Biology Forums - Study Force

Hey, my question was:

What specific cytoskeletal protein (or proteins) has its function altered as the ultimate effect of digitalis?

My thought was microtubule associated proteins but I wasn't sure of the specific one.

Thanks for any help!

Hey Faraz,

The ultimate effect of digitalis is to raise the blood pressure.

It does this by:

(1) Inhibiting Na+/ K+-ATPase
(2) This causes a rise in intracellular Na+
(3) Resulting in a less efficient Na+/Ca2+ ion exchange
(4) In turn, this results in an intracellular increase of Ca2+ => Finally, resulting in stronger contractions

Now here is the interesting part: high intracellular Ca2+ ions inhibits the assembly of microtubules - Alpha and Beta Tubulin cytoskeletal proteins (the major component of cytoplasmic microtubules) - and therefore, play a role in the regulation of microtuble formation.

So your answer should be tubulin (mention alpha and beta also)

Now it makes sense?  ::)

Thank you very much for the help! :)

I was also wondering anyone could help me answer this:

How is hydrogen peroxide used to convert ethanol into acetaldehyde in the peroxisome of liver cells?

You are life savers!

Hey faraz, we appreciate the questions, but next time start a new topic rather than continuing on with a solved one  :)

The enzyme catalase has also been shown to oxidize ethanol into acetaldehyde within the peroxisomes. This process is hydrogen peroxide (H2O2) dependent. However, under normal physiological conditions, catalase plays only a minor role in ethanol metabolism, but its contribution might be enhanced in the presence of higher amounts of hydrogen peroxide.

In the liver, the enzyme alcohol dehydrogenase oxidizes ethanol into acetaldehyde, which is then further oxidized into harmless acetic acid by acetaldehyde dehydrogenase. These two oxidation reactions are coupled with the reduction of NAD+ to NADH.

I hate chemistry but I love biochemistry  8)

oh and don't forget to contribute in the discussion section!