MCAT Biology: Top Study Strategies from a 528 Scorer

– Today, we'll discuss strategies for tackling the MCAT Biology
and Biochemistry section. The MCAT Biology/Biochemistry
section often includes the most experiment-based
passages on the exam, so it is important to be able to interpret figures, graphs, and tables. I'm Vikram Shaw, MCAT
expert and 528 MCAT scorer. In this video, I'll share
the exact strategies I used to ace the MCAT Biology
and Biochemistry section. I'll tell you what topics are on the exam, a formula for how to read
figures, graphs, and tables, and some helpful study tips you can use to improve your MCAT score. So, let's get started. What's actually on the
Biology/Biochemistry section of the MCAT? The MCAT Biology/Biochemistry section will test your knowledge of key concepts in the fields of Biology and Biochemistry as they relate to the human body.

Like the Chemistry/Physics and Psychology/Sociology
sections of the exam, the Biology/Biochemistry
section contains 59 questions that you must answer in 95 minutes. 44 of these questions
are based on 10 passages while 15 questions are standalone. The American Association of
Medical Colleges, or AAMC, writes the MCAT and they break down what's actually going to be on your exam. According to the AAMC, the Biology/Biochemistry
section of the MCAT is composed of 25% first
semester Biochemistry, 65% introductory Biology, 5% General Chemistry,
and 5% Organic Chemistry. You might be wondering, "What exact topics are covered
in each of these categories?" Topic number one is amino acids and the structure and
function of proteins. For example, do you
know what a ligase does? Topic number two is the
central dogma of Biology in which DNA is replicated to DNA, transcribed to RNA, and
translated into protein. Topic number three covers Genetics, such as mitosis, meiosis,
and Mendelian inheritance. A question may ask about the difference between mitosis and meiosis.

Topic number four covers metabolism, which includes topics such as glycolysis, gluconeogenesis,
the Krebs cycle, and the electron transport
chain, among others. Topic number six covers the
nervous and endocrine systems, and topic number seven covers
the structure and function of main organ systems such
as the kidney or liver. Many students worry that they
have not yet taken Physiology, and if that is the
case, you are not alone. Using the building blocks from your introductory undergraduate Biology class, you will be able to learn the level of detail tested on organ
systems for the MCAT. Now that you know what
you're gonna be tested on, let's go over tips and
study strategies you can use to score a 132 on the Biology
and Biochemistry section. MCAT Biology/Biochemistry Tip number one, practice interpreting
graphs, figures, and tables using the TAID P method. TAID P stands for title,
axes, independent variable, dependent variable, and patterns. If you can identify these elements in a graph, figure, or table, you'll be able to understand
what the data is telling you. Let's look at this example
using the TAID P method.

The title, T, states, "Effect
of Drug on Cell Survival." So, we can determine that the researchers are treating cells with a drug
and measuring cell survival. Now, let's look at the axes, or A. The x-axis shows increasing concentrations of drug in micromolar, while the y-axis measures
the percentage response, which we know from the title has something to do with survival. When we look at the graphs, the axes make it easy to determine the independent and dependent variables, which are I and D in the TAID P method.

First, what do the independent and dependent variables measure? The independent variable is something that you change on purpose while the dependent
variable is the response. The independent variable is
also shown on the x-axis, so we know here that drug concentration is our independent variable. The dependent variable, on the other hand, is shown on the y-axis, so we know that drug response
is our dependent variable. Finally, let's look at the patterns, or P, Are there any patterns in this curve? At what drug concentration do we see the greatest
percentage response? There seems to be a sharp transition between seven and eight micromolar in that drug concentrations above eight micromolar lead to
a favorable percent response. Now that we have completed this exercise, we are ready to approach any questions. You should aim to identify
the TAID P elements for any given figure
within 15 to 20 seconds. The goal is to understand the big picture without getting lost in any small details. The reason you should not spend too much time on any given figure during your first reading of the passage is that there may not even
be a question on that figure.

For example, if an MCAT
Biology/Biochemistry passage has three figures, they may only ask a
question about two of them, so you don't want to waste a minute understanding the figure in great detail if they're not even gonna
ask a question about it. So, how do you get faster at
applying the TAID P method? MCAT Biology/Biochemistry Tip number two, when you review a Bio/Biochem figure while going over your mistakes, study every small detail
of each figure carefully. Anytime you take an MCAT
Biology/Biochemistry passage that has a figure, you should come back after
you have submitted the answers and thoroughly review it
during your test review.

Why should you do this? By practicing applying the TAID P method under no time constraints, you will get better at being able to quickly and accurately
interpret figures. By the time you have completed several full-length practice exams, you will have taken almost a hundred MCAT Biology/Biochemistry
practice passages. If you spend the time to review the figures on each of those, there are very few figures that you will encounter on your MCAT that you would not have seen at least some variation of before. MCAT Biology/Biochemistry
Tip number three. Know the one-letter code,
three-letter code, structures, and chemical properties
of all 20 amino acids. This tip is one of the most
important tips you will receive as it is virtually guaranteed that you will see amino
acid questions on both the MCAT Biology/Biochemistry and Chemistry/Physics sections. It is not enough to
memorize the structures, but you should know what properties different structures
provide the amino acids. For example, would you be more
likely to see an arginine, which carries a positive charge, or a valine, which is hydrophobic, on the exterior of a protein.

The exterior of a protein is usually composed of
hydrophilic residues since it interacts with water, so we would be much more likely
to see the charged arginine, which can interact with water. Let's go through an example of an MCAT-style Biology
and Biochemistry question. Which of the following amino
acids is most likely located at the junction of two alpha
helices in a protein domain? A, proline, b, tryptophan,
c, serine, and d, glutamine. There are two amino acids that are known to introduce flexibility and
kinks into peptide chains. These are proline and glycine. We are likely to see an amino acid that changes the direction of the chain by introducing flexibility at the junction of two alpha helices, so answer choice a is correct. Notice that the question did not ask us what the structure of proline is, but rather it asked us to identify which amino acid side chain
has the necessary properties to be located at the junction
of two alpha helices. Let's now look at MCAT
Biology/Biochemistry Tip number four. Understand the integration of metabolism by focusing on rate limiting
steps and big picture ideas. Many students often
assume that they will need to memorize every enzyme,
reactant, product, and how to draw the reactants or products in metabolic pathways such as glycolysis.

Your time and effort,
however, is very valuable while studying for the MCAT and is probably better spent elsewhere on high-yield material. What is high yield from glycolysis? Instead of memorizing every
reactant, product, and enzyme, memorize the rate limiting enzymes that control movement through the pathway. What are the non-reversible
enzymes in glycolysis, and how does the body
regulate these enzymes in order to control our metabolism? Let's look at an example. Phosphofructokinase-1, or PFK-1, is the rate limiting step of glycolysis.

This means that the
entire glycolysis pathway can only move as quickly as PFK-1. Why does the body do this? Rate limiting steps are often very important regulatory
points within metabolism and biological pathways in general. Let's say we eat a large meal and have a lot of glucose
in our bloodstream. We want to process this glucose and either use it as immediate energy or store it for future use. In order to do this, we need
to carry out glycolysis. After we eat the large meal, insulin is also released
in our bloodstream. Insulin, through a series of steps, upregulates PFK-1 so that
it works more quickly, allowing glycolysis to
also occur more quickly. This is an example of the level at which you should understand
a given metabolic pathway. The metabolic pathways you should know are glycolysis, gluconeogenesis,
glycogenesis, glycogenolysis, Krebs cycle, electron transport
chain and ATP synthesis, fermentation, the pentose
phosphate pathway, fatty acid synthesis, and fatty acid oxidation
also known as beta-oxidation.

Finally, MCAT Biology/Biochemistry
Tip number five. Be familiar with experimental techniques. Experimental techniques on the MCAT Biology/Biochemistry
section include PCR, Western blot, Southern
blot, Northern blot, gel electrophoresis, SDS-PAGE and reducing gels versus
native gels, molecular cloning, and transformation,
conjugation, and transduction. You will encounter these techniques in Biology/Biochemistry passages and by applying strategies one and two, you will be able to work
your way through them. Here, we'll go over what each technique does at a high-level. So let's start with PCR.

This technique can amplify
small amounts of DNA and is useful in modern
applications such as sequencing or determining cellular mRNA levels. Western blot, this technique
measures protein levels in a sample using antibodies. Southern blot, this
technique detects DNA levels. Northern blot, this
technique detects RNA levels. Gel electrophoresis, this
technique separates molecules on the basis of size and charge. SDS-PAGE/reducing gels, this technique separates
denatured proteins on the basis of size. Native gels, this technique
separates proteins in their native conformation that allows subunits to remain intact. Molecular cloning, this technique is used to introduce genetic
information into a plasmid for protein expression
or genetic manipulation. Transformation, conjugation,
and transduction. These techniques are used to transfer genetic information
into bacterial species. And that's how to master the MCAT Biology and Biochemistry section. Now, you have a toolbox
of study strategies to attack your practice problems, so you can achieve your highest score on the MCAT Biology/Biochemistry section. If you found this video helpful, give it a thumbs up and subscribe, so you don't miss out on new videos. And if you'd like to receive a free MCAT question of the day, so you can get in every last bit of practice before test day, click the link in the description.

Thanks again for watching
and we'll see you next time!.

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