Question

which statement is correct with regard to redox (oxidation - reduction) reactions? a molecule is oxidized if it loses electrons. a molecule is reduced if it loses electrons. an electron donor is called a oxidizing agent. an electron acceptor is called an reducing agent. 2 multiple choice 5 points starting with one molecule of glucose, the
et\ products of glycolysis include 2 nad+, 2 pyruvate, and 2 atp. 2 nadh, 2 pyruvate, and 2 atp 6 co2, 6 h2o, 36 atp, and 2 citrate. 6 co2, 6 h2o, 2 atp, and 2 pyruvate. 3 multiple choice 5 points most of the energy that enters electron transport enters as atp fadh2 and nadh. pyruvate. glucose 4 multiple choice 5 points including the preparatory conversion to acetyl coa, how many molecules of carbon dioxide (co2) would be released from the complete aerobic respiration of a molecule of sucrose (c12h22o11), a disaccharide? 2 6 12 32

Explanation:

• Question 1: In redox reactions, oxidation is the loss of electrons (so a molecule is oxidized if it loses electrons). Reduction is the gain of electrons. An electron donor is a reducing agent and an electron acceptor is an oxidizing agent.
• Question 2: Glycolysis of one glucose molecule gives 2 NADH (from the reduction of 2 NAD+), 2 pyruvate, and a net gain of 2 ATP (after accounting for the ATP used in the early steps of glycolysis).
• Question 3: FADH₂ and NADH carry high - energy electrons that enter the electron transport chain. ATP is the end - product of oxidative phosphorylation (not the input to the electron transport chain). Pyruvate is converted to acetyl - CoA before entering the citric acid cycle, and glucose is broken down in glycolysis before its products enter the later stages of cellular respiration.
• Question 4: Sucrose (\(C_{12}H_{22}O_{11}\)) can be thought of as two glucose - like units (since glucose is \(C_6H_{12}O_6\)). In the preparatory conversion to acetyl - CoA (pyruvate decarboxylation) and the citric acid cycle, each glucose molecule (in terms of carbon atoms) will release 6 \(CO_2\) molecules. For a sucrose molecule (equivalent to 2 glucose - like units in terms of carbon counting for \(CO_2\) release), the number of \(CO_2\) molecules released is \(12\) ( \(2\times6\)).

Answer:

1. A. A molecule is oxidized if it loses electrons.
2. 2 NADH, 2 pyruvate, and 2 ATP.
3. FADH2 and NADH.
4. 12.