Cell Biology Essay Sample

Cell Biology

Adenosine triphosphate (ATP) is the energy rich compound found in all living cells. Each ATP molecule is made up of adenosine, an organic molecule. A single adenosine molecule has three inorganic phosphates attached to it. ATP is synthesized in mitochondria of cells from respiratory substrates (mainly glucose) in a process known as respiration. This process occurs in three stages- glycolysis, citric acid cycle, and electron transport.
The first stage, glycolysis, takes place in cytoplasm of a cell. In this stage glucose is split forming two molecules of 3-carbon molecule called pyruvic acid. This process does not need oxygen to occur. During glycolysis, two ATP molecules are released. In addition, two hydrogen ions are produced. These ions combine with a coenzyme referred to as Nicotinamide adenine dinucleotide (NAD) forming NADH2 (McArdle, Katch, & Katch, 2006).
Glycolysis is preceded by Krebs cycle which occurs only if oxygen is present. In this phase, pyruvic acid move into matrix of mitochondria where they are converted to Acetyl group, a 2-carbon molecule. This combines with Co-enzyme A molecules forming Acetyl Co-enzyme A which joins with a four-carbon molecule forming citric acid, a 6-carbon compound. Citric acid is further converted in enzyme-controlled reactions to five-carbon molecules ad thereafter to four-carbon molecules (Alcamo, 1998). The cycle also leads to release of two molecules of carbon (IV) oxide and hydrogen ions which are used in the electron transport stage.
In the last stage of respiration, hydrogen released in both glycolysis and Krebs cycle are picked up by NAD which then transport them as NADH2 to the cytochrome system in the cristae of mitochondria. In the cytochrome system, hydrogen electrons release energy (Woodward, 2013). The energy is used to synthesize adenosine triphosphate. At the end of this stage, hydrogen combines with oxygen in the forming water. The whole process, electron transport, leads to production of 34 energy rich compounds (ATP). Energy stored in ATP can be readily availed to the cells for processes such as contraction of muscles leading to movement, reproduction, and transmission of nerve impulses.
Some of the most common energy drinks include Red Bull and Impulse. The similarities in their adverts include the claims that they can enhance physical and mental performance and that they boost energy in the bodies. The notable difference in the adverts is that Red Bull indicates the drink can be used in any situation, improves performance in stressful and strenuous situations, and improves reaction speeds. These are not mentioned in Impulse adverts. Impulse’s adverts also feature energy sources the drink are obtained from, unlike Red Bull (Heidemann & Urquhart, 2005).
Energy drinks, for instance Red Bull and Impulse, contain sucrose and glucose in addition to other ingredients (Heidemann & Urquhart, 2005). Glucose is readily oxidised in the process of respiration to yield 38 ATP molecules, which provide the body with the needed energy. On the other hand, sucrose is first broken down to glucose and fructose and then later on broken down to give energy.
Despite the fact that most energy drinks contain glucose and sucrose which are sources of energy, they also have caffeine among other ingredients. Excessive consumption of caffeine has been associated with high blood pressure, insomnia, irritability, and nervousness. Therefore, I am against energy rinks and would rather recommend healthy consumption of carbohydrates as a source of energy.

References

Alcamo, E. I. (1998). Biology Coloring Workbook. New York, NY: Princeton Review Publishing
Heidemann, M. & Urquhart, G. (2005). A Can of Bull? Do Energy Drinks Really Provide a Source of Energy? Retrieved from http://sciencecases.lib.buffalo.edu/cs/collection/detail.asp?case_id=506&id=506
McArdle, W. D., Katch, F. I., Katch, V. L. (2006). Essentials of Exercise Physiology (3rd ed.)Baltimore, MD: Lippincott Williams & Wilkins
Woodward, D. (2013). Energy iii - cellular respiration (Krebs cycle and electron transport chain).Retrieved from https://wikispaces.psu.edu/pages/viewpage.action?pageId=137823250