BC question

[shal630]

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Is urea a product of protein or non protein nitrogen metabolism found in urine?
and what about ammonia?
I am confused

 

[Sinatra Frank]

Is urea a product of protein or non protein nitrogen metabolism found in urine?
and what about ammonia?
I am confused

hi!
protein metabolism cam occur in 2 forms:

the amino group in the a"a of the protein can get coverted to urea in the liver and then secreted in the urin. or..the a"a can go to kidaney as glutamine and release direcly amonia to urin..
the reason why urea is formed is that amonia is too toxic to be circulated in the blood till the secretion occur.
btw..u can remember this fact by knoing that in liver cirhosis the conc of amonoia is sky high dut to failure of detoxification--> hepatic coma.

 

[shal630]

I got what you said but which is protein and which is non protein product.

 

[Sinatra Frank]

I got what you said but which is protein and which is non protein product.

both man..

in a catabolic state a protein is degraded to free a"as.. from there,the amino group of the a"a can be metabolized in the ways..urea cycle to give urea or in the kiney direct deamination of glutamine..

 

[shal630]

Ok then what will be answer for following question

The level of non protein nitrogen in the blood is due principally to the level of which of the following
a. urea
b. ammonia

Which main product of protein nitrogen metabolism is found in urine
a. urea
b. ammonia

How can both the answers be a

 

[shal630]

dietary iodine deficiency will increase the secretion of which of the following
a. thyroxine
b. thyroglobulin
c. triiodothyronine
d. TSH
answer is b. can anyone explain why?

 

[Sinatra Frank]

Ok then what will be answer for following question

The level of non protein nitrogen in the blood is due principally to the level of which of the following
a. urea
b. ammonia

Which main product of protein nitrogen metabolism is found in urine
a. urea
b. ammonia

How can both the answers be a

first of all both urea and amonia are termed as non protein nitrogen.
as u know..amonia is too toxic to circulate in the blood -->level of urea are higher.(1st question)
we said that there 2 mecanism to remove the amino group in a protein catabolism. the 1st in the liver,the urea cycle, is the main one.that is why u will find more urea in urin than amonia.

 

[Sinatra Frank]

dietary iodine deficiency will increase the secretion of which of the following
a. thyroxine
b. thyroglobulin
c. triiodothyronine
d. TSH
answer is b. can anyone explain why?

are u sure answer is B and not D? i thik there is mistake here.. when no iodine,less throid hormones are produced-->loss of negative feed back-->incrase TSH secretion-->casue endemic goitre.. i would chose D..

 

[njsmahal]

dietary iodine deficiency will increase the secretion of which of the following
a. thyroxine
b. thyroglobulin
c. triiodothyronine
d. TSH
answer is b. can anyone explain why?

if you see choices a and c require iodine for them so they are not the ones. not TSH is thyroid stimulating hormone so can be increased but the thyroglobulin is the prt that binds to iodine to produce a and c so if iodine is not present there would be increased b which has not combined hence the increase

 

[shal630]

that makes sense. Thanks

 

[Sinatra Frank]

if you see choices a and c require iodine for them so they are not the ones. not TSH is thyroid stimulating hormone so can be increased but the thyroglobulin is the prt that binds to iodine to produce a and c so if iodine is not present there would be increased b which has not combined hence the increase

sorry i cant understand from ur answer why not TSH?
We both agree that no T4 and T3 will be produced.hence no negative feedback--tsh wil be high and this is why endemic goiter occurs..i checked it over the robins book,,
as far as i know..thyroglubulin is not secreted from thyroid gland..
can u please explain urself..

 

[njsmahal]

sorry i cant understand from ur answer why not TSH?
We both agree that no T4 and T3 will be produced.hence no negative feedback--tsh wil be high and this is why endemic goiter occurs..i checked it over the robins book,,
as far as i know..thyroglubulin is not secreted from thyroid gland..
can u please explain urself..

thats why i said TSH can increase. and 1st they are not asking about secretion from the thyroid gland and secondly thyroglobulin is the protein that binds to iodine to form T3 and T4 so its secretion would be more than its use ... thats whta i think. do lemme know if you find anything

 

[Sinatra Frank]

thats why i said TSH can increase. and 1st they are not asking about secretion from the thyroid gland and secondly thyroglobulin is the protein that binds to iodine to form T3 and T4 so its secretion would be more than its use ... thats whta i think. do lemme know if you find anything

😀 i think we spent to much time on this question.. if u r intrested to know more.. type iodine defficency on google on go to emedecine website.. they give u there explanation on pathphysiology and lab analysis..
thyroglobulin was not mentined there..

 

[njsmahal]

😀 i think we spent to much time on this question.. if u r intrested to know more.. type iodine defficency on google on go to emedecine website.. they give u there explanation on pathphysiology and lab analysis..
thyroglobulin was not mentined there..

thyroglubulin is increased in goitre.

 

[njsmahal]

actually you know what... i was too into the scientific paper thing and maybe you are right... just checked wikipedia ....

 

[sania]

yeah frank is right,checked wikipdia too.so it says iodine binds to tyrosine in thyroglobulin molecule,so if idodine is not there, tyrosine will not bind ,it has nothing to do with thyrogloulin number,,,,,,,,,,,,,,,,,,,, Tsh will increase from negative feed back,

please correct me if i am using the wrong concept

yeah the point to note is that thygroglobin will increase in graves disease in throid cancer (from wkipedia,i love it,i am sure u all do)

thanks guys........



IT is produced by the thyroid epithelial cells, called thyrocytes, which form spherical follicles. Tg is secreted and stored in the follicular lumen.

Via a reaction with the enzyme thyroperoxidase, iodine is covalently bound to tyrosine residues in thyroglobulin molecules, forming monoiodotyrosine (MIT) and diiodotyrosine (DIT).

Thyroxine is produced by combining two moieties of DIT.
Triiodothyronine is produced by combining one molecule of MIT and one molecule of DIT

 

[Sinatra Frank]

yeah frank is right,checked wikipdia too.so it says iodine binds to tyrosine in thyroglobulin molecule,so if idodine is not there, tyrosine will not bind ,it has nothing to do with thyrogloulin number,,,,,,,,,,,,,,,,,,,, Tsh will increase from negative feed back,

please correct me if i am using the wrong concept

yeah the point to note is that thygroglobin will increase in graves disease in throid cancer (from wkipedia,i love it,i am sure u all do)

thanks guys........



IT is produced by the thyroid epithelial cells, called thyrocytes, which form spherical follicles. Tg is secreted and stored in the follicular lumen.

Via a reaction with the enzyme thyroperoxidase, iodine is covalently bound to tyrosine residues in thyroglobulin molecules, forming monoiodotyrosine (MIT) and diiodotyrosine (DIT).

Thyroxine is produced by combining two moieties of DIT.
Triiodothyronine is produced by combining one molecule of MIT and one molecule of DIT

tnx for ur input.. when r u guys taking ur exam? i have 4 weeks..and i still didnt touch on DA..

 

[njsmahal]

tnx for ur input.. when r u guys taking ur exam? i have 4 weeks..and i still didnt touch on DA..

i am giving exam in 10 days and scared as a freakin chicken in the tigers mouth if you know what i mean lol...what about you?

 

[Sinatra Frank]

i am giving exam in 10 days and scared as a freakin chicken in the tigers mouth if you know what i mean lol...what about you?

im doing it on mid september... i have the feeling i will have to retake it..
today i will finish pathology and still have DA..
i really fill that i dont know **** on anatomy and DA...

did u finish reading the material.? what is ur plan on the last 10?

 

[njsmahal]

im doing it on mid september... i have the feeling i will have to retake it..
today i will finish pathology and still have DA..
i really fill that i dont know **** on anatomy and DA...

did u finish reading the material.? what is ur plan on the last 10?

well ya i finished everything. have gone over kaplan and decks about 3-4 times now and done usmle first aid now doing it 3rd time. but its like i was doing questions and they were consuming alot of time and all were repeat and old so i dont know how much they will help out. so i went back to studying after getting disheartened once that i am not getting that high a score so i thought i would rather read some more and get things i dont know as much than to waste time on that. so i will give 2 days just ot papers to see if i need to do any topic and all i hope is i get a decent score that i get into some uni...

 

[Sinatra Frank]

well ya i finished everything. have gone over kaplan and decks about 3-4 times now and done usmle first aid now doing it 3rd time. but its like i was doing questions and they were consuming alot of time and all were repeat and old so i dont know how much they will help out. so i went back to studying after getting disheartened once that i am not getting that high a score so i thought i would rather read some more and get things i dont know as much than to waste time on that. so i will give 2 days just ot papers to see if i need to do any topic and all i hope is i get a decent score that i get into some uni...

looks like u really gave a lot of affort.. im sure ur hard work will pay off..
how much time did u study? which kaplan book did u use? the notes or eestential? keep in touch and keep up with the good work with answering people's problems 🙂

 

[njsmahal]

looks like u really gave a lot of affort.. im sure ur hard work will pay off..
how much time did u study? which kaplan book did u use? the notes or eestential? keep in touch and keep up with the good work with answering people's problems 🙂

well initially i studied for somewhere between 10-14 hours a day. been 2 and half months. but later now its just coming out to be just about 6-8. so thats the thing... and i did the book not the dentessentials. its fun to answer then we know what we are doing and how we are doing lol... and best of luck for you too. what have you done so far?

 

[Sinatra Frank]

well initially i studied for somewhere between 10-14 hours a day. been 2 and half months. but later now its just coming out to be just about 6-8. so thats the thing... and i did the book not the dentessentials. its fun to answer then we know what we are doing and how we are doing lol... and best of luck for you too. what have you done so far?

😀 u r so right! why do u think im entering this forum 10 times a day 🙂 much better to see other people problems,opinoin,scors etc..everything but studing.. i even read a thread on NBDE 2..

i start studing im mid june.. wasnt efficent is an undersatment..pure waste of time..just didnt study well.. now i am finishing pathology..tomoorrw ill do some question from kaplan and on sunday i plan to start DA..
im really afraid from this section,,how much time did u spend on it? do u think kaplan decks and first aid will be enough ? (im also working with kaplan lecture notes )

btw-in hematology section they didnt write anything on Anemias..starnge no?
im plannig to leave me 2 weeks for old exams and review once again the kaplan q's..
what do u think?
btw how is first aid for usmle in anatomy? worth readinf it"?

 

[njsmahal]

😀 u r so right! why do u think im entering this forum 10 times a day 🙂 much better to see other people problems,opinoin,scors etc..everything but studing.. i even read a thread on NBDE 2..

i start studing im mid june.. wasnt efficent is an undersatment..pure waste of time..just didnt study well.. now i am finishing pathology..tomoorrw ill do some question from kaplan and on sunday i plan to start DA..
im really afraid from this section,,how much time did u spend on it? do u think kaplan decks and first aid will be enough ? (im also working with kaplan lecture notes )

btw-in hematology section they didnt write anything on Anemias..starnge no?
im plannig to leave me 2 weeks for old exams and review once again the kaplan q's..
what do u think?
btw how is first aid for usmle in anatomy? worth readinf it"?

i gave DA about 9 days and about a week when i started to review and one or 2 days in between. for me what i saw was that decks and kaplan are ok but i dont know was difficult to understand there so just went through orbans just to have an idea and it was easier studying what i studied than kaplan. but for occlusion i did kaplan. and i liked usmle but its upto you if you like the way its given. and ya there is almost nothing about anemia... but i did it from usmle and they did a comparison. hopefully i get decent score to get into the colleges