Sulfur normally exists as an eight-atom molecule, S8, while phosphorus exists as a four-atom molecule, P4

TLS Online TPP Program

#Id: 10006

#XL - T Zoology

Hedgehog protein with autoproteolytic activity that cleaves off the C-terminus to reveal a signal sequence that marks the protein for secretion.

TLS Online TPP Program

#Id: 8136

#XL - Q Biochemistry

Golgi apparatus is a major site of carbohydrate synthesis, as well as a sorting and dispatching station for proteins products.

TLS Online TPP Program

#Id: 9297

#XL - S Microbiology

Nitrite reductase

Nitrite (NO2-) is a highly reactive, potentially toxic ion.

Plant cells immediately transport the nitrite into chloroplasts or plastids.

The enzyme nitrite reductase reduces nitrite to ammonium.

Leaf chloroplasts and root plastids contain different forms of nitrite reductase.

Each polypeptide contains two prosthetic groups, an iron-sulfur group and a specialized heme.

NO3-, high sucrose conc, and light induce the transcription of nitrite reductase mRNA.

Asparagine and glutamine repress the induction.

TLS Online TPP Program

#Id: 9095

#XL - T Zoology

TLS Online TPP Program

#Id: 9661

#XL - T Zoology

Activated RTKs and cytokine receptors promote PLCγ activity in two ways: 

By localizing PLCγ to the membrane

By phosphorylating PLCγ