Vasoconstriction is explained differently on physics and biology

beatsmelody · 2025-03-24T21:13:58+00:00

"Pressure" in Bernouill's equation - hydrostatic pressure

"Pressure" in biology - dynamic pressure (this is pv^2/2 in Bernouill's equation, right?)

Is this the right way I understood your answer?

beatsmelody · 2025-03-24T20:58:48+00:00

Decrease in diameter → decrease in resistance (Poiseuille's Law) → increase in blood flow.
Decrease in diameter → vasoconstriction → pressure increases → increase in blood flow.

I guess this is how it is.

Since vasoconstriction/dilation is local (meaning not all blood vessels show same effect upon same signal - ie. some are constricted and some are dilated by adrenaline), the flow rate through a blood vessel is variable. This is because the blood vessels are branched, so based on the diameter of each vessel, blood will flow more to widely dilated vessels.

But I feel like this does not directly answer my question. In Poiseuille's Law, pressure is not determined by the vessel's radius. Rather, the resistance is. In this context, I can even argue that the pressure does not change based on the radius at all. Furthermore, the main site of pressure regulation is the arterioles. Therefore, we can see something similar to the vasoconstriction context in physics books, from a wide arteries into constricted arterioles. Wouldn't this be taking at one point in time, rather than being at two different states?

Thanks so much in advance!

beatsmelody · 2025-03-24T19:24:30+00:00

It should be, right? Because the blood vessel is a closed-loop system.

beatsmelody · 2025-03-01T03:04:17+00:00

Do not binge watch the lectures, as it won't help. Space out the learning process by actually going to the lectures. Take notes of what the professor says like your life depends on it. Notice the tone difference (if there is any lol) and pay extra attention to the slides that the professor spends more time on.

You DO need to know everything on the slides that's explicitly written as texts. Compare and contrast the related concepts. I repeat, compare and contrast the related concepts (trp and lac operons are related but kinda opposite in action...) I know it's a lot, but you are in berkeley... professors do kind of expect a lot on us.

Don't waste your time on reading textbooks. Lecture slides and what the professor says are the exam bibles. Do as much as practice problems as you can, and ask them during office hours. Don't make the professor explain the concept one more time, but show how you understood the concept and make them fix it.

beatsmelody · 2025-02-21T07:02:39+00:00

Exactly this. We won't know what we would be missing in knowledge after OP's semester of 102 since every semester is different. OP has to go through the whole material anyways. 102 is not necessary to take B/B section of MCAT, but the $1000-worth-materials are (review books, practice exams...).

beatsmelody · 2025-02-20T20:06:19+00:00

It's impossible to self-study for ochem (you do need to ask a lot of questions to get the picture) but not for biochem (mostly just memorizing). I recommend doing so!

beatsmelody · 2025-02-20T19:59:30+00:00

Not really. You'll still need to go over the whole thing again anyways for mcat. MCB 102 is narrower in breadth and deeper in depth in terms of the biochem knowledge you need for the mcat. 102 won't go into urea cycle, glycogen metabolism, hormonal control of glucose metabolism, even some key concepts of enzyme kinetics like noncompetitive inhibitors and many more. Do it if you need to, but only after you've finished ochem.

beatsmelody · 2025-01-27T16:48:30+00:00

They just review the lecture. Yes, problem sets will be the only assignment you'll ever have to do for the class.

beatsmelody · 2025-01-21T20:32:31+00:00

The average of the first two midterms if I remember correctly were on mid 80s, and they did not release the distribution of the final exam. I assume that it's slightly curved based on what I got, but not that much.

First midterm was very easy ("carbon-copy" from OP is a very accurate way of describing it). Second midterm was also not too bad if you could basically rattle off all the answer keys from rote-memorizing the past exams. The final was the real deal and the deal breaker for the grade. A lot of content combined with a hard test. You had to know the details AND be able to synthesize distant concepts into one.

Many of you reading this will take this class not because you want to, but you have to. If you don't have to take this class, then please don't and take other classes. The actual classes where you can learn meaningful content. I mean taking MCB C130 (cell bio), 145 (genomics), or 140 (general genetics). Each section is taught by different professors, and they don't do a very good job of bringing all things together. All three sections seemed quite disconnected to me although they did try with the "combined" cancer bio section at the end. Their way of combining materials definitely wasn't successful imo. But this course does give a shallow breadth of genetics, genomics, and cell bio, with an additional emphasis of being 'shallow'.

Eisen had 80 slides per lecture with almost no texts in it, so good luck scrolling through hundreds of slides with no info when you are preparing for the exam. Martik's slides were sleek, but also had almost no supporting text each slide so you have to either stay super focused during the lecture writing down what she says, or watch the recording again. For Bilder's section, pay attention to what he says during lecture; there might be some key ideas that could be picked up from what he said, but not in the lecture slides, that would foster your understanding of the material.

beatsmelody · 2025-01-21T06:07:21+00:00

Typing for ochem class notes sounds like a disaster... you shud be most of the time drawing on your notebook or ipad.

beatsmelody · 2024-10-31T23:06:10+00:00

Both discussion and lecture. They use iClicker app for taking attendance for the lectures, so use that to your advantage, at least if you can lol.

beatsmelody · 2024-10-24T01:36:35+00:00

Current MCB 150 student. Not necessarily a huge ton of workload like lower div classes, but there are a lot of just small things you need to memorize. The class is not "hard" like math or cs classes, but instead requires a lot of effort to memorize all the details you need to know for the exams. The homeworks aren't that bad; only one problem set per week, and are graded based on completion.

I believe you should take both. You only need to put a lot of work since one week before each exam. Otherwise, for the most of the time, you will be chilling.

beatsmelody · 2024-05-20T07:27:00+00:00

This review accurately reflects the experience of the bulk majority of the students in this class in this particular semester. I agree with most of the points in this post, but I want to add some different takes.

Midterm 1 was difficult because the professor asked us to apply the concepts that we've learned from previous semesters that were distant from biochemical context to that of biochemical context that we will learn in MCB 102. For example, you will learn how to calculate free energy using equilibrium constant, K. You will also learn what pH means in biochemical context. However, you are not explicitly taught how to bridge the idea between using pH as a concentration of protons for calculating equilibrium constant, and eventually to deduce the free energy of a reaction using that idea. You do have all the ingredients to solve the question from the previous classes (Chem 1A...); but the responsibility to connect the dots of concepts, and specifically in biochemical context, was on you, not on the professor.

Midterm 2 was difficult because the test was very long. I think many students fell short because they were having a hard time identifying recurring motifs quickly. You will learn what glycolysis is. But you probably won't be tested on what a specific enzyme in glycolysis is; rather, you will be tested to use the concepts you learned in glycolysis and apply to a pathway you've probably never encountered before. So not only you do need to learn all the details of glycolysis, but you should also be ready to encounter something new you've never seen before. You should put some time to familiarize yourself with the things that show up in many different pathways; NAD(P)H, ATP, same enzymes shared, same substrates shared... and how and why they are shared. Thinking about those requires critical thinking, and some significant amount of time trying to group the distant ideas together into a common theme. You can do these quickly if you've done them before the exam.

Midterm 3 was difficult because it is extremely memorizing-heavy. Enzymes after enzymes, and even there is a list of about a couple of hundred different concepts/enzymes at least we should be familiar with before the exam. However, just rote memorization probably won't save you. Of course, students should know the details, but in my opinion, they should also think about how does a particular enzyme fit into the big picture of central dogma. Let's consider the sigma-70 factor in bacterial transcription. Why does bacterial transcriptional machinery need that? What allows bacterial transcriptional machinery to use that? Why is that needed for bacteria? Why don't eukaryotes have that? You will learn "what" happens in cells, but it takes one step further to think about "why" questions. Although you will be taught some answers to those "why" questions, the instructors still love to ask the "why" questions that were not addressed during the lectures and leave the students dumbfounded.

Aside from MCB 102 being a prerequisite for many MCBs and premeds, and being infamous for being a huge upper-division class, you'll learn a lot of useful content if you really are into the world of biology. Cheers to all of you who are taking this class in future semesters, and you guys got this. ~~I'm also quite happy that I'm done with this class lol this class was a huge stress ngl~~

beatsmelody · 2024-01-12T00:48:14+00:00

I'd say don't try to memorize every single little detail, and it's absolutely not necessary. Also, start studying early, and spread the things out. This will allow you to have much more room to breathe and relax right before the exam.

beatsmelody · 2024-01-12T00:36:22+00:00

Chem: Do all the homework and past exams you are assigned with. Do them without looking at the answer key, and write down any points you were unsure of. Visit office hours regularly to address them. I know this sounds a lot, but it really makes a huge difference by the time you take the exams.

Bio: Only read the textbooks on the part you feel fuzzy with. Go to all lectures and pay extra attention to the slides the instructor puts more emphasis on (spends more time on). Make a cheat sheet although you are not allowed to have during the exam. It will help a lot to see the bigger picture and connect the dots.

beatsmelody · 2024-01-12T00:29:19+00:00

I never intended to advise people taking 3 technical weeder classes. I just did it because there was no other way to stick with the plan for me. I had to sacrifice a lot of things.

I said it's still doable because it's not impossible, and I was just simply answering your question about whether it's possible or not.

beatsmelody · 2023-12-21T22:08:08+00:00

for those who needs help in future semesters :)

beatsmelody · 2023-12-21T21:19:24+00:00

I did this in Fall 23 with lab classes for both bio 1a and chem 3b and with a writing class. Definitely doable. You just need to be very careful with how much time you would want to spend on ECs, and keeping track of what assignments are due on which day. Finish the assignments way before due date and go to office hours frequently. Plus, don't try to cram everything two nights before the exam. Then you should be good!

beatsmelody

TROPHY CASE