Get this half-length for free with a free account at blueprintmcat.com. We are covering the second set of discrete questions in the bio/biochem section.
Listen to this podcast episode with the player above, or keep reading for the highlights and takeaway points.
Jason explains that the AAMC has divided the MCAT questions into different skill numbers. Skill 1 questions are the basic ones where it’s all content. Skill 2 questions are the more reasoning-based questions.
Skills 1 & 2 Levels in Discrete Questions
These two skills represent about 40% of all the questions that you’re going to see on your test. By and large, your discrete questions are going to be one of those two.
You’re also going to see Skill 2 in discrete questions where you’re asked to apply something that you know to a new situation. A lot of the psychosocial questions are going to do that. For example, they give you a vocabulary word, and you have to find out who is the person exemplifying that word.
Discrete questions are less scary.
Discrete questions are actually a little bit less scary because you never have to sit there and wonder if there was something relevant in the passage that you need to include. You don’t have to go back to a passage, scan for information, and worry about which part of the passage will provide the information.
Should you answer discrete questions first?
The rationale behind this question is that being able to get those quicker points helps build momentum and confidence. If you do easier questions first, they often go much more quickly than the more difficult questions. It gives you a better sense of your pacing once you finally go through the difficult questions as to how much time you have to spend on it.
But you don’t have a good way to find all the discrete questions just through the navigation page. You will have to click, say 59 questions before you can find the discrete sets, which is going to take more time than what you’re going to save in the long run.
[06:11] Question 29
Which of the following is most likely to use a protein channel to cross the eukaryotic cell membrane?
You could sit and make your flashcards and memorize all the different things that can go through the cell membrane, and approach it that way. This is what a lot of people do when they’re studying for this test.
The other direction to approach this is from a reasoning perspective. Think about what you know about cell membranes and what things can go through them and what can’t.
When you think of a cell membrane, think of a phospholipid bilayer. Hydrophobic and hydrophilic come up a ton on the MCAT.
So what’s going to be able to go through from one side of the cell membrane through the phospholipid bilayer and then out through the other side? The cell membrane has an aqueous environment while the phospholipid bilayer is that lipid in the middle that is a little bit more oily. And it’s also a little bit more hydrophobic.
Oxygen is small and it’s nonpolar. CO2 is small, and it’s nonpolar. Aldosterone is a little bit larger, but it’s a steroid hormone. Steroid hormones are basically cholesterol. So they’re happy to not only be incorporated into a cell membrane but also pass right through it.
Ions, on the other hand, are really going to hate that hydrophobic environment. Therefore, they need special channels or ways of getting through. Hence, B is the correct answer.
Correct Answer: B
[13:33] Question 30
Which of the following is an element of humoral immunity?
Answering this question comes down to familiarity with the different divisions of the immune system and being aware of the large pieces of each one. We don’t need to get down into the nitty-gritty of exactly how the immune system works for this question. We just need broad strokes, which is what the MCAt rewards.'The MCAT rewards a breadth of knowledge, not necessarily a depth of knowledge.'Click To Tweet
Phagocytes and T cells are more similar than they are different. They are part of the cell-mediated immune response, where those are actually the cells that are going out and doing the thing. MHC I and MHC II are the two kinds of proteins that will latch onto a pathogen that the T cells recognize and then attack. Therefore, all three of those are part of cell-mediated immunity.
Immunoglobulins are antibodies released by beta cells. So it’s not the beta cell that’s doing the immunity response.
Jason says that this is not flashcard knowledge. It’s taking that piece of knowledge that you’re trying to get and putting it on a hook in your brain. That really makes the difference.“If you can relate it to something you already know. You'll never forget it.”Click To Tweet
Correct Answer: B
[19:21] Question 31
A molecule enters a cell and creates pores in the inner mitochondrial membrane. Will oxidative phosphorylation continue to generate ATP?
A.Yes, because the cell membrane is still complete.
B.Yes, because ATP is required for cell function.
C.No, because there is no available oxygen.
D.No, because the proton gradient will be dissipated.
Thought Process:'The MCAT loves to take a system that works perfectly and break it and then ask you what happens.'Click To Tweet
If we dissipate the proton gradient, then we don’t get the electron transport that ultimately leads to ATP. So knowing that connection between the proton gradient and making ATP answers a lot of these kinds of questions for you. And you should expect to see a handful of questions on oxidative phosphorylation on your test.
Correct Answer: D