During the mid- to late stages of seed development, specific mRNAs accumulate in embryos, These mRNAs encode so-called late-embryogenesis-abundant (LEA) proteins thought to be involved in desiccation tolerance. This mRNA accumulation in embryo at the time of high levels of which endogenous hormone?

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?