Indicate what type(s) of intermolecular forces are disrupted a...

Question

Indicate what type(s) of intermolecular forces are disrupted and what level of protein structure is changed by the following denaturing treatments:

c. egg whites whipped in a mixing bowl to make meringue

Accepted Answer

All right. Hello everyone. So this question is asking us to identify the type or types of intermolecular forces primarily affected and the level or levels of protein structure altered when eggs are scrambled with a fork before cooking. So here on the screen, we also have several different choices labeled A through D proposing different possible IMF s or intermolecular forces that could be disrupted. Now, some examples include ionic bonds, vander Waals forces hydrogen bonds and hydrophobic interactions. So first, let's go ahead and identify the types of intermolecular forces that hold proteins together because recall that proteins undergo several different levels of folding, which is why we talk about levels of protein structure, primary secondary, etc. And so across all of these levels of protein structure, we noticed that proteins are stabilized by hydrogen bonds but also forces such as ionic bonds, vander Waals interactions and also hydrophobic interactions. And so the question is which one of these is going to be interrupted by the scenario and the scenario in this case is the physical act of beating the eggs with a fork to scramble them before they are cooked. So we're not talking about cooking just yet rather we're talking about a mechanical force, right? Because we're talking about the scrambling of the egg. So that's a mechanical disruption. Now, scrambling the eggs of course, is going to disrupt the protein structure, but it's primarily going to disrupt hydrogen bonds. And the reason for this is because that mechanical force is going to bring these amino acids that are engaging in hydrogen bonds farther away from each other. Now, for the same reason, it's also going to disrupt the hydrophobic interactions because by disrupting the overall structure of the protein, what could also happen is that hydrophobic portions of the protein are exposed to air or maybe water. So now that we know what forces are being disrupted, what levels of protein structure are affected. So let's briefly go through all of them starting off with the primary structure. The primary structure, if you recall refers only to the sequence of amino acids making up the polypeptide. So it's covalent bonds making up this primary structure that is not likely to be affected by this mechanical disruption. On the other hand, secondary structure refers to hydrogen bonds between the atoms of the peptide bond pep bomb. And so secondary structure is most definitely going to be affected by this mechanical action, right, the scrambling of the eggs, but tertiary structure is a little bit more complex right. In that it's multiple different intermolecular forces between the amino acid side chains that make up this polypeptide. So unlike secondary structure, more than one intermolecular force is possible. But hydrogen bonds and hydrophobic interactions for that matter are both components of tertiary structure. So it's most definitely going to be affected too. Now, for ordinary structure, I very quickly just want to clarify that not all proteins have a co ordinary structure, co ordinary structure is only true of larger more complex proteins because co ordinary structure describes the interactions between sub units to create the protein complex. So here the same intermolecular forces that stabilize tertiary structure play a role in co ordinary structure. So it's going to be affected too and there you have it. So based on this, our answer is going to be option B in the multiple choice because the IMF s disrupted are hydrogen bonds and hydrophobic interactions and the secondary tertiary and Quain structures of the protein will be altered. So there you have it. And with that being said, thank you so very much for watching. And I hope you found this helpful.

Indicate what type(s) of intermolecular forces are disrupted and what level of protein structure is changed by the following denaturing treatments:
c. egg whites whipped in a mixing bowl to make meringue

Key Concepts

Intermolecular Forces

Protein Structure Levels

Denaturation

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