BTEC Level 3 Applied Science Unit 10 Assignment B - Respiration, Exams of Biology

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BTEC Level 3 Applied Science Unit 10 Assignment B - Respiration Effect of Activity on Respiration in Humans Introduction to Respiration Breathing and respiration are two separate processes. Breathing is the process of moving air in and out of the lungs (inhalation and exhalation). Respiration is the process in all living organisms where energy, ATP, is produced in cells. ATP is adenosine triphosphate, which is a phosphorylated nucleotide with a similar structure to DNA and RNA. ATP is unable to leave the cell it was produced in. It occurs in the mitochondria, which are found in all animal cells. The mitochondria have two membranes, which are important as they allow the aerobic respiration reactions to be separated from the rest of the cell. There are also enzymes which are important for the Link Reaction and Krebs Cycle stages of respiration. These enzymes are housed in the matrix of the mitochondria. A large surface area is provided by the cristae of the mitochondria, which is important as it allows for many Electron Transport Chains. Why is respiration important? Respiration is required in cells to produce energy, which allows for other processes within the body to function properly. Examples of bodily functions which require the energy produced in respiration are active transport, muscle contraction, synthesising proteins and enzymes from larger molecules, cellulose from glucose, starch from glucose, and amino acids from glucose and nitrates. Aerobic Respiration — Aerobic respiration is respiration using oxygen. This occurs in animal cells and plant cells, as well as a limited number of micrabes. Aerobic respiration is more efficient than anaerobic respiration and releases a higher amount of energy. Energy released from the glucose and oxygen is around 32 ATP molecules. Aerobic respiration takes place in the mitochondria. Equation: Glucose + Oxygen 2 Carbon Dioxide + Water Anaerobic Respiration — Respiration that takes place in animal, plants, and some microbial cells in condition of low oxygen or absence of oxygen. Some examples of where anaerobic respiration occur include plant roots in waterlogged soil, bacteria in puncture wounds and human cells during vigorous exercise. Anaerobic respiration in microbes can be used to make useful products. Bacteria are used to break down waste to make biogas. Yeast is used to make carbon dioxide in dough to make bread rise. Yeast can also be used to ferment sugars to make alcohol in beer and winemaking. Less energy is released (2 ATP molecules) than that of aerobic respiration. Equation: Glucose Bl Lactic Acid (some energy released) Or Glucose @ Ethanol + Carbon Dioxide (some energy released) In aerobic respiration, the heart is unable to get enough oxygen to the muscles during exercise, so the body produces energy via anaerobic respiration in an attempt to combat the lack of oxygen that the body is receiving. It releases energy from glucose, but the amount is lower. It happens when there is not enough oxygen for aerobic respiration. Anaerobic respiration is a short-term fix as too much lactic acid produces after anaerobic respiration can lead to a stitch or taste in mouth. Lactate builds up in the cells, causing fatigue, hence why you become tired after lots of physical activity. It is a waste product. Our cells produce lactate to provide energy during exercise when oxygen is not readily available to do so via aerobic respiration. Lactate fermentation is a way of producing ATP without the need for oxygen as lactate allows for glucose to be broken down. It temporarily converts pyruvate into lactate, which allows glucose breakdown. Anaerobic respiration produces an oxygen debt. This is the amount of oxygen needed to oxidise lactic acid to carbon dioxide and water. This is because glucose is not broken down completely to form carbon dioxide and water. Some of it is braken down to form lactic acid. The lactic acid is metabolised by the liver, converting some it back to pyruvate which then undergoes aerobic respiration, which requires O02. The existence of an oxygen debt explains why we continue to breathe deeply and quickly for a while after exercise. Stages of Respi -P2 Glycolysis Glycolysis is the first stage of respiration and occurs in both aerobic respiration and anaerobic respiration. The purpose of this stage is to convert large molecules of glucose into small molecules called pyruvate. This can then be transported to the mitochondria, which is the double-membraned organelle found in human cells. It is important to start off the glycolysis stage with 2 ATP, as it will allow for more ATP to be produced later on in glycolysis. Phosphorylated Glucose is extremely unstable, as it separates into two molecules of Triose Phosphate almost instantly. Pyruvic Acid is formed when triose phosphate is oxidised (also known as Pyruvate). The coenzyme NAD is responsible for this, and NADH (reduced NAD) is generated as a result of the process. This is known as a redox reaction, in which one molecule is reduced while the other is oxidised. 2 ATP, 2 x NADH, and 2 x Pyruvate are the results of glycolysis. There is now a total of four ATP. This ATP is an example of substrate-level phosphorylation. Aerobic and anaerobic respiration differ after glycolysis. This is the only stage that is shared. Energy is required for glycolysis to take place. Without glycolysis, the other stages of respiration would not be able to take place. The energy that glycolysis uses to take place essentially ‘kick-starts’ the respiration process. It requires a small amount ATP, which allows more ATP to be produced by the end of this phase. Where glycolysis requires energy to take place, the subsequent phases complete the transformation of Pyruvate to produce ATP as well as NADH. The energy produced here is for the cell to use. proceeds through a sequence of oxidation processes in which three NAD molecules are reduced to three NADH molecules. FAD, which is degraded to FADH2, is a second coenzyme involved. Phosphorylation of the substrate results in the formation of one molecule of ATP. These reactions produce a four-carbon product, which can subsequently be joined to another molecule of Acetyl CoA to complete the cycle. The Krebs’ Cycle produces 2 x 4C compound, 6 x NADH, 2 x FADH2, 2 x ATP, 2 x CoA, and 4 x CO2 from one molecule of glucose. The generated Coenzyme A returns to Link Reaction to react with additional Pyruvate to form Acetyl CoA. NAD and FAD, the two coenzymes that carry material to the electron transport chain, are present once more. Later on, the distinction between the two coenzymes will become evident. At this point in respiration, not much ATP has been produced, despite having produced large amounts of reduced coenzymes NADH and FADHz2, which are required to produce ATP. The Krebs Cycle only results in 2 ATP molecules being produced, which is the same number as in glycolysis. Despite its low amount of ATP molecules produced, the Krebs Cycle is important as it is the stage where reducing agents are produced for the Electron Transport Chain, which is arguably the most important stage of respiration as it is where most of the energy is produced. Electron Transport Chain (Oxidative Phosphorylation) The Electron Transport Chain is a collection of proteins which are lodged into the phospholipid bilayer of the internal membrane of the mitochondria. Inter-membranal Space fifa wu due Complex | Complex I (NADH (FADH; Complex Complex IV DeHydrogenase) © DeHydrogenase) ATP Synthase (stalked particle) Mitochondrial Matrix Electrons pass through the protein channels. The proteins release a small amount of energy. The energy released here is used to carry protons from the matrix region of the mitochondria to the inner membrane of the mitochondria. At the very end of the Electron Transport Chain, an enzyme called ATP synthase is present. The higher the number of protons that are pumped into the inner membrane of the mitochondria, the larger the concentration gradient becomes. This leads to more protons being pushed through the ATP synthase. The ATP synthase uses the produced energy to synthesise ATP from ADP and Inorganic Phosphate as the protons rush through. The Electron Transport Chain is categorised into complexes and is sorted based on the proteins. Complex | is where the protein, NADH Dehydrogenase, arrives from earlier stages of respiration, such as the Link Chain and Krebs Cycle. Here, a hydrogen molecule is donated by the NADH. The donated hydrogen molecule divides into two electrons and two protons. The electrons briefly become attached to Complex |, which is what causes it to become reduced. The NADH then transforms back into its oxidised form (as it has gained electrons) which is NAD. NAD can then continue transporting. The electrons then move straight to Complex Ill, and whilst they move, a small amount of energy is released, which is used by Complex | to pump the two protons gained by the hydrogen molecule through the Complex | and into the inner space of the membrane. Complex II consists of the coenzyme FADH2, which is only able to bind to Complex II. With Complex II being the only Complex it can bind to, FADH2 cannot use the ‘proton pumping power’ from Complex |. This results in a lower level of ATP being produced in comparison to that produced by NADH. FADH2 loses two electrons (oxidises), which move from Complex II to Complex III. The protons do not move, as they are needed in the matrix for pumping later on. When the complex receives electrons again, it reduces. It oxidises when it passes them on again. Complex III receives electrons from Complex | or Complex II. This leads to the reduction of Complex Ill. The electrons then move to Complex IV, oxidising Complex Ill again. The transfer of electrons, once again, results in a low level of energy being released, which allows the two protons to pump through to the inner membrane space. Complex IV receives electrons from Complex III, which reduces it, as it has gained electrons. At this complex, the electrons are passed through to the matrix region of the complex, where they come together with protons and oxygen (which have passed through the ATP Synthase prior to this stage) to form water. Once oxygen accepts these electrons, Complex IV is oxidised once again, as it has now lost these electrons. The movement of electrons, again, releases a small amount of energy which is used to pump the protons gained through to the inter-membranal space so that they can pass through the final protein, ATP Synthase. ATP Synthase is the final protein in the Electron Transport Chain that receives the large number of proteins which have congested in the inner membrane space. This means that a large proton gradient has been established, which helps with the movement back into the matrix region of the mitochondria. Protons are only able to take this route, through the ATP Synthase enzyme. The energy released by the proteins passing through is used to form ATP. The energy released at this stage is extremely important, as it is where most of the ATP (34 ATP molecules) is produced for respiration. Without the energy produced at this stage of respiration, the body would suffer from a lack of ATP (as the amounts produced from the previous stages would not suffice) and bodily functions would not be able to take place efficiently, or as much as they should. into the bromothymol blue solution and formed carbonic acid quicker than it did at resting, showing that it was produced and released much quicker than at resting. This shows that more oxygen has been taken in as required by respiration, because the rate of respiration sped up during exercise. Evaluation Using Secondary Data | compared my results to secondary data collected by a peer who followed the same experimental method as | did. Their results show the same trend occurring as with my results, which is evidence that the experiment was accurate. The accuracy is increased by the fact that the same type of exercise was carried out, as well as the same amount. However, | would need to compare my data with more secondary data to gain a true idea of the accuracy of the experiment. REST REST — No Exercise ) 4 20 Star Jumps 7 2 20 Star Jumps ? 3 20 Star Jumps 6 Though there are no anomalies, and the results are as expected, there are some factors within the investigation which could have affected the results. For example, the speed of the star jumps may have affected the rate at which respiration occurred. Also, the time taken between finishing the exercising and returning to the solution to exhale into it would have differed slightly between each repeat as it was not recorded. The more time left between the exercise and the exhalation process would have allowed the respiration rates to decrease slightly. This may have resulted in data that looked as if more exercise has resulted in less carbon dioxide being produced. This did not happen in this investigation, but for future investigations, this is something that | would keep in mind. Overall, after comparing my data to the data of my peers, it would seem as if the results were accurate, and that the conclusion is made using these results is reliable. Factors Which Affect Respiration — P4, M3, D2 Chemicals in Cigarettes Toxic substances are found in cigarettes. Tobacco smoke Healthy lung Smoker's hang contains about 7,000 compounds, 250 of which are - Ranta nee hazardous. 69 of the 250 hazardous substances have the 7 —e potential to cause cancer. Carbon monoxide, ammonia, No infa Patines of titervanaiion hydrogen cyanide, and tar are all harmful substances. arger than normal size Nicotine, whi h is addictive, is also present in cigarettes. Because it is poisonous, it is utilised in pesticides. Smokers can opt to smoke either self-rolled or traditional cigarettes. Although self-rolled cigarettes may not contain as many chemicals as cigarettes, the chemicals they do contain are nonetheless extremely toxic, and the smoke exhaled from these cigarettes contains enough poisons to be dangerous. Nicotine, carbon monoxide, tar, and tobacco-specific nitrosamines are still present in self-rolled cigarettes. Arsenic, benzene, beryllium (a poisonaus metal), cumene, ethylene oxide, nickel, tobacco-specific nitrosamines, and vinyl chloride are some of the cancercausing compounds found in tobacco smoke. Carcinogens are substances that cause cancer. Carbon monoxide is a highly poisonous and dangerous gas. It is a by-product of incomplete carbon-containing fuel combustion, and so is formed when tobacco is burned incompletely. As the quantities of carbon monoxide in your bodily tissues rise, your heart and lungs are put under strain. The heart will work harder to pump oxygenated blood from your lungs to the rest of your body, which it incorrectly believes is oxygenated. The airways swell as a result, allowing even less air to reach the lungs. Long-term exposure causes lung tissue destruction, which leads to cardiovascular issues and lung illness. Carbon monoxide can impair the body's ability to transport oxygen if breathed. This is why people exposed to extremely high levels of carbon monoxide die, as they have suffered from asphyxiation or lack of oxygen to the brain. Oxygen is essential for respiration, as during the Electron Chain Transport stage of respiration, oxygen is necessary as it is the last electron acceptor. Without oxygen, this process is disrupted. Tar is a sticky material that adheres to lung tissue and narrows and plugs arteries in the body, reducing blood flow. Tar narrows the bronchioles, small tubes, in the lungs which damages the lungs. These bronchioles absorb oxygen. When oxygen is inhaled, it diffuses into the blood, where it is transported around the body and to the body’s cells and tissues. A lack of consistent blood flow, due to the damage of the bronchioles, would lead to inefficient respiration by the cells. The cilia, which are small hairs on the inside of the body, also become damaged, which leaves the lungs more vulnerable to infections, which would lead to various other respiratory conditions. Overall, the effects of chemicals within cigarettes on the respiratory system are serious and can impair the cells’ abilities to respire as they should. This would lead to bodily processes, such as processes that require energy, not working as they should work or as efficiently as they should. Carbon monoxide is not a chemical found within cigarettes themselves, but it a commonly produced by-product that farms when tobacco is burned incompletely. This by-product directly leads to the cells within the body receiving a lack of oxygen as the red blood cells develop an green areas rather than near busy roads or congested, industrial areas where possible is advised, as well as wearing a face mask in these busy, congested areas to filter the pollutants and particles. These are preventative measures which can be taken, as pollutants in the air cannot be avoided altogether. Inhalation of pollutants such as carbon monoxide or sulphur dioxide are more harmful than pollutants such as dust particles or pollen. Dust particles and pollen are larger and are usually captured by the mucus in the nose, throat and lungs and pushed up with the assistance of cilia (tiny hair-like structures) to exit the body in the form of a cough, sneeze, or phlegm. Pollen is released by plants during the spring and summer seasons. Pollen can be uncomfortable when inhaled but can also be removed from the body in the same way that dust is (via mucus and coughing/sneezing). Some people are allergic to pollen, which makes it a lot more harmful to the respiratory system as pollen allergies can result in the swelling of the airways and therefore limited flow of oxygen, however, medication can be taken to prevent this swelling and ensure that breathing and respiration can occur as normal. These pollutants are more of an obstruction, causing temporary obstruction to the airways and temporary difficulty breathing, unlike damaging chemicals. Carbon monoxide and sulphur dioxide, for example, cannot be pushed out of the lungs via a cough (though coughing could be a symptom of the lung damage that these chemicals cause), nor can their effects be reversed with a simple medication. These chemicals cause long-term damage to the respiratory pathways by depriving the red blood cells of oxygen, leading to body cells not receiving the oxygen required to respire properly. Sulphur dioxide narrows the airways, making breathing more difficult and limiting the flow of oxygen into the body. These chemicals, once inhaled, do not have a quick fix and the damage caused by them can be permanent, making chemical pollution more harmful and severe than particle pollution. Disease — asthma Asthma is a condition that causes your airways to narrow and swell, as well as create excess mucus. This can make breathing difficult, resulting in coughing, whistling (wheezing) on exhalation, and shortness of breath. Asthma is a mild annoyance for some people. For others, it can be a severe issue that prevents them from going about their everyday lives and can even lead to a life-threatening asthma attack. It's unclear why some people develop asthma and others do not, but it's most likely due to a combination of environmental and genetic variables. Asthma triggers vary from person to person and can include pollen, dust mites, mould spores, pet dander, or cockroach excrement particles in the air. Asthma can be triggered by respiratory illnesses such as the common cold. Asthma can be triggered by physical exercise, cold air, air pollutants and allergens, and gastroesophageal reflux disease (GERD), a disorder in which stomach acids back up into the throat. The muscle wall of the airway contracts during an asthma attack, and the lining of the airways becomes swollen and irritated. These changes promote airway narrowing, which is exacerbated by an increase in mucus membrane secretions, which can actually clog the narrower airways. These bronchioles absorb oxygen. When oxygen is inhaled, it diffuses into the blood, where it is transported around the body and to the body’s cells and tissues. A lack of consistent blood flow, due to the damage of the bronchioles, would lead to inefficient respiration by the cells. Oxygen is essential for respiration, as during the Electron Chain Transport stage of respiration, oxygen is necessary as it is the last electron acceptor. Without oxygen, this process is disrupted. Without oxygen, ATP cannot be produced and without ATP, processes within the body, such as the breaking down of larger molecules for digestion, cannot occur. Unfortunately, asthma is still being researched, and so it is not known exactly why a person may develop asthma spontaneously or as a reaction to certain triggers. Anybody can develop asthma and it cannot be prevented or cured. However, there are asthma pumps which are used to help relax the muscles which have tightened around the bronchioles. This allows for more efficient flow of oxygen through the airways, meaning more oxygen can be absorbed by the bronchioles, diffused into the blood, and transported to the cells in the body in order for respiration to occur successfully. Preventative inhalers can also be used day-to-day to relieve inflammation of the airways, to prevent the symptoms of asthma occurring. These are the main ‘treatments’ prescribed for asthma sufferers. It is important that asthma sufferers manage their condition accordingly, as inflamed airways result in inconsistent and inefficient respiration of body cells, which can lead to general feelings of fatigue and weakness due to a lack of energy produced by the body cells.