A bacterium lacking superoxide dismutase, catalase, and peroxidase - 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 06-02-2011
USMLE Forums Guru
 
Steps History: Not yet
Posts: 339
Threads: 94
Thanked 330 Times in 150 Posts
Reputation: 290
Bacteria A bacterium lacking superoxide dismutase, catalase, and peroxidase

A bacterium is examined and is found to lack superoxide dismutase, catalase, and peroxidase. Which of the following statements best describes this bacterium?

a. This bacterium is an anaerobe
b. This bacterium will survive in an oxygen environment
c. This bacterium is more virulent than one containing the three enzymes
d. This bacterium does not produce superoxide
e. This bacterium does not produce peroxide

Reply With Quote Quick reply to this message
The above post was thanked by:
justfree (06-04-2011), ranona77 (01-04-2013), star123 (06-03-2011)



  #2  
Old 06-02-2011
bebix's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,357
Threads: 194
Thanked 3,259 Times in 881 Posts
Reputation: 3269
Default

best describes?...This bacterium is an anaerobe?
Reply With Quote Quick reply to this message
  #3  
Old 06-02-2011
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,175
Threads: 38
Thanked 852 Times in 478 Posts
Reputation: 862
Default

Quote:
Originally Posted by bebix View Post
best describes?...This bacterium is an anaerobe?
Can't it also be: D) This bacterium does not produce peroxide

Because SOD is required to turn SOH into O2 & H2O2?

But then again, logically, why would the organism make something that's toxic to its own self
Reply With Quote Quick reply to this message
  #4  
Old 06-02-2011
USMLE Forums Scout
 
Steps History: Not yet
Posts: 71
Threads: 12
Thanked 60 Times in 23 Posts
Reputation: 70
Default

I'll go with A
Reply With Quote Quick reply to this message
  #5  
Old 06-02-2011
Claus_CU's Avatar
USMLE Forums Addict
 
Steps History: 1 + CS
Posts: 113
Threads: 8
Thanked 88 Times in 61 Posts
Reputation: 98
Default


A???
Reply With Quote Quick reply to this message
  #6  
Old 06-02-2011
pass7's Avatar
USMLE Forums Guru
 
Steps History: 1+CK+CS+3
Posts: 406
Threads: 30
Thanked 140 Times in 108 Posts
Reputation: 150
Default

This bacterium will survive in an oxygen enviornment, so B????
Reply With Quote Quick reply to this message
  #7  
Old 06-03-2011
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 149
Threads: 13
Thanked 46 Times in 34 Posts
Reputation: 56
Send a message via AIM to absolutjag9
Default

a i think...
Reply With Quote Quick reply to this message
  #8  
Old 06-03-2011
USMLE Forums Master
 
Steps History: Step 1 Only
Posts: 566
Threads: 25
Thanked 522 Times in 263 Posts
Reputation: 532
Default

I think is A.
Reply With Quote Quick reply to this message
  #9  
Old 06-03-2011
USMLE Forums Master
 
Steps History: Not yet
Posts: 674
Threads: 264
Thanked 959 Times in 393 Posts
Reputation: 969
Send a message via Yahoo to ricko335
Default

obligate anaerobes clostridia, methanogens, bacteroides laxk superoxide dismutase, catalase and peroxidase
answer is a

http://www.textbookofbacteriology.net/nutgro_4.html
check the link for d answer its given good
Reply With Quote Quick reply to this message
The above post was thanked by:
star123 (06-03-2011)
  #10  
Old 06-03-2011
USMLE Forums Scout
 
Steps History: Not yet
Posts: 17
Threads: 2
Thanked 4 Times in 3 Posts
Reputation: 14
Default

I think its A.
Reply With Quote Quick reply to this message
  #11  
Old 06-03-2011
USMLE Forums Veteran
 
Steps History: ---
Posts: 250
Threads: 19
Thanked 43 Times in 39 Posts
Reputation: 53
Default

definitely a
Reply With Quote Quick reply to this message
  #12  
Old 06-04-2011
USMLE Forums Scout
 
Steps History: CS Only
Posts: 25
Threads: 0
Thanked 21 Times in 16 Posts
Reputation: 31
Default

Quote:
Originally Posted by earthpole View Post
A bacterium is examined and is found to lack superoxide dismutase, catalase, and peroxidase. Which of the following statements best describes this bacterium?

a. This bacterium is an anaerobe
b. This bacterium will survive in an oxygen environment
c. This bacterium is more virulent than one containing the three enzymes
d. This bacterium does not produce superoxide
e. This bacterium does not produce peroxide

waiting for the right answer...
Reply With Quote Quick reply to this message
  #13  
Old 06-04-2011
USMLE Forums Scout
 
Steps History: Not yet
Posts: 21
Threads: 1
Thanked 16 Times in 13 Posts
Reputation: 26
Default

Here is the right answer (PreTest)

The answer is a. Superoxide dismutase is an enzyme found in both prokaryotic and eukaryotic cells that can survive in an envi- ronment of O2. Lack of this enzyme as well as peroxidase and catalase insures that a bacterium will not grow in the presence of O2. Absence of these enzymes is not related to virulence, although ability to survive in an O2-rich atmosphere may impart certain benefits to the proliferation of bac- teria in the human host.
Reply With Quote Quick reply to this message
The above post was thanked by:
Claus_CU (06-05-2011)



Reply

Tags
Microbiology-, Step-1-Questions

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
Catalase Positive Microorganisms Betro Sadek USMLE Step 1 Mnemonics 8 1 Week Ago 02:37 AM
ALS and superoxide dismutase gene SOD1 doctorF USMLE Step 1 Forum 8 04-01-2010 01:51 PM

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)