Mice homozygous for a null allele of dhh exhibit defective spermatogenesis

TLS Online TPP Program

#Id: 9870

#XL - R Botany

Upon absorbing UV-B photons, the tryptophans undergo structural changes that break the salt bridges, leading to the dissociation of the two functionally active monomers. The monomers then interact with COP1–SPA complexes to activate gene expression

TLS Online TPP Program

#Id: 9871

#XL - R Botany

The UVR8- COP1-SPA complex then activates the transcription of the major transcription factor HY5, which controls the expression of many of the genes induced by UV-B.

TLS Online TPP Program

#Id: 9035

#XL - T Zoology

Binding of the ligand to the receptor causes the receptor to change from an inactive conformation (R) to an active conformation (R*). Only the active R* conformation of the receptor can trigger the signal transduction pathway.

TLS Online TPP Program

#Id: 9036

#XL - T Zoology

The affinity of a signal molecule’s binding to its receptor is quantified by the dissociation constant for binding (Kd).

TLS Online TPP Program

#Id: 9037

#XL - T Zoology

A plot of the amount of ligand bound to the receptor

[RL] versus the amount of free ligand [L] called a

ligand-binding or saturation curve

TLS Online TPP Program

#Id: 9038

#XL - T Zoology

The levels of insulin present in the body and the Kd for binding of insulin to its receptor on liver cells,

1.4 × 10−10 M (0.14 nM). The normal concentration of insulin in the blood is  5 × 10−12 M. 

The fraction of insulin receptors with bound insulin, [RL]/[RT], at equilibrium as 0.0344