What is the role of blue light in terms of stomatal study?

a.) Blue light activates a proton-pumping ATPase in the guard cell plasma membrane and leading to stomatal opening

b.) blue-light stimulation lowers the pH of the apoplastic space surrounding the guard cells, and generates the driving force needed for ion uptake and stomatal opening

c.) The sensitivity of guard cells to blue light increases as a function of their zeaxanthin concentration

d.) npq1 mutant opens at higher fluence rates of blue light, whereas the phot1/phot2 mutant fails to show any blue light–stimulated opening

Which one of the following combination is correct?

TLS Online TPP Program

#Question id: 31036

#Unit 4. Cell Communication and Cell Signaling

In the resting, unstimulated (no ligand bound) state, the intrinsic kinase activity of an RTK is very low because:

Activation loop is not phosphorylated

Activation loop is phosphorylated

Phosphorylated loop prevents binding of substrate

Unphosphorylated loop prevents binding of substrate

Which of the following combination is incorrect?

TLS Online TPP Program

#Question id: 31037

#Unit 4. Cell Communication and Cell Signaling

In some receptors (e.g., the insulin receptor), unphosphorylated activation loop prevents:

TLS Online TPP Program

#Question id: 31038

#Unit 4. Cell Communication and Cell Signaling

For most, but not all, RTKs, the weakly active kinase in each subunit is thought to phosphorylate a key  residue, known as:

TLS Online TPP Program

#Question id: 31039

#Unit 4. Cell Communication and Cell Signaling

Phosphorylation of tyrosine in activation loop leads to a conformational change in the activation loop that unblocks the kinase active site for either ATP or the substrate by:

Reducing the Kd 

Increasing the Kd

Reducing the affinity

Increasing the affinity

Which of the following combination is correct?

TLS Online TPP Program

#Question id: 31040

#Unit 4. Cell Communication and Cell Signaling

HER3 is an EGF receptor that can bind ligands but lacks:

TLS Online TPP Program

#Question id: 31041

#Unit 4. Cell Communication and Cell Signaling

Which of the following statement is incorrect regarding HER2?