Connections to Past Knowledge - Part III - The 3 Themes That Bind

There were actually more than three. However, the "ties that bind", at least to me, are these:

• Amino Acids
• Nucleic Acids
• Metabolism

In terms of how they connect to more than one topic, it's actually more than that. Everything interconnects. Understanding how proteins form amino acids, which lead to the formation of nucleic acids - that are based on sugars - and how we are put together genetically, which further lead to how we utilize sugars to live, are what it has been all about.

In Biology 413 we were introduced to amino acids as well as the processes of transcription and translation. Exploring these themes further in this course was instrumental in understanding how we are formed, and much of what we learned is similar to learning a new language. In many ways, understanding how amino acids are used to form nucleic acids can be thought of as learning "the language of life."

Much of what I knew before I came was what I have learned through the training I received up through Paramedic school. I was certainly familiar with the TCA cycle, but not to the degree I learned it in this class. One thing that occurred to me is that knowing how we metabolize the glucose we utilize is important in understanding how Diabetes affects that cycle.

The way the concepts were taught in this class were almost linear. Buy they really weren't; they all came together. At least in my mind they did.

Overall, it occurs to me that the grade earned isn't as important as the understanding that the information we acquired in this class as well as the concepts we learned about. I will try to keep that in mind in the future.

Glucose - How We Use It

I had to think about how I would explain to someone how glucose is used in our bodies. It's actually not as complex as one would think, and I will make an attempt to explain it in terms that someone who hasn't studied Biochemistry might understand.

We ingest glucose. It is the basic unit of potential energy that our bodies use. It can be in the form of a plate of pasta, a peanut butter and jelly sandwich, or a bowl of pork fried rice. For that matter, most of the foods we consume contain glucose in some quantity. When we eat that food product that contains glucose, a number of things happen. First, there is an enzyme in our saliva - salivary amylase - which initiates the breakdown of glucose for further processing.

Once the glucose is broken down, it is absorbed into the bloodstream, causing the blood glucose level to rise and triggering the secretion of insulin from the pancreas. Cells that need glucose have specific receptors attached to them - insulin receptors - which encourages the glucose to enter and be used.

Inside the cells, ATP - adenosine triphosphate - is used within the cell to store and release energy. There are two ways which this is accomplished: either anaerobic metabolism (without oxygen), or aerobic metabolism (with oxygen). Anaerobic metabolism is inefficient and produces small amounts of energy as compared to aerobic metabolism, which produces considerably larger amounts of energy. It is oxygen used by aerobic metabolism that makes the difference in energy produced. This is accomplished through a cycle of processes known as the Citric Acid Cycle, where through a series of  chemical reactions involving products, chemicals known as substrates, and enzymes which transform a given substrate in the cycle to another substrate. Ultimately, the cycle makes its way back to converting back to Citrate, which is an intermediate that precedes Citric Acid. This is done in the mitochondria, or the part of the cell that is involved in generating energy.

Because of the amount of energy that is generated in this cycle, it continues until the energy source - glucose - is completely used up.