ulcerative colitis

Gas sample taken from the lumen of the large instestine of person suffering from the disease ulcerative colitis were founf to contain 100 times the level of NO as compared to those taken from controls. What does this tell you about the probable nature of the disease?

photoreceptors in the eye

Explain how rod cells adapt to changes in ambient light (from dark to hight light to very light) and the role of opsin phosporylation in the process.

cell signaling

If cell surface receptors can rapidly signal to the nucleus by activating latent gene regulatory proteins such as STAT's at the plasma membrane, why do most cell cell surface receptors use long, indirect signaling cascades to influence gene transcription in the nucleus?

ras proteins

You are given a mutant cell that lacks the GTPase activating protein. What abnormalities would one expect to find in the way that RAS activity responds to cellular signals? Please give concise answer. I dont need pages of copied textbook info. Thanks

tyrosine kinase

In a series of experiments, genes that code for mutant forms of a receptor tyrosine kinase are introduced into cells. The cells also express their own normal form of the receptor from their normal gene, although the mutant genes are constructed so that they are expressed at considerably higher concentrations than the normal gene. What would be the consequences of introducing a mutant genes that codes for a receptor tyrosine kinase which: a. lacks its extracellular domain b. lacks its intracellular domain