Bio 103 - Chapter 10 (2) - Pharmacgy

Explanation
In the given reaction, pyruvate is being reduced to lactate, which means it is gaining electrons. The species that causes another species to undergo oxidation by accepting its electrons is called the oxidizing agent. Therefore, in this reaction, pyruvate is acting as the oxidizing agent as it accepts electrons from NADH and gets reduced to lactate.

Explanation
The end products of glycolysis are NADH and pyruvate. Glycolysis is the process by which glucose is broken down into pyruvate. During glycolysis, glucose is converted into two molecules of pyruvate, and NAD+ is reduced to NADH. Therefore, the correct answer is NADH and pyruvate.

Explanation
The citric acid cycle, also known as the Krebs cycle, is the metabolic process where the most CO2 from the catabolism of glucose is released. This cycle takes place in the mitochondria and is the final step in the breakdown of glucose. During the citric acid cycle, acetyl-CoA is oxidized and CO2 is produced as a byproduct. This CO2 is then released as waste. Glycolysis and the oxidation of pyruvate acetyl-CoA also produce CO2, but the majority of CO2 is released during the citric acid cycle. The electron transport chain is not directly involved in the release of CO2.

Explanation
In cellular respiration, glucose molecules are broken down to produce energy. Each glucose molecule produces 6 molecules of carbon dioxide (CO2). Since there are 3 glucose molecules in this scenario, the total number of CO2 molecules produced would be 3 multiplied by 6, which equals 18. Therefore, the given answer of 24 is incorrect.

Explanation
In cellular respiration, one glucose molecule can produce a maximum of 32 ATP (adenosine triphosphate) molecules. ATP is the main energy currency of cells, and it is produced through a series of metabolic reactions. During glycolysis, two ATP molecules are generated. In the citric acid cycle, two ATP molecules are produced directly, and during oxidative phosphorylation, which occurs in the electron transport chain, a maximum of 28 ATP molecules are generated. Therefore, the total ATP production from one glucose molecule is 2 + 2 + 28 = 32 ATP molecules.

Explanation
Reducing the efficiency of cellular respiration can be beneficial under certain conditions because it allows the cell to conserve energy and resources. By slowing down the rate of cellular respiration, the cell can redirect its resources towards other important processes such as growth, repair, or defense mechanisms. This can be advantageous in situations where the cell needs to prioritize these processes over energy production. Additionally, reducing the efficiency of cellular respiration can help in conserving oxygen when it is limited, such as during periods of low oxygen availability or in certain types of cells that do not require high energy production.

Explanation
The electron transport chain is responsible for generating a proton gradient across the inner mitochondrial membrane. This gradient is then used by ATP synthase to produce ATP through a process called chemiosmosis. Therefore, the electron transport chain does not directly produce ATP, but rather provides the necessary conditions for ATP synthesis to occur.

Explanation
GTP (guanosine triphosphate) is similar to ATP (adenosine triphosphate) in structure and cellular function. Both molecules are nucleotides and have a similar structure, consisting of a sugar, a phosphate group, and a nitrogenous base. They also play important roles in cellular energy metabolism and are involved in various cellular processes, such as signal transduction and protein synthesis. Therefore, the statement that GTP is not similar to ATP in structure and cellular function is false.

Explanation
When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, it means that the glucose molecule has undergone oxidation. Oxidation is a chemical process in which a molecule loses electrons or hydrogen atoms, resulting in an increase in its oxidation state. In this case, the loss of a hydrogen atom indicates that the glucose molecule has lost electrons, making it oxidized.

Explanation
Substrate level phosphorylation is a metabolic process in which ATP is directly produced during the conversion of a substrate molecule. This occurs when a high-energy phosphate group is transferred from a substrate molecule to ADP, forming ATP. This process is different from oxidative phosphorylation, which occurs in the electron transport chain and generates ATP indirectly through the use of a proton gradient. Therefore, the given statement is true.

Explanation
Oxidative phosphorylation is the process by which ATP is produced in the mitochondria through the electron transport chain and chemiosmosis. During this process, a total of 28 ATP molecules are generated indirectly. This is because for each NADH molecule that enters the electron transport chain, 3 ATP molecules are produced, and for each FADH2 molecule, 2 ATP molecules are produced. Therefore, considering the number of NADH and FADH2 molecules produced during cellular respiration, a total of 28 ATP molecules are generated indirectly through oxidative phosphorylation.

Explanation
Glycolysis is the process by which glucose is broken down in the cytoplasm of cells to produce pyruvate, along with a small amount of ATP and NADH. This process involves a series of enzymatic reactions that result in the oxidation of glucose molecules. Therefore, the statement that glycolysis harvests chemical energy by oxidizing glucose to pyruvate is true.

Explanation
During oxidative phosphorylation, chemiosmosis is the process by which the energy released from the electron transport chain is used to pump protons across the inner mitochondrial membrane. This creates a proton gradient, which drives the synthesis of ATP by ATP synthase. Therefore, chemiosmosis directly couples electron transport to ATP synthesis, making the statement "True" correct.

Explanation
Fermentation and anaerobic respiration enable cells to produce ATP without the use of oxygen. This is because these processes occur in the absence of oxygen and utilize alternative electron acceptors, such as organic molecules, to generate ATP.

Explanation
Catabolic pathways are metabolic processes that break down complex molecules into simpler ones, releasing energy in the process. These pathways typically involve the oxidation of organic fuels, such as carbohydrates, fats, and proteins. Through a series of enzymatic reactions, these molecules are broken down, releasing energy that can be used by cells for various functions. Therefore, the statement that catabolic pathways yield energy by oxidizing organic fuels is true.