Down Syndrome and a biochemical bond? - 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 04-28-2012
DocSikorski's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,353
Threads: 94
Thanked 877 Times in 507 Posts
Reputation: 890
Biochemistry Down Syndrome and a biochemical bond?

Self made, watch out for mistakes
=====================

40 years old girl has all signs of down syndrome, however the extensive testing of this person's reveals that the trisomy occurred as a reason of a rare type of event that leads to this condition in less than 5% of cases. You examine her and notice that she has higher than expected IQ, ranging around 70. Her brother appears unaffected, and it was actually him to bring her to your visit, because he believes that she would get lost on her own, even if they live just 2 blocks away. He is sure about that because she did lose herself before recently in a common neighborhood. He states, that she started to forget things that she used commonly on a regular basis, became more irritable and this condition progresses everyday. Due to trisomy of one of the chromosomes, a substance with a particular structure is accumulated in the brain tissue of this person. What is the type of bonds connecting this structure?

a. ionic bonds.
b. metal-to-metal bonds
c. hydrogen bond
d. disulfide bond
e. noncovalent bond
f. resonance
g. hybridization

=============
its all for fun
__________________
Ambition is a dream with a V8 engine. EP
Reply With Quote Quick reply to this message
The above post was thanked by:
david khan (06-08-2012)



  #2  
Old 04-28-2012
Hope2Pass's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,684
Threads: 213
Thanked 1,600 Times in 660 Posts
Reputation: 1610
Default

I know this question is referring to APP precursor gene on chr 21 which leads to increased forms of Beta pleated sheets of amyloid protein in the brain. It gets accumulated because unlike alpha amyloid, this beta amyloid cannot be degraded down...so I'm guessing it's because it has really strong bonds?

I would go with c. hydrogen bonds
Reply With Quote Quick reply to this message
  #3  
Old 04-28-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 1,406
Threads: 118
Thanked 647 Times in 409 Posts
Reputation: 657
Default

APP-alzheimers
B-amyloid
what holds Beta sheets together? damn, i should know this.

I'll go with C. Hydrogen Bonds.
__________________
"inflammable means flammable!? What a country."
Reply With Quote Quick reply to this message
 
  #4  
Old 04-28-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 1,406
Threads: 118
Thanked 647 Times in 409 Posts
Reputation: 657
Default

Quote:
Originally Posted by Hope2Pass View Post
I know this question is referring to APP precursor gene on chr 21 which leads to increased forms of Beta pleated sheets of amyloid protein in the brain. It gets accumulated because unlike alpha amyloid, this beta amyloid cannot be degraded down...so I'm guessing it's because it has really strong bonds?

I would go with c. hydrogen bonds
actually hydrogen bonds are relatively weak. it's just that when there are a lot of them, the hold becomes tight. as in DNA.
__________________
"inflammable means flammable!? What a country."
Reply With Quote Quick reply to this message
  #5  
Old 04-28-2012
venky2600's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,186
Threads: 119
Thanked 821 Times in 434 Posts
Reputation: 831
Send a message via Yahoo to venky2600
Post

Quote:
Originally Posted by Dr.NickRiviera View Post
APP-alzheimers
B-amyloid
what holds Beta sheets together? damn, i should know this.

I'll go with C. Hydrogen Bonds.
ya dats true i'll go wid u
Reply With Quote Quick reply to this message
  #6  
Old 04-28-2012
Hope2Pass's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,684
Threads: 213
Thanked 1,600 Times in 660 Posts
Reputation: 1610
Default

Quote:
Originally Posted by Dr.NickRiviera View Post
actually hydrogen bonds are relatively weak. it's just that when there are a lot of them, the hold becomes tight. as in DNA.
yeah but when amyloid accumulates they form a relatively strong bond. Covalent and Disulfide bonds are the strongest bonds.
Reply With Quote Quick reply to this message
  #7  
Old 04-28-2012
Kabutar111's Avatar
USMLE Forums Guru
 
Steps History: Not yet
Posts: 414
Threads: 30
Thanked 87 Times in 70 Posts
Reputation: 97
Send a message via Skype™ to Kabutar111
Default

here i will be different a ionic bond
__________________
There is no shortcut to SUCCESS ,and there is no excuse for FALIURE - by Kabutar111
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message
  #8  
Old 04-29-2012
DocSikorski's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,353
Threads: 94
Thanked 877 Times in 507 Posts
Reputation: 890
Default

hydrogen bond is correct
__________________
Ambition is a dream with a V8 engine. EP
Reply With Quote Quick reply to this message
  #9  
Old 04-29-2012
Kabutar111's Avatar
USMLE Forums Guru
 
Steps History: Not yet
Posts: 414
Threads: 30
Thanked 87 Times in 70 Posts
Reputation: 97
Send a message via Skype™ to Kabutar111
Default

Quote:
Originally Posted by DocSikorski View Post
hydrogen bond is correct
And I m dumb,
Stick to basics is lesson
__________________
There is no shortcut to SUCCESS ,and there is no excuse for FALIURE - by Kabutar111
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message



Reply

Tags
Biochemistry-, Step-1-Questions, Syndromes-Acronyms

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
Indian Med Student to sign bond to return to India Thrax_usmle USMLE Step 1 Forum 1 04-24-2012 05:39 AM
Biochemical Abnormalities in Various Types of Rickets StepTaker USMLE Step 2 CK Bits & Pieces 5 12-19-2011 11:20 AM
Biotin as cofactor for which biochemical reactions! usmleman2020 USMLE Step 1 Forum 7 08-14-2011 06:00 AM
Mechanisms for biochemical abnormalities in postrenal ARF happy_philly USMLE Step 1 Forum 1 12-05-2010 07:37 PM
Biochemical Basis of this Scenario Yallah USMLE Step 1 Forum 3 04-19-2010 06:56 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)