The temperature dependence of the solubilities of O2 and CO2 is such that at higher temperatures, the ratio of O2 to CO2 in solution increases. In addition, the affinity of rubisco for CO2 decreases with increasing temperature, exacerbating its tendency to catalyze the wasteful oxygenase reaction, favoring the oxygenase reaction.

TLS Online TPP Program

#Id: 9299

#Unit 4. Cell Communication and Cell Signaling

Rod cells sense light with the aid of a light-sensitive GPCR called rhodopsin.

TLS Online TPP Program

#Id: 9300

#Unit 4. Cell Communication and Cell Signaling

Rhodopsin has two components: 

Opsin protein, member of the GPCR A family 

11-cis-retinal light-absorbing pigment

TLS Online TPP Program

#Id: 9301

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9302

#Unit 4. Cell Communication and Cell Signaling

11-cis-retinal covalently attached to the amino group of lysine residue 296 in the opsin protein

TLS Online TPP Program

#Id: 9303

#Unit 4. Cell Communication and Cell Signaling

The heterotrimeric G protein coupled to rhodopsin, called transducin (Gt)

TLS Online TPP Program

#Id: 9304

#Unit 4. Cell Communication and Cell Signaling

In the absence of light,  bound 11-cis-retinal locks the rhodopsin into its inactive (R) conformation