Which of the following is FALSE? OA. Once an NADH molecule is oxidized it can return to glycolysis. B. In aerobic respiration, for every carbon atom in the original substrate one molecule of carbon dioxide is produced. c. Each FADH2 allows the production of 2 ATP molecules in the ETC. OD. Most organisms are unable to synthesize lipids. OE. None of the above is false. Oh. Identify the processes of glucose metabolism represented by the letters in Figure 5-1. OA A-glycolysis, B-Krebs cycle, C – fermentation, D-electron transport chain OB. A-electron transport chain, B – Krebs cycle, C-glycolysis, D- fermentation OC. A-glycolysis, B = Krebs cycle, C = electron transport chain, D – fermentation, ODA-glycolysis, B = fermentation, C – Krebs cycle, D electron transport chain. OE. A- fermentation, B glycolysis, C = Krebs cycle, D electron transport chain QUESTION 5 Which of the following statements concerning cellular metabolism is FALSE? O ATP is used in the formation of macromolecules. The goal of metabolism is to maintain life. Energy obtained from nutrients or light is stored in the bonds of ATP. O Macromolecules are formed by catabolism. O Enzymes are used in both catabolic and anabolic reactions. QUESTION 6 Which of the following statements is TRUE? O A. For every 2 acetyl CoA entering the Krebs cycle, 4 NADH and 2 FADH2 are produced. OB.2 molecules of ATP are produced when pyruvic acid is transformed into acetyl-CoA. OC. Only aerobic organisms carry out glycolysis. OD. In an electron transport chain, oxygen is always the final electron acceptor. O E. none of the above is true
The Correct Answer and Explanation is :
Let’s analyze each statement to determine which one is false:
A. Once an NADH molecule is oxidized, it can return to glycolysis.
n cellular respiration, NADH is produced during glycolysis and the Krebs cycle.nce NADH donates its electrons to the electron transport chain (ETC), it is oxidized back to NAD⁺.his regenerated NAD⁺ is essential for glycolysis to continue, as it acts as an electron acceptor during the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate.herefore, the oxidized NAD⁺ returns to glycolysis to facilitate ongoing ATP production.his statement is true.
B. In aerobic respiration, for every carbon atom in the original substrate, one molecule of carbon dioxide is produced.
erobic respiration involves the complete oxidation of glucose (C₆H₁₂O₆), a six-carbon molecule.uring this process, each carbon atom is released as carbon dioxide (CO₂).pecifically, two CO₂ molecules are produced during the conversion of two pyruvate molecules to acetyl-CoA, and four CO₂ molecules are released during the Krebs cycle.n total, six CO₂ molecules are produced from one glucose molecule, corresponding to its six carbon atoms.his statement is true.
C. Each FADH₂ allows the production of 2 ATP molecules in the ETC.
ADH₂ is a product of the Krebs cycle and donates electrons to the electron transport chain.raditionally, it has been estimated that each FADH₂ molecule contributes to the production of approximately 2 ATP molecules.owever, more recent studies suggest that the yield might be closer to 1.5 ATP per FADH₂ molecule.espite this updated understanding, the statement aligns with traditional estimates and is generally considered true.
D. Most organisms are unable to synthesize lipids.
his statement is false.ost organisms, including humans, have the capability to synthesize lipids.n animals, lipogenesis occurs primarily in the liver and adipose (fat) tissue, where acetyl-CoA is converted into fatty acids, which can then be esterified to form triglycerides.hese lipids are essential for various biological functions, including energy storage, cell membrane structure, and signaling.herefore, the assertion that most organisms cannot synthesize lipids is incorrect.
Conclusion:
he false statement is D: “Most organisms are unable to synthesize lipids.”n reality, lipid synthesis is a fundamental metabolic process present in a wide range of organisms.