**Text Transcription:**Metabolizing a fatty acid via the β-oxidation pathway will generate acetyl CoA, NADH and FADH₂.Based on your biochemical knowledge, the major metabolic intermediate will enter cellular respiration in [Select], and the reduced coenzymes will enter cellular respiration in [Select].Could a mature red blood cell perform the β-oxidation pathway?[Dropdown Option Selected: Yes, in their cytoplasm.]**Explanation:**The text is part of an educational prompt about biochemical pathways, specifically β-oxidation. It references the production of acetyl CoA, NADH, and FADH₂, which are important molecules in the process of cellular respiration. The text invites users to select answers related to where these intermediates and coenzymes enter cellular respiration. Additionally, there’s a question about whether mature red blood cells can perform the β-oxidation pathway, with the provided answer being "Yes, in their cytoplasm."There is no graph or diagram present in the image.

Fatty acids are carboxylic acids with a hydrocarbon chain ranging from 4 carbons to 36 carbons. Saturated fatty acids undergo beta-oxidation to produce acetyl CoA and electron carriers such as NADH and FADH2 that are used up during cellular respiration to generate ATP.The enzyme fatty acyl-CoA synthase (FACS) adds a CoA group to the fatty acid chain to form acyl-CoA.1. The enzyme acyl-CoA dehydrogenase oxidizes the acyl-CoA. There is a formation of a trans-configuration double bond between 2C and 3C. The end product is called trans-Δ2-enoyl-CoA. FAD is reduced to FADH2 in this step.2. Enoyl CoA hydratase adds a hydroxyl group to the 2C of trans-Δ2-enoyl-CoA to form L-β-hydroxyacyl CoA3. The 3-hydroxyacyl-CoA dehydrogenase catalyzes the oxidation of L-β-hydroxyacyl CoA to β-ketoacyl CoA and reduces NAD+ to NADH.4. β-ketoacyl CoA is cleaved by β-ketothiolase between 2C and 3C to produce acetyl-CoA and new acyl CoA This acetyl CoA is made up of carbons 1C and 2CThe new acyl-CoA chain which is now two carbons shorter will enter the second beta-oxidation cycle and with each cycle, the fatty acyl CoA will be 2 carbons shorter.Cellular respiration is a collection of three metabolic pathways that generate ATP through the oxidation of glucose. The three pathways are Glycolysis, Tricarboxylic Acid Cycle and Electron transport chain(ETC). Glycolysis:In glycolysis, a 6-carbon molecule of glucose-6-phosphate is broken down into 3-carbon pyruvate. It consists of 10 enzymatically catalysed reactions. In phase 1 of glycolysis (first 5 reactions) 2 molecules of glyceraldehyde 3-phosphate are produced from a single glucose molecule and 2 ATP are consumed. In phase 2 (last five reactions) of glycolysis, glyceraldehyde 3-phosphate is converted to pyruvate and 2 ATP + 1 NADH is produced as byproduct.Pyruvate dehydrogenase complex:Pyruvate is oxidised to acetyl CoA by the enzyme pyruvate dehydrogenase complex and 1 NAD+ is reduced to NADH per pyruvate that is oxidised by PDHC.Acetyl CoA delivers the acetyl group to the TCA cycle.TCA cycle:The TCA cycle uses acetate and water to reduce NAD+ to NADH and FAD+ to FADH2. For every Acetyl CoA, we get 3 NADH, 1 FADH2 and 1 GTP from TCA. NADH and FADH2 enter the electron transport chain.The electron transport chain:ETC consists of four protein complexes called Complex I, II, III and IV that transport electrons from electron donors NADH/FADH2 to electron acceptor: Oxygen to regenerate NAD+ and FAD for the TCA cycleIn the ETC:Each NADH pumps 10 H+ into IMS(4 from Complex I, 4 from Complex III, 2 from Complex IV)Each FADH2 pumps 6 H+ into IMS(4 from Complex III, 2 from Complex IV) As per the chemiosmotic model, the proton motive force drives the ATP synthesis. ATP synthase has two domains F1 and F0. F0 has a pore through which protons 'leak'. By the rotational catalysis mechanism, three active sites of F1 take turns catalysing ATP synthesis from ADP and Pi.To produce 1 ATP, ATP synthase pumps 4H+ from intermembrane space to the matrix. Therefore: Each NADH yields 2.5 ATP moleculesEach FADH2 yields 1.5 ATP moleculesTo summarise, Beta oxidation produces Acetyl CoA, NADH and FADH2. Acetyl CoA is the major metabolic intermediate of the beta oxidation pathway and it enters the citric acid cycle to generate more NADH and FADH2. NADH and FADH2 are the reduced coenzymes that will enter the electron transport chain. Note that the mature RBC's biological role is to transport oxygen. It lacks a mitochondria because mitochondria are a site of oxidative phosphorylation, a process that consumes oxygen. mMature RBC's lack of mitochondria prevents it from consuming the oxygen it is meant to transport. No ETC means no regeneration of NAD/FAD which are important cosubstrates of beta oxidation. Since NAD/FAD cannot be regenerated from NADH/FADH2 in mature RBCs at the rate and amount necessary for beta oxidation, beta oxidation does not occur in mature RBCs.