Question about purine salvage pathway - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 11-20-2011
Dr. Mexito's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 662
Threads: 72
Thanked 369 Times in 204 Posts
Reputation: 379
Biochemistry Question about purine salvage pathway

Why is it that during the purine salvage pathway... we get hypoxanthine from AMP, and guanine from GMP?
Reply With Quote Quick reply to this message



  #2  
Old 11-20-2011
USMLE Forums Guru
 
Steps History: ---
Posts: 332
Threads: 48
Thanked 170 Times in 109 Posts
Default

Hypoxanthine is a spontaneous deamination product of adenine which is from adenosine monophosphate (AMP), guanine is from Guanosine Monophosphate (GMP).
Reply With Quote Quick reply to this message
  #3  
Old 11-22-2011
Dr. Mexito's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 662
Threads: 72
Thanked 369 Times in 204 Posts
Reputation: 379
Smile Maybe I did not asked in the correct way...

I was referring to the details of the reactions that lead to the production of hypoxanthine from AMP and guanine from GMP in the purine excretion and salvage pathways.

From AMP we get hypoxanthine because first, AMP looses its Pi becoming a nucleoside: adenosine (hypoxanthine + ribose). After this, by the action of the adenosine deaminase (ADA, the cause of SCID if not working well), adenosine will become a inosine after loosing its NH3, and then, by the action of purine nucleoside phosphorylase, inosine will loose its ribose-P resulting in only the hypoxanthine.

In the case of GMP, it only looses its Pi and its ribose-P, thus resulting only in a guanine that can now enter (Along with hypoxanthine), to either the purine excretion (10%) or purine salvage pathway (90%).
Reply With Quote Quick reply to this message



Reply

Tags
Biochemistry-

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
ABIM Research Pathway vkvimal IMG Residency Match Forum 0 08-11-2011 03:50 AM
My pathway to get 99/256 dr_smilingtears USMLE Step 1 Forum 10 04-01-2011 01:29 PM
My Pathway, Step 1 to Residency MedicalDR14 USMLE Step 1 Forum 28 01-24-2011 06:33 AM
Pathway towards Cardiac Surgery? saeyed IMG Residency Match Forum 3 12-25-2010 09:54 AM
Exclusive Mitochondrial Pathway? sam01 USMLE Step 1 Forum 6 04-29-2010 06:40 AM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)