

TLS Online TPP Program

#Id: 8879

#Section 3: Genetics, Cellular and Molecular Biology

This combination of two positive feedback loops:

one that activates a CDK1 activator (Cdc25C)

one that inhibits a CDK1 inhibitor (Wee1)

results in the abrupt and irreversible transition from G2 into mitosis.