Reflection

While having reflecting on three major topics studied during the semester in biochemistry and how they connect with the classroom discussion, I prepare to enter my semester end blog.
The question: How would you connect with the topics today, i.e. what did you know before the course? What have you learned about these three topics during the course?
The topics:
The steroid group
Sex hormones
The sodium/potassium pump
While discussing these three topics of interest, I will be leaning heavily upon the class text Biochemistry, by Campbell, Farrell & Shawn and PowerPoint class notes.
My knowledge for all three topics discussed below was on a very basic level. The knowledge of both structure and function was above my level of knowledge at the start of class in late January.
The first topic that I wish to discuss is the steroid group cholesterol, perhaps the most common, but least recognized as a steroid. Cholesterol is a critical steroid when it comes to the proper function of the human body. The primary structure is uniform, comprised of three (6) membered rings and a single (5) membered ring, followed by a carbon chain of varying lengths. Cholesterol serves as an important steroid, critical to the structural integrity of our cells. Cholesterols also serve as precursors to many other important biomolecules. Embedded in the Phospolipid bilayer, cholesterol add to the cell membranes rigidity and help to form bonds that firm up these basic but important cell wall structures and ultimately serve to give the body strength through a well-connected muscular undercarriage. Finally, it is important to mention that there are two forms of cholesterol HDL and LDL. HDL is high density, the “good” and LDL is low density or the “Bad” form.
Google to Blog Spot for a page on Cell wall: apbio82007.blogspot.com/.../cell-membrane.html
The sex hormones are arguably the next most common steroid group besides cholesterol, due to the important effects that they mediate and the fact that they are cholesterol derivatives and without regular intake of cholesterol from our diet, our bodies would have to expend drastic amounts of energy modifying other precursor molecules into essential hormones. They include, but are not limited to testosterone, estrogen and progesterone. These steroids are critical to normal function of primary sexual function as well as other various types of processes. These steroids follow the ring structure model listed above for cholesterol, the 6:6:6:5 ring fusion conformation, giving them steroid status, but have undergone various chain modifications to make them into specific sex hormones.
The second area of interest is the biomolecule the triacylglycerol group. These molecules are composed of three fatty acids and one glycerol molecule joined by three separate dehydration reactions, which forms an ester linkages between the fatty acids and the glycerol. These molecules are found in adipose tissue and carry a 2:1 ration for energy, when comparing a molecule of triacylglycerol to a carbohydrate or protein. These molecules are truly the fuel of humanity.

The third and final topic of reflection is the Potassium/Sodium pump. Specifically, the action of the three sodium molecules brought out of the typical human cell, the two Potassium molecules brought into the typical human cell, and the action potential given by one ATP or specifically one Phosphate atom’s bond energy to drive the reaction. Note: if the process is reversed, in response to a change in the direction of the gradient, although more rare, ATP is produced as a result. This is an example of a membrane protein within a cell changing conformation, in a number of different ways, at a number of different sites, to result in the correct substrates attaching to the correct areas and the complicated function of ion transport.
My take-away point for this semester is the newfound understanding of complexity when it comes to biomolecules and their roles in the workings of the human body. It may appear simple when looking at just one topic on its own, but as I have learned this semester, the synthesis of any number of systems with one another, describes a system of almost infinite complexity.

In all three cases, I have possessed a reasonably functional knowledge of the subject matter. The advantage of taking Biochemistry has been to tie in the working knowledge between these separate topics and thus advancing ones knowledge of the topics individually and collectively.
Thanks, Biochem you’re the best.
MCB