MCAT-Hydropathy index

[Foggybrain]

Hello everyone,
I came across an AAMC question pertaining to the concept of the hydropathy index, yet it is nowhere specifically stated in the AAMC content guide. Without coming across it in a question, I would not have known that it is a testable content. Just worried about other hidden topics. Thoughts? Thanks.

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[deleted936470]

A positive hydropathy index just means the amino acid is hydrophobic and is more likely found within a plasma membrane. Hopefully your biochemistry course covered this; that being said, vocab like this is very likely to be defined by the passage should it show up in a passage. If it's discrete, you should know that the peaks of a hydropathy graph correspond to transmembrane domains since high indices indicate hydrophobicity and low indicies are hydrophilic. For example, if there are 4 peaks then that means there are 4 transmembrane domains.
This is indeed listed under assemblies of molecules, cells, and groups of cells within singular cellular and multicellular organisms.
Hope this helps.

 

[Foggybrain]

A positive hydropathy index just means the amino acid is hydrophobic and is more likely found within a plasma membrane. Hopefully your biochemistry course covered this; that being said, vocab like this is very likely to be defined by the passage should it show up in a passage. If it's discrete, you should know that the peaks of a hydropathy graph correspond to transmembrane domains since high indices indicate hydrophobicity and low indicies are hydrophilic. For example, if there are 4 peaks then that means there are 4 transmembrane domains.
This is indeed listed under assemblies of molecules, cells, and groups of cells within singular cellular and multicellular organisms.
Hope this helps.

Thank you for the reply. I still cannot find it listed under "assemblies of molecules, cells, and groups of cells within singular cellular and multicellular organisms"? Where is it again?

 

[deleted936470]

Thank you for the reply. I still cannot find it listed under "assemblies of molecules, cells, and groups of cells within singular cellular and multicellular organisms"? Where is it again?

A table of contents does not typically contain the necessary vocabulary and really is just a list of the chapters or sections given at the front of a book. Even for psych, it is missing a significant amount of specific vocab or names that may show up on your test (e.g. rare psych terms).

Keep in mind that AAMC also asks questions on material that isn't in the study guide on purpose to see how you can manipulate new information in the context of an experimental passage (ex: novel/obscure chemistry experiments). Having everything on the content list down is a good start, but you need to move onto knocking out FLs. This exam will not spoon-feed you.

That particular BB section contains the concept of cell structure, which is completely related to hydrophobicity and hydrophilicity of amino acids. Also, AAMC flashcards are not a comprehensive list of topics and this is why I don't recommend the flashcards as they build false confidence and people are upset when they're not comprehensive; they are just high-yield concepts and vocab. Since the outline doesn't explicitly state know the vocab term "hydropathic index", in my experience, you should be able to gather what it is referring to by reading the passage/context in which it is mentioned. That is, this is likely to be explained by a passage and I'd bet it wouldn't be discrete.

That being said, get better used to ambiguity and AAMC forming questions about something you've learned in ways you've never seen before. Don't let reading the table of contents / using flashcards prevent you from digging deep into BB study resources, practice questions, and practical applications i.e. what type of research utilizes hydropathic indices. In my biochem courses, hydropathic index came up several times but never came up in my formal study.

Good luck!

 

[Foggybrain]

A table of contents does not typically contain the necessary vocabulary and really is just a list of the chapters or sections given at the front of a book. Even for psych, it is missing a significant amount of specific vocab or names that may show up on your test (e.g. rare psych terms).

Keep in mind that AAMC also asks questions on material that isn't in the study guide on purpose to see how you can manipulate new information in the context of an experimental passage (ex: novel/obscure chemistry experiments). Having everything on the content list down is a good start, but you need to move onto knocking out FLs. This exam will not spoon-feed you.

That particular BB section contains the concept of cell structure, which is completely related to hydrophobicity and hydrophilicity of amino acids. Also, AAMC flashcards are not a comprehensive list of topics and this is why I don't recommend the flashcards as they build false confidence and people are upset when they're not comprehensive; they are just high-yield concepts and vocab. Since the outline doesn't explicitly state know the vocab term "hydropathic index", in my experience, you should be able to gather what it is referring to by reading the passage/context in which it is mentioned. That is, this is likely to be explained by a passage and I'd bet it wouldn't be discrete.

That being said, get better used to ambiguity and AAMC forming questions about something you've learned in ways you've never seen before. Don't let reading the table of contents / using flashcards prevent you from digging deep into BB study resources, practice questions, and practical applications i.e. what type of research utilizes hydropathic indices. In my biochem courses, hydropathic index came up several times but never came up in my formal study.

Good luck!

Thank you for the post and for taking the time.

 

[JimKimSlim]

I had never heard of “hydropathy” before, and I worked in a biochemistry lab for three years. However, I was able to guess what it means by breaking it down: hydro = water & pathy = hate/avoid, so I knew it was related to hydrophobicity. It’s important to note that you don’t have to memorize or remember every single concept from your review book. Sometimes you gotta be able to piece together clues and come up with a plausible answer. On the real test, you’ll see lots of unfamiliar terms but you’ll be able to still answer them through careful reasoning, unless it’s a flat-out discrete question, like “what’s the wavelength of orange color light?”