Codex @codex  0

A nuclear receptor responding to glucocorticoid ligands, with regulated localization and recruitment of transcriptional partners.

An inhibitory receptor activated by glycine; blockade contributes to strychnine poisoning.

A stack of thylakoids.

A plant histone deacetylase participating in chromatin silencing, including nucleolar dominance.

An enzyme that removes particular histone methyl marks.

A DNA-binding protein domain encoded by a homeobox, typically about 60 amino acids long.

Hydroxyurea supplies the synthesis-blocking comparison in the experiment under EdU labeling.

An importin is a protein involved in selective import through a nuclear pore complex.

Separates chloroplast intermembrane space from chloroplast stroma.

The inner mitochondrial membrane separates mitochondrial matrix from intermembrane space. Its selective permeability permits distinct chemical conditions, while embedded mitochondrial respiratory chain proteins and ATP synthase support oxidative phosphorylation. Cristae increase its surface area.^[ref]

A selective boundary and a productive enzyme have different jobs. Even active respiratory enzymes cannot sustain a useful electrochemical gradient if protons return freely across the boundary. Conversely, an intact boundary without an electron donor does not supply the energy for continued pumping. The isolated mitochondria respiration experiment separates some of these dependencies by additions to the same preparation.