enzyme kinetics - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
USMLE Articles
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

Thread Tools Search this Thread Display Modes
Old 02-03-2012
doxorubicin's Avatar
USMLE Forums Guru
Steps History: 1+CK+CS+3
Posts: 391
Threads: 98
Thanked 160 Times in 98 Posts
Reputation: 170
Default enzyme kinetics

can anyone explain in simple language enzyme kinetics, km vmax and related graphs.
i never seem to get it.
if ur ready to learn......world is ready to teach...take d leap!!
Reply With Quote Quick reply to this message

Old 02-03-2012
USMLE Forums Scout
Steps History: Not yet
Posts: 94
Threads: 10
Thanked 23 Times in 19 Posts
Reputation: 33
Default hi

If you watch the videos of biochemistry this will help you alot

km substrate conc. required to produce half the maximum activity

and there is inverse relationship between KM and affinity

so if km high the affinity(activation) for subtrate is low because of that there

should be alot of subtrate conc. to do the effect.

there are two graphs michaelis-menten when km increase it will appear as

increase in x axis.

and km always will be Vmax divided by two.

in lineweaver-burk assume km was 1 then it increase to 2 so -.5 will be right

on x axis than -1

when km increase or decrease?this is in competitve inhibitor

ex. if there is drug work as competitive inhibitor you should increase the conc.

of subtrate due to decrease affinity so if conc. of subtrate increased it will

compete the drug.

Vmax number of enzyme and always related to word( induction) if there is

noncompetitve inhibitor(irreversible) so there is one or more site of enzymes

will lost so the result decrease in the number of enzymes this will appear on

Lineweaver-burk on the y axis as shifted upward why?assume if vmax was 2

then it decreased to 1 so .5 ahifted to 1 so increase.

And you should link this topic with pharmacology

hoping that I have simplified the concept,not complicated it .

waaaatch videos( Dr rayon in biochem).

good luck
Reply With Quote Quick reply to this message
The above post was thanked by:
doxorubicin (02-03-2012)


Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
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.
Where you live. Leave blank if you don't want to tell.


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
Glut Receptors; Zero & First Order Kinetics! indigo USMLE Step 1 Forum 2 12-17-2011 10:32 PM
Enzyme kinetics Q menatallah Elgohary USMLE Step 1 Forum 21 08-23-2011 05:41 AM
First Order Kinetics; How much of the drug will remain? yasirsattar75 USMLE Step 1 Forum 4 07-21-2011 07:33 AM
Which enzyme is increased? Farazdaq USMLE Step 1 Forum 5 02-26-2010 10:44 AM
Enzyme kinetics: competitive vs. non-competitive inhibition jackat1000 USMLE Step 1 Mnemonics 0 01-22-2010 09:15 AM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2016 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)