Stage 1-3 Derivatives

LESSON 4. Cellular Respiration • Define cellular respiration • Identify the stages of clan respiration You have just learned how the energy from the sun is captured, processed, and stored in the form of glucose. Cellular respiration, another important life process, is the means by which cells release the stored energy in glucose to make adenosine triphosphate (ATP). The primary goal of this life process is to convert stored energy into usable form, such as ATP, for the cells to carry out their functions. Cellular respiration involves several chemical reactions. The reactions can be summed up in the following equation: C6 H12 O6 + 602 ----- 6 CO₂ +6H₂O + ATP Glucose oxygen carbon dioxide water energy Aerobic respiration reactions, or cellular respiration that takes place in the presence of oxygen, can be grouped into three stages glycolysis, Krebs cycle, and electron transport chain (ETC). Stage 1: Glycolysis Glycolysis is the process that breaks down one molecule of 6-C glucose into 3-C pyruvates or pyruvic acids. It also releases four molecules of ATP. This process occurs in the cytoplasm of the cell. The following is the step-by-step process of glycolysis. Take note that several enzymes are involved in this process. 1. The first step of glycolysis requires energy. It can only proceed when the two ATP molecules donate energy to the glucose by transferring a phosphate group with the help of an enzyme, producing glucose 6-phosphate 2. Then, a specific enzyme promotes the rearrangement of the atoms, producing the fructose 6-phosphate. 3. The action of the enzyme in step 2 promotes the transfer of a phosphate group from another ATP molecule, forming fructose 1,6-bisphosphate. 4. The resulting fructose 1,6-bisphosphate molecules, with the help of another enzyme, splits into two molecules, each with three carbon backbones. These two sugars are dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. 5. Another important enzyme then rapidly interconverts the molecules of dihydro-xyacetone phosphate and glyceraldehyde 3-phosphate. This produces two molecules of glyceraldehyde 3-phosphate or 3-phosphoglyceraldehyde (PGAL) 6. The succeeding step involves another enzyme-mediated action. The hydrogen (H) from PGAL is transferred to the oxidizing agent, nicotinamide adenine dinucleotide (NAD), which forms NADH. A phosphate (P) is also added from the cytosol of the cell to oxidize the two molecules of PGAL, forming two 1.3-bisphosphoglycerate. 7. A phosphate (P) from 1,3-biphosphoglycerate is transferred to ADP to form ATP. This happens for each of the two 1,3-bisphosphoglycerate. resulting to a yield of two ATP and two 3-phosphoglycerate molecules. 8. A phosphate is transferred from 3-phosphoglycerate molecules from the third carbon to the second carbon, forming 2-phosphoglycerate molecules A hydrogen atom and a hydroxyl ((OH) group is released, which then combines to form water (H2O). The removal of H2O from 2-phosphoglycerate results in the formation of 2- phosphoglycerate molecules. 9. A hydrogen atom and a hydroxyl ((OH) group is released, which then combines to form water (H2O). The removal of H2O from 2-phosphoglycerate results in the formation of two phosphoenolpyruvic acid (PEP) 10. Phosphate (P) from PEP is transferred to ADP (and forms ATP) and the final product, pyruvic acid. This reaction yields two molecules of pyruvic acid and two ATP molecules In summary, a single glucose molecule that undergoes the process of glycolysis produces two molecules of pyruvic acid, four molecules of ATP, two molecules of NADEL and two molecules of H.O. However, only two molecules of ATP are counted as net products since two molecules of ATP are spent throughout the process. Stage II: Krebs Cycle The Krebs cycle, named after its proponent Sir Hans Adolf Krebs, is a cyclical series of enzyme-controlled reactions. This stage of cellular respiration occurs in the matrix of the mitochondria. It is sometimes. called the citric acid cycle (CAC) since it produces citric acid. Citric acid contains three carboxyl (COOH) groups; hence, it is also called the tricarboxylic acid cycle (TCA). This requires the pyruvic acids produced during glycolysis. The main function of this cycle is to produce high-energy-yielding molecules, namely, NADH and flavin adenine dinucleotide (FADH) that will later on be used in the electron transport chain reaction. Figure 6-7. Summary of glycolysis and corresponding products in each reaction presented (See Appendix F on page 285 for an enlarged and complete version of the image.) An initial process is needed for the Krebs cycle to begin. As a pyruvate molecule from glycolysis enters the mitochondrion, it undergoes an important preliminary ate to form acetyl-CoA reaction. Coenzyme-A (COA) combines with pyruvate help of an enzymatic complex. This conversion also produces CO, and NADH. The Krebs cycle is summarized as follows. Take note that several enzymes are involved in this process. 1. The Krebs cycle technically begins when the acetyl-CoA combines with oxaloacetic acid (OAA), a 4-C molecule, to produce citric acid, a 6-C molecule. 2. With the aid of an enzyme, the citric acid now goes through a series of reactions that releases energy. Water molecule is removed from the citric acid and is returned in a different location. The-OH group is repositioned, forming the molecule isocitrate. 3. Isocitrate is then oxidized, forming the a-ketoglutarate, a 5-C molecule. The byproducts of this reaction are NADH and CO, 4 The a-ketoglutarate loses its CO, and a coenzyme-A is added in its place. The decarboxylation occurs with the help of NAD, which then becomes NADH. The resulting molecule is called succinyl-CoA. 5. Succinyl-CoA is converted into succinate. Also in this reaction, a molecule of guanosine triphosphate (GTP) is synthesized. The GTP molecule has similar structure and energy properties to that of ATP and is used by cells the same way. The free phosphate group attacks the succinyl-CoA molecule, which detaches the COA. Then, phosphate is attached to GDP to come up with GTP, similar to the process that occur in ATP synthesis (from ADP to ATP). 6. Two hydrogens are removed from succinate, A molecule of flavin adenine dinucleotide (FAD), a coenzyme similar to NAD, is reduced to FADH, as it takes the hydrogens from the succinate. This reaction produces the fumarate. 7. Fumarate is then converted into malate as the addition of a water molecule is catalyzed. The final reaction is the regeneration of oxaloacetate. The resulting byproduct of this regeneration is NADH Recall that two pyruvate molecules were produced during glycolysis, causing the Krebs cycle to turn twice. Each tuts produces three molecules of NADH, single ATH one FADIH, and the by-product CO, which is exhaled. Stage III: Electron Transport Chain The electron transport chain (ETC) is a series of photon pumps on the inner membrane of the mitochondrion. Electron transport is the last stage of the cellular respiration. In this stage, the energy from NADH and FADH, from the Krebs cycle is transferred to ADP to produce ATP. This process is generally known as oxidative phosphorylation. This energy coupling mechanism in the cell was revealed by the work of Peter stored energy in the form of proton (1) gradient to phosphorylate (add phosphate) ADP and produce ATP. The pumping of hydrogen sons across the inner membrane creates higher concentration ions in the inner membrane than on the outside of the membrane. This chemiosmotic gradient causes the ions to flow back across the membrane where the concentration of ions is lower. ATP synthase lined in the matrix serve as a channel protein, helping the ions to move across the membrane. The chemiosmotic gradient powers the phosphorylation of ADP to ATP, which also occurs in the ATP synthase. After passing through the ETC, the oxygen, being the final hydrogen acceptor, combines with two electrons and two protons, forming a water molecule. Water is a by-product of cellular respiration and is excreted. MINI TEST 6-3 1. Which energy-releasing pathway yields the most ATF in each glucose molecule? 2. Briefly describe the two stages of aerobic respiration that follow glycolysis: (a) Krebs cycle (b) Electron transport chain Anaerobic Respiration Most cells carry out arrobic respiration when oxygen is present. Aerobic respiration is an efficient process that yields a lot of ATP. However, many organisms thrive in mud, marshes, animal gut, canned goods, sewage treatment pond, and deep oceans where oxygen is scarce. Organisms that can live without oxygen are called anaerobes. Cellular respiration that proceeds without the presence of oxygen is called anaerobic respiration. In the event that the oxygen supply becomes low, aerobic cells also perform fermentation and lactic acid fermentation anaerobic pathways. There are two common anaerobic pathways in these cells, alcoholic fermentation and lactic acid fermentation. In alcoholic fermentation, ethyl alcohol and carbon dioxide are produced by some cells using the pyruvate from glycolysis. Each pyruvate molecule is rearranged into acetaldehyde and carbon dioxide, which is eventually released. NADII gives up electrons to acetaldehyde to form ethanol Fermentation is widely used in the industry. Yeast, a fungus used in making bread. can undergo anaerobic respiration. Bakers aux sugar, flour, water, and yeast to form the bread dough. The dough rises due to the carbon dioxide and alcohol released by the yeast cells trapped in air bubbles. Beer and wine manufacturers, we yeast to ferment the sugars in wheat and grape juice, forming alcoholic beverages such as beer and wine. In some cells, glycolysis produces two pyruvates, two NADH molecules, and two ATP molecules. Pyruvate itself becomes the final acceptor of the electrons from the NADH that produces the final product: lactate. Oftentimes, this product is called lactic acid. Human skeletal muscles can carry out fermentation when the blood cannot supply the cells with adequate oxygen during strenuous activities. When lactic acid builds up in the muscles, fatigue, burning sensation, and cramps result. Lactic acid will continue to build up until there is adequate supply of oxygen. Lactic acid is then converted back into pyruvate in the liver. Muscles also restore normal functions. Have you ever wondered why milk or cream turns sour after some time? Bacterial cells that undergo fermentation are responsible in producing lactate that turns the milk sour. These bacteria are used in manufacturing yogurt and sour milk products. Fermentation pathways do not breakdown and utilize the glucose completely. ATP is no longer produced beyond the process of glycolysis. Thus, energy produced is just enough for some single-celled organisms, or the energy can only be used by multicellular organisms for a short period.

New product development process, Stage 1: new product strategy development stage 2 idena generation stage 3 idea screening stage 4 business analysis stage 5 product development including prototypes and concept test stage 6 test marketing stage 7 product launch

Stages in the Sale of a Property Stage 1 – Getting to Instruction • Initial contact with the vendor: need to check the following: type of property, contact details of vendor, address of property/Eircode and purpose of the contact - sale or valuation? If a sale, does the vendor need a quick sale? Qualify the lead i.e. is the vendor buying another property? If an investment property, is the tenant in situ? Check if there is a folio number available and confirm the ownership of the property. Schedule the viewing. • Pre-viewing: Set up a file & record all info from initial contact on CRM system. Check the Property Price Register to help get a general idea of property valuation (subject to viewing, helps to display knowledge of area/market and set expectations for the vendor). Nature of property may affect pricing e.g. starter home vs. larger property with vendor seeking to downsize. Consideration for comparables may include similar/same location, size and condition of property, availability and type of parking, layout of property, plot size, orientation of garden, extensions undertaken etc. Nature of market conditions, state of wider economy, cost of capital and availability of credit may also be factors. • Appraisal/viewing: Bring an advertising pack/sales & marketing brochures. Walk through property with client, note nice features/selling points for the brochure, let the client talk about upgrades/specific features of the property. It is very important to listen to the vendor and build rapport. Confirm property details e.g. condition and layout, plot size, orientation of garden. Check for certificates of compliance for any extensions, planning permissions for conversions, right of way if applicable etc. Check if a BER available/provide details for approved assessors. Demonstrate your/the practice’s professional expertise, justify why you should get the instruction, discuss recent local sales and give your potential valuation. Discuss the sales fee, marketing fee and any additional charges e.g. professional photography, drone footage, virtual tours (walkthrough video, Matterport etc.) Ask how the vendor heard about you/your practice and why are they considering you for the sale. Where appropriate offer advice to help vendor increase potential sales price. (If possible, leave with signed Property Services Agreement/Letter of Engagement.) Thank you, send/email market appraisal, any queries/questions do get in touch and let the vendor know that we’ll be in touch in coming days. • Post appraisal – letter sent that pm/next morning with market appraisal; diary note to follow up. Check that market appraisal letter received and check for questions. If did not get sale, find out why not/debrief. If get the sale, email confirmation of instruction. Once PSRA sent and LOE returned signed = stage 2. Other details required – ID, proof of address, proof of ownership/title, solicitor details, BER certificate (refer to assessor if not available). All these should be uploaded to CRM. Stage 2 – Getting to ‘Sale Agreed’ Set up appointment to measure & photograph, note any special features e.g., upgraded kitchen, south-facing garden. Provide ideas for improving sales potential (declutter, painting, tidy garden etc. Check if has vendor potential buyers in mind already e.g., relations, friends, other parties interested. Seek vendor approval for photos/text of brochure. Check for access (tenants in situ/working from home etc) and confirm viewing times. If given a key for viewings – tag it! Check alarm codes & whether a sign is allowed on the property. Bring to market – upload to all websites e.g., daft/my home, in house websites and create window display. Match the property against your internal database of potential purchasers /CRM system. Set up appointments for viewings on CRM or arrange for open viewings. Confirm viewings with vendor & purchaser. Turn on lights, open windows, secure valuables, leave out brochures & business cards, bring viewings sheets to keep record of attendees. Introduce yourself and get attendee details. Let people view the property and address any questions. Point out key features. Record questions to be answered and any feedback from viewers. Ask are they selling property? Let viewers know of offers already received. Lock up/alarm property/close windows. Provide vendor with feedback on viewings - number of viewers / questions raised/overall reaction to property. Offers should be confirmed in writing & upload to on CRM/ offers will be input by bidders onto online bidding platforms ‘Proof of funds’ required for offers in some practices. Successful bidder will be chosen by vendor, who might want quick sale/no chain or prefer the highest bidder. Booking deposit will be sought from successful bidder. The amount varies by practice but must cover fees. Sales Advice Notice/letter should be sent to both solicitors (and may be cc’d to vendor/buyer or notify both that SAN have gone out). Booking deposit receipt should be issued. The BER certificate and report should go to the solicitor. Send requests for docs/info to successful bidder including steps they need to take to progress sale e.g., organise the bank valuation and/or schedule the survey. Once the deposit is paid the property is Sale Agreed, inform other bidders, and update all websites/sales board etc. Stage 3 – Getting to closing Access should be organised for the bank valuation/survey. Stay in touch with both solicitors ‘contract-chasing’ i.e., check when contracts are issued, signed and queries answered. Legal searches undertaken by the solicitors may include checking boundaries, land registry, title, rights of way, compliance certs etc. When contracts are signed 10% purchase price/booking deposit should be sent to the vendor’s solicitor. Once all queries satisfied = drawdown of mortgage/funding, house/life insurance in place. Title deeds will be requested once contract is signed. Decide final closing date. Check that the property taxes have been paid. Check that vendor has vacated the property. When vacant, conduct the final walkthrough and take final readings (MPRNs ). Check with solicitor if the drawn down funds h, and once received the solicitor gives authorisation to the estate agent to release the keys. The agent will do up invoice, send the balance of funds to solicitor and provide gift to purchaser. Finally remove sign, mark as sold on CRM, seek testimonials, upload to social media and close a/c on CRM

ENG 3 #30 On Stage 30.1-30.17 Scrambled

ENG 3 #30 On Stage 30.1-30.17 Multiple GR-EN

Related quizzes

Related quizzes