Pls. answer this

[docapd]

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which of the following statements BEST describe GTP-binding proteins(G-Proteins)?
a.are important components of steroid harmone signal transduction
b.catalize the reaction which produces diacylglycerol
c.are tightly bound to adenylate cyclase
d.usually inactive protein kinase C
e.are membrane proteins
ans B which reaction is this???Could you pls. tellme?

Also,C and E are correct,rite??
GTP is present in cell membrane and it does bind tightly to adenylate cyclase
pls explain.
thanks
DOCAPD

 

[mulbery]

h

which of the following statements BEST describe GTP-binding proteins(G-Proteins)?
a.are important components of steroid harmone signal transduction
b.catalize the reaction which produces diacylglycerol
c.are tightly bound to adenylate cyclase
d.usually inactive protein kinase C
e.are membrane proteins
ans B which reaction is this???Could you pls. tellme?

Also,C and E are correct,rite??
GTP is present in cell membrane and it does bind tightly to adenylate cyclase
pls explain.
thanks
DOCAPD

i think the corrct answer is E .the question asks which statement best describes the GTP protein
yes i agree with u that GTP is an integral membrane protein .
remember stimulatory G protein consists of three subunits such as alpha,beta and gamma.
alpha contain GDP,the agonist -receptor triggers exchange of GDP for GTP on stimulatory G protein.so this alpha GTP activates the effector protein as adenyl cyclase.
hope this helps
please corect me if i am wrong

 

[rekhamadhuri]

h

i think the corrct answer is E .the question asks which statement best describes the GTP protein
yes i agree with u that GTP is an integral membrane protein .
remember stimulatory G protein consists of three subunits such as alpha,beta and gamma.
alpha contain GDP,the agonist -receptor triggers exchange of GDP for GTP on stimulatory G protein.so this alpha GTP activates the effector protein as adenyl cyclase.
hope this helps
please corect me if i am wrong

u r rite. gtp r membrane proteins

 

[mam6701e]

which of the following statements BEST describe GTP-binding proteins(G-Proteins)?
a.are important components of steroid harmone signal transduction
b.catalize the reaction which produces diacylglycerol
c.are tightly bound to adenylate cyclase
d.usually inactive protein kinase C
e.are membrane proteins
ans B which reaction is this???Could you pls. tellme?

Also,C and E are correct,rite??
GTP is present in cell membrane and it does bind tightly to adenylate cyclase
pls explain.
thanks
DOCAPD

These question refers to mechanism of water-soluble hormones, where there are 4 pathways to stimulate or inhibit any water-soluble hormone. These signal transduction paths are:
cAMP
PIP2
cGMP
Insuline and Growth factors (all this is in USMLE Kaplan notes)

Base on this
a). Cannot be cos…………..G prot are important components of water soluble hormone not steroid hormone signal transduction
b). Cannot be cos …………..even though G prot and DAG (diacylglycerol) are in the same signal transduction (PIP2); G prot activates phospholipase C enz and this enz divides the phospholipids that is found in the cell membrane into 2 second messengers: IP3 and DAG
d.) Cannot be cos………….G prtein activate Protein kinase trough 3 second messengers (Ca IP3 and DAG)


I wasn’t sure about the answer and that is why I though it is between c and e
c.) ………..cos I wasn’t sure if it is tightly bind to adenylate cyclase in the cAMP path and the other thing is that G protein not only activate adenyl cyclase, it activates phospholipase C and guanylate cyclase as well.
e.) even though it is located in the membrane in the 3 first pathways, but is located in the nucleus in the insulin path but as a monomeric compound

I asked to a USLME student and he says the answer is e cos the question refers to trimeric prot not to monomeric

 

[mulbery]

hi,
very good explantion

These question refers to mechanism of water-soluble hormones, where there are 4 pathways to stimulate or inhibit any water-soluble hormone. These signal transduction paths are:
cAMP
PIP2
cGMP
Insuline and Growth factors (all this is in USMLE Kaplan notes)

Base on this
a). Cannot be cos…………..G prot are important components of water soluble hormone not steroid hormone signal transduction
b). Cannot be cos …………..even though G prot and DAG (diacylglycerol) are in the same signal transduction (PIP2); G prot activates phospholipase C enz and this enz divides the phospholipids that is found in the cell membrane into 2 second messengers: IP3 and DAG
d.) Cannot be cos………….G prtein activate Protein kinase trough 3 second messengers (Ca IP3 and DAG)


I wasn’t sure about the answer and that is why I though it is between c and e
c.) ………..cos I wasn’t sure if it is tightly bind to adenylate cyclase in the cAMP path and the other thing is that G protein not only activate adenyl cyclase, it activates phospholipase C and guanylate cyclase as well.
e.) even though it is located in the membrane in the 3 first pathways, but is located in the nucleus in the insulin path but as a monomeric compound

I asked to a USLME student and he says the answer is e cos the question refers to trimeric prot not to monomeric

 

[docapd]

THANKYOU SO MUCH EVERYBODY FOR YOUR INPUTS.

BUT I DID NOT UNDERSTAND EXPLANATION b). Cannot be cos …………..even though G prot and DAG (diacylglycerol) are in the same signal transduction (PIP2); G prot activates phospholipase C enz and this enz divides the phospholipids that is found in the cell membrane into 2 second messengers: IP3 and DAG

COULD YOU PLS. EXPLAIN??????I'VE BEEN TRYING HARD TO UNDERSTAND.
SORRY IF I SOUND IGNORANT ......... 😕

 

[mam6701e]

THANKYOU SO MUCH EVERYBODY FOR YOUR INPUTS.

BUT I DID NOT UNDERSTAND EXPLANATION b). Cannot be cos …………..even though G prot and DAG (diacylglycerol) are in the same signal transduction (PIP2); G prot activates phospholipase C enz and this enz divides the phospholipids that is found in the cell membrane into 2 second messengers: IP3 and DAG

COULD YOU PLS. EXPLAIN??????I'VE BEEN TRYING HARD TO UNDERSTAND.
SORRY IF I SOUND IGNORANT ......... 😕

Why I am trying to say is that G prot does't work directly on diacylglycerol. There has to be one step first then cames diacylglycerol. Follow steps: 1) Membrame Receptor 2) G prot 3) phospholipase C enz 4) division of phospholipids that are found in the cell membrane into 2 second messengers: IP3 and DAG 5)IP3 makes Reticulum endoplasmatic to release Ca which is a third second messenger and then ........................sorry I dont remember I dont have the book with me right now.
But as I told you, try to get the biochem notes from USLME 1. It is very helpful.

 

[docapd]

Gee..........thanks a lot. i got it now.

Why I am trying to say is that G prot does't work directly on diacylglycerol. There has to be one step first then cames diacylglycerol. Follow steps: 1) Membrame Receptor 2) G prot 3) phospholipase C enz 4) division of phospholipids that are found in the cell membrane into 2 second messengers: IP3 and DAG 5)IP3 makes Reticulum endoplasmatic to release Ca which is a third second messenger and then ........................sorry I dont remember I dont have the book with me right now.
But as I told you, try to get the biochem notes from USLME 1. It is very helpful.

 

[mam6701e]

Gee..........thanks a lot. i got it now.

your welcome docapd

 

[mam6701e]

your welcome docapd

to reforce this answer, this are similar question with other alternative answer

http://forums.studentdoctor.net/showthread.php?t=212478&highlight=G-Proteins

Which of the following best describes GTP-binding (G-proteins)?

A. They are important components of steroid hormone signal transduction
B. They catalyze the reaction that produces diacylglyerol
C. They are lightly bound to adenylate cyclase
D. They usually inactivate protein kinase C
E. They are self inactivating--->answ

http://forums.studentdoctor.net/sho...highlight=steroid+hormone+signal+transduction

1. Which of the following best decribes GTP binding proteins.

a. component of steroid hormone signal transduction
b. catalyst reaction that produces diglycerol
c. bound to adenylate cyclase
d. they are self inactivating------------>answ
e. They usually activate protein kinase