Cancer cells are characterized by unlimited cell growth, inefficient apoptosis and excessive anabolism. The process of becoming cancer cells includes gene activation, micro-environmental changes and metabolic reprogramming. All of which compound upon one another and lead the cancer cells to continue with their overwhelming growth and activity. Malignant cancer cells invade and destroy organ infrastructure and replace it with disorganized and damaging cells. (1) The metabolic preference of cancer cells is wide ranging with cervical and glioma cells maintaining a normal oxidative phosphorylation and others exhibiting the switch to glycolysis. (2) This metabolic switch exhibits the adaptation to environmental changes and the tumor’s energy needs and activity. Overall, the carcinogenic process that defines each malignant tumor determines the metabolic profile of the cells. For the purpose of examining the metabolic switch, this paper will focus primarily on the Warburg principle with only slight examination of other cancer cell metabolic profiles.
The Typical Cell Metabolism
In a typical cell, the mitochondria works to provide the cell with adequate energy (in the form of ATP) in a well organized system. This system takes the glucose from the body and through glycolysis breaks it down to pyruvate, releasing 2 ATP. The products of glycolysis then enter the mitochondria, and are decarboxylated and attached to coA. Acetyl-coA can then enter the Krebs’s cycle. The Krebs cycle is
The krebs cycle is the second step in aerobic respiration of cells, which takes place in the matrix of the mitochondria of eukaryotic cells. This process is to oxidize pyruvate.
The main function of the mitochondria is to convert fuel into a form of energy the cell can use. Specifically, the mitochondria is where pyruvate --derived from glucose-- is converted into ATP (Adenosine triphosphate) through cellular respiration. Cellular respiration involves four stages: glycolysis, the grooming phase, the citric acid cycle, and oxidative phosphorylation. The final two stages listed occur in the mitochondria.
In contrast, there are four metabolic stages happened in cellular respiration, which are the glycolysis, the citric acid cycle, and the oxidative phosphorylation. Glycolysis occurs in the cytoplasm, in which catabolism is begun by breaking down glucose into two molecules of pyruvate. Two molecules of ATP are produced too. Some of they either enter the citric acid cycle (Krebs cycle) or the electron transport chain, or go into lactic acid cycle if there is not enough oxygen, which produces lactic acid. The citric acid cycle occurs in the mitochondrial matrix, which completes the breakdown of glucose by oxidizing a derivative of pyruvate into carbon dioxide. The citric acid cycle produced some more ATPs and other molecules called NADPH and FADPH. After this, electrons are passed to the electron transport chain through
There are two types of cellular respiration, aerobic and anaerobic. Aerobic respiration occurs when there is oxygen present and in the mitochondria (in eukaryotic cells) and the cytoplasm (in prokaryotic cells). Aerobic respiration requires oxygen; it proceeds through the Krebs cycle. The Krebs cycle is a cycle of producing carbon dioxide and water as waste products, and converting ADP to thirty-four ATPs. Anaerobic respiration is known as a process called fermentation. It occurs in the cytoplasm and molecules do not enter the mitochondria for further breakdown. This process helps to produce alcohol in yeast and plants, and lactate in animals. Only two ATPs are produced through this process. In yeast fermentation is used to make beer, wine, and whiskey.
Introduction: Cellular respiration and fermentation are used in cells to generate ATP. All cells in a living organism require energy or ATP to perform cellular tasks (Urry, Lisa A., et al. , pg. 162). Since energy can not be created (The first law of thermodynamics) just transformed, the cell must get its energy from an outside source (Urry, Lisa A., et al. , pg.162). “Totality of an organism’s chemical reactions is called metabolism” (Urry, Lisa A., et al., pg. 142). Cells get this energy through metabolic pathways, or metabolism. As it says in Campbell biology, “Metabolic pathways that release stored energy by breaking down complex molecules are called catabolic pathways” (Urry, Lisa A., et al. pg.
Aerobic respiration happens only when oxygen is presented in the cell. Aerobic respiration starts with pyruvate crossing into the mitochondria. When it passes through, a Coenzyme A will attach to it producing Acetyl CoA, CO2, and NADH. Acetyl CoA will enter into the Krebs cycle. In the Krebs cycle Acetyl CoA will bound with Oxaloacetic Acid (OAA), a four carbon molecule, producing the six carbon molecule, Citric Acid. Citric Acid will reorganize into Isocitrate. This will lose a CO2 and make a NADH turning itself into alpha ketoglutarate, a five carbon molecule. Alpha ketoglutarate will turn into an unstable four carbon molecule, which attaches to CoA making succinyl CoA. During that process a CO2 and NADH is made. An ATP is made when CoA leaves and creates Succinate. This molecule is turned into Fumarate, creating two FADH2 in the process. Then Fumarate is turned into Malate then into OAA making two NADH. Only two ATP is produced in Krebs cycle but the resulting NADHs and FADH2s are passed through an electron transport chain and ATP synthase. When the molecules passes through that cycle a total of 28 ATP molecules are produced. In all aerobic respiration produces 32 ATP and waste products of H2O and
You would expect for the normal lung cells to not have to divide as often because those cells are not exposed to many things through out the day. The normal stomach cells on the other hand would be expected to divide more because there is a lot of acidity in the stomach and therefore those cells are exposed to a lot of things on a daily basis. As for the ovaries you would expect that there would be a little more cell division because that is where new life is formed and all of the things that come along with that which means that there should be more division going on.
The citric acid cycle, also called the Krebs cycle or the tricarboxylic acid, TCA, cycle, a series of chemical reactions that generates energy from the oxidation of acetate into chemical energy and carbon dioxide in the form of ATP. It also provides NADH, which is a reducing agent that is very common in biochemical reactions. This cycle is constantly supplied with new carbon. This comes in from acetyl-CoA, which starts the entire process of the citric acid cycle. The first step of the citric acid cycle is the aldol condensation of oxaloacetate and acetyl-CoA and water with the enzyme citrate synthase in order to form citrate and CoA-SH. The next step is the dehydration of citrate with the enzyme aconitase in order to form cis-aconitate and water. Then comes the hydration of cis-Aconitate and water with the enzyme aconitase in order to form isocitrate. The next is the oxidation of isocitrate and NAD+ with the enzyme isocitrate dehydrogenase in order to form oxalosuccinate and NADH and H+. Then, there is the decarboxylation of oxalosuccinate with the enzyme isocitrate dehydrogenase in order to form alpha-ketoglutarate and carbon dioxide. Next, there is the oxidative decarboxylation of alpha-ketoglutarate and NAD+ and CoA-SH with the enzyme alpha-ketoglutarate dehydrogenase in order to form succinyl-CoA and NADH and H+ and carbon dioxide. The next step is the substrate-level phosphorylation of succinyl-CoA and GDP and Pi with the enzyme succinyl-CoA synthetase in order to form succinate and CoA-SH and GTP. Then, there is the oxidation of succinate and ubiquinone with the enzyme succinate dehydrogenase in order to form fumarate and ubiquinol. Next, is the hydration of fumarate and water with the enzyme fumarase in order to form L-malate. The final step is the oxidation of L-malate and NAD+ with the enzyme malate dehydrogenase in order to form oxaloacetate and NADH and H+. Two cycles are required for every single glucose molecule because two acetyl Co-A molecules
The acetyl group from pyruvate is oxidised in a series of nine reactions; the citric acid cycle. Also known as the Krebs cycle, it is the second stage of cellular respiration. Cellular respiration is a 3 stage process where organic fuel molecules are broken down, in the presence of oxygen, to harvest energy. These reactions occur in the mitochondrial matrix.
Cellular respiration involves glycolysis, the Krebs cycle, and the electron transport chain. Glycolysis is a
Glycolysis is followed by the Krebs cycle, however, this stage does require oxygen and takes place in the mitochondria. During the Krebs cycle, pyuvic acid is broken down into carbon dioxide in a series of energy-extracting reactions. This begins when pyruvic acid produced by glycolysis enters the mitochondria. As the cycle continues, citric acid is broken down into a 4-carbon molecule and more carbon dioxide is released. Then, high-energy electrons are passed to electron carriers and taken to the electron transport chain. All this produces 2 ATP, 6 NADH, 2 FADH, and 4 CO2 molecules.
acetyl CoA. The Krebs cycle is the final stage of respiration. In the mitochondria, a series of redox reactions take place to produce reduced coenzymes and ATP. Oxaloacetate combine acetyl CoA to produce citrate, releasing CoA as a by-product. Decarboxylation occurs again and carbon dioxide is released as citrate is converted into a 5-carbon compound and NAD is reduced. As oxaloacetate is regenerated, more carbon dioxide molecules are released, NAD and FAD are reduced and ADP is joined by an inorganic phosphate to produce ATP (another source of direct and immediate energy).
The Krebs cycle is a series of reactions which occur in the mitochondria and results in the formation of ATP and other molecules which undergo farther reactions to form more ATP. Cellular respiration can be divided into four sequences. The first sequence is glycolysis, its breaks down one molecule glucose into two molecules pyruyate. Transition takes place in the matrix of the mitochondria and it’s referred to the beginning of aerobic respiration. The process takes place if there is enough amounts of oxygen in the mitochondria. However if there is insufficient oxygen in the mitochondria it could result into fermentation. Transition Reactions take place in the pyruvate molecule. In transition reactions two hydrogen electrons and one carbon
Cancer is one of the leading causes of death worldwide as it can develop in almost any organ or tissue. Significant advances in understanding the cellular basis of cancer and the underlying biological mechanisms of tumour has been vastly improved in the recent years (Jiang et al. 1994). Cancer is a genetic disease which requires a series of mutation during mitosis to develop, its characteristics can be associated with their ability to grow and divide abnormal cells uncontrollable while in the mean time invade and cause nearby blood vessels to serve its need. Even though many people are affected by cancer today, the abilities which cancer cells have make it hard to find a single effective treatment for cancer. The focus of research now lies
Cancer is a disease that can change the life of a person no matter their age or nationality. Cancer can range from being life threatening to a low risk of death. Cancer cells are cells that do not follow the regular cell growth and division pattern. They go through cell division and produce rapidly. Cancer cells differ from regulating cells in the body because normal cells eventually die. Cancer cells, on the other hand, do not die when they should causing it to be very hard to cure cancer in your body.