steroid hormones/peptide hormones onset/standingwave

[km1865]

I came across a question the other day asking why steroid hormones have a delayed onset as compared to peptide hormones.. I thought the answer was becuase steroid hormones must diffuse through the nuclear membrane whereas peptide hormones would be quicker because they do not have to undergo this movment within the cell and can just start producing effects once they attach to their cell receptors... but the correct answer was it takes longer because the DNA must be transcribed/translated before it can produce its effects... however, isn't a combination of these two reasons generally why steriod hormones produce slower responses than peptide hormones... or is the movment through the nuclear membrane part wrong?

ALSO, this came up on an AAMC before, I know that to produce a standing wave two transverse waves must be travelling in opposite directions, however its not NECESSARILY true that their energy's should be the same to produce the standing wave right? In the AAMC question it just so happened that the energys were required to be the same BECAUSE the standing wave was m=1. (so basically its not always going to be the case that the two traveling waves have the same energy right)??

THANKS !

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[Phlame217]

I came across a question the other day asking why steroid hormones have a delayed onset as compared to peptide hormones.. I thought the answer was becuase steroid hormones must diffuse through the nuclear membrane whereas peptide hormones would be quicker because they do not have to undergo this movment within the cell and can just start producing effects once they attach to their cell receptors... but the correct answer was it takes longer because the DNA must be transcribed/translated before it can produce its effects... however, isn't a combination of these two reasons generally why steriod hormones produce slower responses than peptide hormones... or is the movment through the nuclear membrane part wrong?

ALSO, this came up on an AAMC before, I know that to produce a standing wave two transverse waves must be travelling in opposite directions, however its not NECESSARILY true that their energy's should be the same to produce the standing wave right? In the AAMC question it just so happened that the energys were required to be the same BECAUSE the standing wave was m=1. (so basically its not always going to be the case that the two traveling waves have the same energy right)??

THANKS !

I can answer the first but not the 2nd.

Most Peptide hormones are specific for the the surface receptors they target and therefore it triggers an intracellular cascade specific to the action of the given receptor to elicit such effects (i.e. phosphorylating a enzyme to turn it on, vice-a-versa, blah blah blah).

Most Steroid hormones have generalized effects for a tissue. They quickly diffuse across a membrane, so diffusion time has minimal effect. Upon binding a Intracellular receptor, a cascade is triggered to usually ends up in Transcription Factors being freed to enter the nucleus and bind various promotors to induce the transcription of many genes.

Therefore yes, it is purely the responsibility of having to make the products to carry out a given effect and not the binding time that determines overall effect time.

 

[km1865]

thanks dude.. can anyone answer the second question?

 

[km1865]

bump.. can anyone help me out on the second question about standing waves? thanks appreciate it!

 

[ScoobyDooo]

Edit: My mistake, I didn't see the first part of the question was answered.

I came across a question the other day asking why steroid hormones have a delayed onset as compared to peptide hormones.. I thought the answer was becuase steroid hormones must diffuse through the nuclear membrane whereas peptide hormones would be quicker because they do not have to undergo this movment within the cell and can just start producing effects once they attach to their cell receptors... but the correct answer was it takes longer because the DNA must be transcribed/translated before it can produce its effects... however, isn't a combination of these two reasons generally why steriod hormones produce slower responses than peptide hormones... or is the movment through the nuclear membrane part wrong?

The movement is correct as steroids are small and hydrophobic, so they can easily diffuse through biological membranes. They bind to cytoplasmic receptors and are carried to the nucleus where they regulate transcription. This is the slow process.

Can't answer the physics question sorry

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