Reflecting back on the course, what are three major themes you would identify that connect the various topics discussed in this course – how are they connected to more than one topic, and how do they connect with what you knew before this course? What knowledge have you gained with regards to these three themes you have identified?

As this course comes to a close if I had to choose three themes that connect the topics discussed in this class I would have to choose amino acids, enzymes and energy production. More specifically amino acids are molecules containing an amine group, a carboxylic acid group and a side chain that varies between different amino acids. As we have seen in this class amino acids, which are defined by a unique sequence of amine residues, play an essential role in our daily lives. They are most commonly thought of as being the building blocks of proteins. Specifically amino acids join together to form short polymer chains called peptides or longer chains called either polypeptides or proteins. These polymers are linear and unbranched, with each amino acid within the chain attached to two neighboring amino acids. The process of making proteins is called translation and involves the step-by-step addition of amino acids to a growing protein chain by a ribosome. The order in which the amino acids are added is read through the genetic code from an mRNA template, which is a RNA copy of one of the organism's genes. As is evidenced amino acids clearly play an integral role in not only biochemistry but genetics as well.


With regards to enzymes if there is anything that this class has taught us is that there is an infinite number of enzymes. Further, there can be any number of enzymes that catalyze a particular reaction with many reactions having one specific enzyme dedicated to it. For example the eighth step of glycolysis requires phosphoglycerate mutase in order for the reaction to occur. Further, by definition enzymes are proteins which speed up a chemical reaction by lowering the energy needed for the reaction to occur. Lastly, considering that enzymes are proteins and proteins are made up of chains of amino acids it is easy to see how they connect.

Finally, the production of energy has also been an important theme in this course as well. Most notably we spent several weeks examining mechanisms such as glycolysis, the citric acid cycle and the electron transport chain. All of these mechanisms are metabolic pathways that lead to the production of ATP which is the body’s primary energy source. Further, all of these cycles rely heavily upon the use of enzymes. If it wasn’t for enzymes the reactions in these pathways, which are endergonic meaning they are not thermodynamically favorably, would not occur on their own. Thus, enzymes which as I already noted are made of proteins, are truly necessary to ensure that the body is capable of producing energy.

Lastly, while the themes related to amino acids, enzymes and energy production were not altogether new to me this class certainly went into them in much greater detail than any of my previous classes. I was able to fill in a lot of gaps from previous classes regarding things such as the way enzymes bind using the induced model to gaining a greater understanding of how the steps on glycolysis work together to yield ATP. Finally what I appreciated most about this class was how it helped me to put all of these themes and concepts in perspective. In past classes enzymes or translation for example have always been taught one by one, almost as if they were being compartmentalized. Taking this class was refreshing as it allowed me to see how all of these processes work together.

How would you explain the connection between glucose entering the body and energy created by the body to a friend?

Glucose is the molecule our bodies use the most often to fuel our energy needs. The reason for this being that for many people a large portion of their diet is made up of carbohydrates. Glucose just happens to be a carbohydrate. More specifically glucose is a monosaccharide or simple sugar. Unfortunately, the carbohydrates that we eat are usually not simple sugars, but long chains of sugars known as polysaccharides. Thankfully we have something called salivary amylase or saliva in our mouths. Thus the minute we put food in our mouths the amylase begins the process of breaking down the food, both mechanically and chemically. Once a carbohydrate for example is broken down into glucose, glucose can then enter the metabolic pathway known as glycolysis.


Glycolysis occurs in the cytoplasm of cells in all living organisms, not just in humans. It is an anaerobic process that converts one molecule of glucose into two molecules of pyruvate. Although it would be wonderful if glycolysis was an instantaneous reaction it actually takes some time as the conversion of glucose to pyruvate requires ten separate steps which modify the glucose. These ten steps include several phosphorlyations, wherein a phosphate is added, as well as several isomerizations ,where the arrangement of the atom is merely altered. In spite of having to wait on these ten steps glycolysis is certainly worthwhile as it produces two molecules of ATP which can be used as energy for the body. It also yields two molecules of pyruvate which can then be sent on to other pathways such as the citric acid cycle, which in conjunction with the electron transport chain, can produce thirty two molecules of ATP. This ATP will certainly help our body to maintain normal functioning.