The Energetics of Protein Folding and Unfolding: A Detailed Explanation

  • Thread starter PremedBeauty
  • Start date
  • Tags
    Desperate
In summary: What does this mean? In summary, the main contribution of delta S to the free energy change will be positive. This means that breaking of favorable interactions holding the folded protein will require input of energy, and delta H will increase also.
  • #1
PremedBeauty
25
0
Desperate Need of Help!

I've done my homework (except one problem) and I want to make sure I am correct?

1. What is the sign (delta G) for the folding process? Unfolding? How do you know?
-(delta G) at low temp is positive and equilibrium will favor protein folding. At high temperature, delta G is negative and unfolding occurs because strong increase of change of entropy that lowers Gibbs free energy.

2. What is the sign for (delta S) “ “
-Unfolding (delta S) is positive and folding is negative because breaking of favorable interactions holding the folded protein will need input of energy , and delta H will increase also. When temperature increases, randomness increases and denaturation occurs at high temperature. Folding is in relation to decrease in randomness (at low temperature) and becomes more ordered.
3. What will contribution of delta S to the free energy change be positive or negative? What does this mean?

4. What are the main bonds and interactions that must be broken or disrupted is a folded polypetide is to be unfolded? Why does heat or ph cause unfolding?
-H-bonds, disulphide, salt bridges, and hydrophobic interactions are disrupted. If heat is added, vibrational modes in the molecule will be excited and will disrupt hydrophobic interactions and dipole-dipole interactions and denature protein. If ph were to change, the protonation state of amino and carboxyal groups change and ionic bonds in the proteins disrupt and disrupts salt-bridges.
 
Physics news on Phys.org
  • #2
Biochemistry is not my area, although I do find it fascinating. Nevertheless, I found this. http://en.wikipedia.org/wiki/Protein_folding
The essential fact of folding, however, remains that the amino acid sequence of each protein contains the information that specifies both the native structure and the pathway to attain that state: Folding is a spontaneous process. The passage of the folded state is mainly guided by Van der Waals forces and entropic contributions to the Gibbs free energy: an increase in entropy is achieved by moving the hydrophobic parts of the protein inwards, and the hydrophilic ones outwards. This endows surrounding water molecules with more degrees of freedom. During the folding process, the number of hydrogen bonds does not change appreciably, because for every internal hydrogen bond in the protein, a hydrogen bond of the unfolded protein with the aqueous medium has to be broken.
If a process if spontaneous, what is the sign on Gibbs free energy?

http://ocw.mit.edu/NR/rdonlyres/Health-Sciences-and-Technology/HST-508Fall-2005/2258C576-52A7-4492-A812-896F02EF46B6/0/lecture_st2.pdf pdf file.

http://www.cryst.bbk.ac.uk/PPS2/projects/day/TDayDiss/index.html

http://www.chembio.uoguelph.ca/educmat/phy456/456lec02.htm
 
Last edited by a moderator:
  • #3
Thank you very much!

Can you interpret question 3 for me?:
3. What will contribution of delta S (entropy) to the free energy change be positive or negative?
 

What exactly is "Desperate Need of Help"?

"Desperate Need of Help" is a phrase used to describe a situation in which someone is in urgent need of assistance or support. It can refer to a variety of different circumstances, such as a medical emergency, a financial crisis, or a personal struggle.

How can someone identify if they are in "Desperate Need of Help"?

It can be difficult to determine if someone is in "Desperate Need of Help" as each person's situation is unique. However, some signs to look out for include feeling overwhelmed, unable to cope with daily tasks, and experiencing extreme emotional distress or physical symptoms. It is important to reach out for help if you feel like you are struggling and cannot handle it on your own.

What should someone do if they are in "Desperate Need of Help"?

If you or someone you know is in "Desperate Need of Help", the first step is to reach out for support. This can include talking to a trusted family member or friend, seeking professional help from a therapist or doctor, or contacting a crisis hotline. It is important to remember that asking for help is not a sign of weakness, but a brave and necessary step towards getting the assistance you need.

What are some resources available for those in "Desperate Need of Help"?

There are various resources available for those in "Desperate Need of Help", depending on the specific situation. Some options include support groups, counseling services, financial assistance programs, and medical services. It is also helpful to reach out to local community organizations or charities for additional support and resources.

How can we help others who are in "Desperate Need of Help"?

There are many ways to help those in "Desperate Need of Help". You can offer emotional support by listening and being there for them, provide practical assistance such as helping with daily tasks, and connect them with resources and services that may be beneficial for their situation. It is also important to be non-judgmental and understanding of their struggles.

Similar threads

Replies
2
Views
5K
  • Biology and Chemistry Homework Help
Replies
3
Views
3K
  • Biology and Chemistry Homework Help
Replies
2
Views
2K
  • Thermodynamics
Replies
4
Views
12K
  • Biology and Medical
Replies
9
Views
21K
  • Classical Physics
Replies
8
Views
4K
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Thermodynamics
Replies
1
Views
1K
  • Advanced Physics Homework Help
Replies
1
Views
2K
  • Other Physics Topics
Replies
0
Views
737
Back
Top