When E2Fs are bound to Rb, not only are they transcriptionally inactive, but they also function to repress transcription by recruiting chromatin-modifying enzymes that promote deacetylation and methylation of specific histone lysines.

TLS Online TPP Program

#Id: 8313

#XL - Q Biochemistry

3 isoforms of actin-

α - expressed only in muscle cells

β and γ - found together in almost all non-muscle cells

TLS Online TPP Program

#Id: 10747

#XL - R Botany

Simple cyme (solitary)

Determinate inflorescence consist of a single flower, it may be terminal or axillary

Example: Hibiscus rosa-sinensis

TLS Online TPP Program

#Id: 9297

#XL - R Botany

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: 9268

#XL - Q Biochemistry

Nitrogenase is a complex consisting of the MoFe protein (dinitrogenase or component I) a heterotetramer, and the Fe protein (dinitrogenase reductase or component II) a homodimer.

TLS Online TPP Program

#Id: 7908

#XL - Q Biochemistry

In healthy mitochondria, PINK1 resides in the mitochondrial matrix.

In damaged or dysfunctional mitochondria, PINK1 resides on the outer mitochondrial membrane, where it recruits cytosolic Parkin.