RAG1 is the predominant recombinase; it forms a complex with the RSS that is stabilized by the binding of RAG2.

RAG2 by itself does not exhibit detectable RSS binding activity

TLS Online TPP Program

#Id: 9307

#Unit 4. Cell Communication and Cell Signaling

A single activated rhodopsin protein activates 

~13 transducin molecules in the few seconds before the covalent bond between the opsin protein and all-trans-retinal is spontaneously cleaved

TLS Online TPP Program

#Id: 9308

#Unit 4. Cell Communication and Cell Signaling

RPE65 is the enzyme in the pigment epithelial cells of the retina that catalyzes the isomerization of the intermediate esterified all-trans retinol to 11-cis-retinol.

TLS Online TPP Program

#Id: 9309

#Unit 4. Cell Communication and Cell Signaling

Autosomal recessive mutations in the RPE65 gene are a frequent cause of blindness in children.

TLS Online TPP Program

#Id: 9310

#Unit 4. Cell Communication and Cell Signaling

In the dark, 

membrane potential of a rod cell is about −30 mV (Depolarized state)

Rod cells release neurotransmitters (glutamate) constantly

TLS Online TPP Program

#Id: 9311

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9312

#Unit 4. Cell Communication and Cell Signaling

Depolarized state of a resting rod cell is due to the presence of a large number of open nonselective ion channels that admit both Na+ & Ca²+ into the cell