English Worksheet about Grammar, Essays (high school) of English

Download English Worksheet about Grammar and more Essays (high school) English in PDF only on Docsity! Chapter 8, Lesson 3: Cellular Respiration Made by: Mohammad Hajjiri 11AB Why is breathing vital to life? How is the air you breath in different from the air you breath out? By breathing, we get in O2, whereas, it is needed in the process of Cellular respiration; to get the energy needed in all cellular activities. With that, the air we breathe in has high concentration of O2 and the air we breathe out has high concentration of CO2. The respiratory system is the body system which is responsible for the gas exchange (mechanical respiration) which is the take in of O2 and gets rid of the CO2. When the air is inhaled, it enters the body through the upper respiratory tract until it reaches to the trachea and finally into the lungs. In each lung, there are air sacs known as the alveoli (alveolus in singular). In alveoli, the blood reaches carrying CO2 from all the body cells as a product of cellular respiration. The air reaches the alveoli carrying O2. With that, the gas exchange takes place in the alveoli in which the air takes CO2 from the blood and the blood takes O2 from the air. (Simple Diffusion Process). (Oxygenated blood has a higher concentration of O2) The oxygenated blood then is transported to the heart to be pumped all over the body. O2 is a very important reactant as it is for cellular respiration to produce ATP. Cellular Respiration is a catabolic pathway in which glucose is broken down in the presence of O2 to produce ATP energy needed to perform all cellular activities. (Glucose is oxidized maximally to harvest the maximum amount of ATP in Cellular Respiration) There are two types of respiration: 1. Aerobic Respiration: (Cellular Respiration): Aerobic means it requires oxygen to occur. This respiration happens in eukaryotes; they have mitochondria and can take in O2 to complete the aerobic respiration (Cellular Respiration) in which it harvests 36 ATP by each glucose molecule. 2. Anaerobic Respiration: It is a respiration process in which glucose is broken down and ATP is produced but in the absence of O2. This process is known as fermentation as it takes place completely in the cytosol. It harvests few numbers of ATP. Bacteria and yeasts are examples of organisms that can perform this type of respiration. Fermentation has two types: - Lactic Acid Fermentation: It produces lactic acid as a byproduct. - Alcoholic Fermentation: It produces CO2 and ethanol as byproduct. Yeasts use alcoholic fermentation along with many bacteria that use lactic acid fermentation like the bacteria that is added to the dairy products to add the sour flavor. Lactic Acid Fermentation takes place in humans as well. Sometimes, muscle cells use it to get energy in case there was any sort of insufficient amount of O2 when we do intensive exercises. Muscle fibers include the enzymes needed to do both Cellular Respiration and fermentation. In case of any sort of insufficient O2, muscles use Lactic Acid Fermentation temporarily until the body restores the O2 level in blood by deep breathing. Lactic Acid Fermentation causes fatigue in the muscles, which is the feeling of tiredness or lack of energy. It is due to the Lactic Acid which is a byproduct of the fermentation. Lactic Acid will be, then, detoxified in the liver by O2. Red Blood Cells (RBCs) are another example of human cells that always use Lactic Acid Fermentation. RBCs lack mitochondria because the space inside it is needed for the protein hemoglobin to carry O2 to all cells. Cellular Respiration In this lesson, we will be focusing on the aerobic respiration known as the Cellular Respiration. Both aerobic and anaerobic respiration start with the process named by Glycolysis (which is the breakdown of glucose) which takes place in the cytosol and it doesn’t require O2. With that, the glycolysis is an anaerobic step of respiration. Cytosol – The fluid that fills the cell. Cytoplasm – The fluid and the organelles. Cellular Respiration takes place in the mitochondria. Simply, it just begins in the cytosol by glycolysis. The chemical equation of the cellular respiration is: C6H12O6 + 6O2 ----> 6CO2 + 6H2O + energy (36 ATP + Heat) The equation of cellular respiration is related to the photosynthesis. Due to the Pyruvate Oxidation, the Acetyl CoA is produced whereas it is the molecule that can now bind to the initiative enzyme in the Krebs Cycle or Citric Acid Cycle. CoA is added to the acetyl to guide it to bind to this enzyme and start the cycle. The net products of pyruvate oxidation are 2CO2, 2NADH, and 2 Acetyl CoA, whereas, each pyruvate gives 1 CO2, 1 NADH, and 1 Acetyl CoA. Since we have 2 pyruvates produced from the glycolysis, due to that, 2CO2, 2NADH, and 2 Acetyl CoA are produced. CO2 is a byproduct whereas it is collected and carried by the blood in the blood vessels (veins) from all the body cells. With that, it is sent to the heart to be pumped to the lungs. In the lungs, gas exchange takes place in the alveoli to take in O2 and get rid of CO2. NADH is an energy carrying molecule, energy transfer molecule, or an electron carrying molecule. It goes towards the ETC embedded in the mitochondrial inner membrane to phosphorylate ADP to make ATP. Lastly, the Acetyl CoA enters the citric acid cycle. Stage 3: Citric Acid Cycle (Krebs Cycle) It takes place in the mitochondrial matrix whereas it comes after the pyruvate is oxidized in the matrix. It is, also, a cycle whereas the molecule we start with should also be end with to repeat the cycle. For each Citric Acid Cycle, 2 turns are there; we have 2 Acetyl CoA produced from the pyruvate oxidation. Moreover, the main purpose of the Krebs Cycle is to oxidize acetyl more to harvest more electron carriers to produce more ATP later. With that, we have more of redox reactions in the Krebs Cycle. What exactly happens in the Citric Acid Cycle: 1. Acetyl CoA combines to another 4-carbon-molecule known as Oxaloacetate; to produce a 6- carbon-molecule called Citrate or Citric Acid. CoA is released whereas this reaction is catalyzed by a certain enzyme called citrate synthase. 2. Citric Acid will remove CO2 to reduce 1 NAD+ into NADH. With that, the citric acid becomes with 5-carbon-atoms whereas, due to that, we will have a 5-carbon-molecule. NAD+ + 2e- + H+ ----> NADH. 3. 5-carbon-molecule will remove CO2 again and will be oxidized to reduce another NAD+ into NADH whereas the result will be 4-carbon-molecule. 4. 4-carbon-molecule will pick up Pi which is a free inorganic phosphate group to add it into the GDP in order to make GTP or ADP in order to make ATP. GDP – Guanosine Diphosphate GTP – Guanosine Triphosphate. It is equivalent to ADP and ATP. Example: GTP is produced in the liver cells while ATP is produced in the muscle cells after taking Pi and adding it to produce ATP on GTP. The 4-carbon molecule is converted into another 4-carbon-molecule. 5. The 4-carbon will be oxidized to reduce FAD into FADH2 whereas the 4-carbon-molecule is converted into another 4-carbon-molecule. FADH2 is another electron carrier molecule similar to NADH. FAD + 2e- + 2H+ ----> FADH2. 6. The new 4-carbon-molecule will be hydrated (take in H2O from the matrix) and will be converted into another 4-carbon molecule. 7. The new 4-carbon-molecule will be oxidized again to reduce NAD+ into NADH and regenerate the oxaloacetate which is a 4-carbon-moelcule. Each turn of the Citric Acid Cycle will produce 3NADH, 1FADH2, 1ATP or GTP, and 2CO2. Since there are 2-Acetyl CoA, the net product of the Citric Acid Cycle (which is two turns) are 6NADH, 2FADH2, 4CO2, and 2ATP, or GTP. After the Krebs Cycle, the glucose is completely oxidized to release the maximum amount of energy to produce the highest amount of ATP. At the end of all glycolysis, the pyruvate oxidation and Krebs Cycle. There are the following products: - 4 ATP: 2 Glycolysis and 2 Citric Acid Cycle. - 10 NADH: 2 Glycolysis, 2 Pyruvate Oxidation and 6 Citric Acid Cycle. - 2FADH2: From the Citric Acid Cycle. - 6CO2: 2 from the Pyruvate Oxidation and 4 from the Citric Acid Cycle. All CO2 are exchanged with O2 in the lungs (Inhalation and Exhalation). 4ATP are used in the cell for any cellular processes. With that, there are 12 Electron Carriers, whereas, there are 10NADH and 2FADH2 with entering the ETC. Stage 4: Oxidative Phosphorylation ETC – Electron Transport Chain. All the harvested electron carriers will be oxidized now to lose their energized electrons. All the electrons will be transported through the Electron Transport Chain (which is made up of different proteins embedded in the mitochondrial inner membrane). How many electrons will be transported from oxidizing all these 12 electron carriers, whereas, 10 of them are NADH and 2 of them are FADH2? There are 24 electrons (2e- from each electron carrier). All of these electrons are energized while they are transported through the ETC by consecutive Redox Reactions. After, the energy will be transferred to pump H+ from the mitochondrial matrix to the intermembrane space against the concentration which is from the low concentration area to the high concentration area. This will increase the electrochemical gradient for protons (H+), with that, the protons will diffuse again with concentration from the intermembrane space into the matrix through the ATP synthase which will phosphorylate ADP into ATP. This process in chemiosmosis is similar to the one in the photosynthesis. How many ATP molecule are produced by ETC (Oxidative Phosphorylation)?