Biochemistry Task 5
Brooke Storms ID # 000531395
January 24th, 2016
Triglycerides are made up of three fatty acids and one glyceride. The oxidation of these leads to ATP production, which will be explained in the following paragraphs. There are three main sources of fatty acids, the adipose tissue, the liver (in the form of VDL), and from the intestine (the food we eat). From these sources, it enters the blood stream and is distributed to the tissues. Once in the tissue, β Oxidation occurs. The long chain of fatty acid has a carboxylic group at one end. It is first broken down into two carbon subunits and then it generates Acetyl Co-A, which can then enter the Citric Acid Cycle. The electrons and the hydrogen are removed and carried by NADH and FADH2 to the Electron Transport Chain (O’Malley, 2014). The Citric Acid Cycle is also at work creating NADH and FADH2. The electrons and hydrogens released during this process from both β Oxidation and the Citric Acid Cycle move on to the Electron Transport Chain. Within this, the hydrogens are moving from a negative to a positive pressure and H20 is created. As it passes through the Electron Transport Chain ADP + organic Phosphate combine to create ATP, the cell’s energy (O’Malley, 2014).
A proton gradient is used to make ATP in the mitochondria during aerobic metabolism. The products of the Citric Acid Cycle, namely NADH and FADH2, are on the matrix side of the Electron Transport Chain. They each donate one electron to the proteins Complex I and II that are along the membrane between the matrix and the intermembrane. The donation of this electron also drops off the hydrogen ions, which then provides hydrogen on the matrix side to be pumped into the intermembrane side via the protein complexes. The two electrons that were donated are carried over to complex III via Coenzyme Q10. From there, the electrons are carried to Complex IV via Cytochrome C. The electron is then transferred to oxygen and forms H2O (Sanders, 2013). The energy from the electron transfers allow Complexes 1, 3, and 4 to pump hydrogen ions into the intermembrane space, which creates a surplus of hydrogen on that side. Since the concentration gradient of hydrogen is greater on that side, it gives it a positive charge while the other side has little or no charge (Wolfe, 2000). ATP Synthase acts as a dam and allows hydrogen ions to pass through to the matrix. The high energy of this transfer of hydrogen combined with ADP and phosphate creates ATP (Sanders, 2013). This process is referred to as oxidative phosphorylation.
There are several differences between saturated and unsaturated fatty acids. Saturated fatty acids are long, straight chains that only posses single bonds and are fully saturated with hydrogen. These occur mainly in animal fats. Unsaturated fatty acids have one or more double bonds and thus are not in a straight line. They usually occur in plants cells (Sanders, 2013).
The following diagram is a Saturated Fatty Acid:
As discussed previously, lipids are an important source of energy for our bodies. Lipids have many other functions as well. They work as messengers and help to start multiple chemical reactions that affect many aspects of metabolism. In the form of cholesterol, they surround every cell in our bodies. Another important role of lipids is help our bodies absorb Vitamins A, D, E, and K in the intestines (NIH).
It has been found that linolinc and linoleic acids are essential to our well being. These are both polyunsaturated fats, meaning they have multiple double bonds. The position of these bonds is what makes them essential. They are also referred to as Omega 3 and Omega 6 fatty acids due to the position of the bonds. Our bodies are not able to manufacture these essential fatty acids, so the only way that we can get them is through our diet (Neitzel, 2010).
The essential fatty acids discussed above are the starting molecules in prostaglandin. This is essential in many areas of our life, including regulating smooth muscle and blood pressure. Thromboxanes and leukotienes are two other very important signaling molecules made from the essential fatty acids. These three (including prostaglandin) are also referred to as eicosanoids. Almost every type of cell produces at least one of these. Their production is heavily regulated because they are so potent (Neitzel, 2010).
Completely avoiding dietary fat could be a fatal mistake. Besides not being able to absorb the fat soluble vitamins, you will alter your lipid based signaling systems. Since our body cannot synthesize the essential fatty acids, the important eicosanoid signaling systems would not be made without dietary fat. It would also decrease the effects of the signals. These signals regulate everything from blood clotting, to growth, to smooth muscle contraction, to blood pressure, and more (Neitzel, 2010). Without these regulating mechanisms, life cannot be sustained.
References
O'malley, M. (2014) Fatty acid oxidation leads to ATP production. Retrieved from https://wgu.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=0a7a8229-fcac-43a8-913e-16871f29545a
National Institute of General Medical Sciences. You Are What You Eat. Retrieved from https://publications.nigms.nih.gov/chemhealth/eat.htm
Neitzel, J. J. (2010) Fatty Acid Molecules: Fundamentals and Role in Signaling. Nature Education. Retrieved from http://www.nature.com/scitable/topicpage/fatty-acid-molecules-a-role-in-cell-14231940
Sanders, J. (2013) Fatty acid structure. Retrieved from http://wgu.hosted.panopto.com/Panopto/Pages/Viewer/Default.aspx?id=defcf97e-dd60-4de2-9055-d72a7e3334a3.
Wolfe, George (2000). Oxidative Phosphorylation. Retrieved from http://wgu.thinkwell.com/students/getResources.cfm?levelFourID=5869690&levelThreeID=1820596&levelTwoID=350662&mode=browse
