Mitogens and Apoptosis (video)

After watching this video it should be apparent what mitogens do and what apoptosis is.

In order to fully understand the mitogen response you need to understand the cell cycles and the signal transduction pathway. For both G protein receptors and Receptors with Tyrosine kinase domains I have the following videos:

As always if you want a private tutoring session with me, feel free to book an appointment and Id be happy to set something up!.

Blood Clotting (Hemostasis)

This post should provide you with all the information: both physiologically and biochemically needed to understand the clotting cascade and its many steps.

The clotting cascade is one of the most difficult things for students of medical physiology to learn. There are many different steps that require many different inputs to facilitate the phenomenon of blood clotting.

Note the many different types of input that initiate this process.

One of the most commonly asked questions when working with students is: Why so many steps?

Aside from the Evolutionary process that merged individual cells to whole communities and then organs and organ systems, clotting cascade is a great example of inter system interactions that optimize a process, in this case via amplification.

Still not clear ? have a question? Feel free to reach out to me via comments or book a private session today for 50% off.

How to solve optimization problems in Calculus (with video tutorial)

Calculus is usually the first time students are introduced to the field of optimization. Optimization problems are arguably the hardest aspect of undergraduate introductory calculus courses because they require you to extract information and relationships among variables given a set of initial conditions or a prompt. This makes it really hard because very few instructors take a methodical approach. Here are my recommended steps for solving optimization problems:

  1. Look at the equation to find the critical value/variable
  2. Look at the parameters/initial conditions/ whatever you are given and extract information and unknown relationships.
  3. Set up an equation that expresses your parameters as a single variable (critical value)
  4. Derive for the max/min.

Lets try a sample problem where a piece of paper is folded (x) in such a manner that it creates a crevice (L).. ( only a mathematician would think of this stuff…)

Our ultimate goal: express L in terms of X

There are three main relationships we can deduce from the picture given, ill call them triangles A B and C.

Since we need to define L in terms of X we have to first look at the expression for L, in triangle B

In order to express L in terms of X we need to find a way to express Z in terms of X, thankfully euclidean geometry uses linear scaling and proportionality, so we can observe that both Z and X are hypotenuses, therefore we can say they are equivalent, and from there using the heights given, express Z in terms of X., which we can use to express L in terms of X.

Next we want to clean up our expression to make the derivation of L as easy as possible.

now that we have defined L in terms of X all we have to do now is derive and solve for the absolute minimum value in this problem since it asks to have L as SMALL as possible.

Using the chain rule and the quotient rule, we can see that L = undefined when x = 0, 3/4ths of K and 1/2 of K.

Since X being zero would be impossible for the purposes of this problem given the prompt we can omit it and proceed using the same procedure for solving any optimization problem, namely finding out the values of L’ over intervals of the two remaining critical values.

In this example we tested the values for x using x = 2/3rds of K and x = K

Since the value of L’ goes from negative to positive X = 3/4ths of K is an absolute minimum and therefore the value we need to make L as small as possible.

Where does the 4th dimension in Kleibers Law come from? (video)

Fun fact not mentioned in the video: if you look at the distribution of the crinkles in the paper and compare it with the distribution of branching in your cardiovascular system we both see a fractal-like distribution

Calculating the initial pH of a titration using the Henderson-Hasslebach equation (Video).

Pretty straightforward problem here:

  • Find the change
  • Using the change and given the final, find the initial

Note: this is a great example of how we can use a dimensionless quantity to set up and assign units for it to translate an abstract ratio into an actual physical/chemical expression.

How do we classify primary protein structures? (Video)

From this video you should be able to identify primary protein structures. Which can be quite confusing at times, as it is an arbitrary and subjective man made classification system.

While we cannot predict the final 3D structure from the primary structure it is worth pointing out that we can model this phenomenon in a manner similar to weather forecasting ie with alot of homology, probability, and chaos. It is certainly worth pointing out that primary sequence is one of the most dominant variables that determines the finalized 3D form, but not the only one.

Students of complexity science and systems biology would want to take note:

When we have a unidirectional asymmetry in biology such as with protein N–C termini. The unidirectionality itself conveys information (asymmetry). As demonstrated by the two peptide chains having the same amino acid sequence but a different directionality, and therefore, different chemical properties. .