Respiration: Practice Questions

During glycolysis, what is the net yield of ATP and reduced NAD (NADH) per molecule of glucose?

During aerobic respiration, electrons are transferred along a series of carriers in the inner mitochondrial membrane. Which of the following best describes the role of oxygen in this process according to the chemiosmotic theory?

In a respirometer experiment, a student measured the oxygen uptake of germinating seeds. If the student added potassium hydroxide (KOH) to the respirometer and observed the liquid move \(15\,mm\) towards the seeds, but in a second trial without KOH, the liquid did not move, what can be concluded about the seeds?

Which molecule acts as the final electron acceptor in the electron transport chain during aerobic respiration?

Which of the following best explains the chemiosmotic theory in the context of oxidative phosphorylation?

State the specific location within a mitochondrion where the enzymes for the Krebs cycle are located and explain why the presence of mitochondrial DNA is important for the function of this organelle.

A sample of germinating seeds is placed in a respirometer. During a set period, the volume of oxygen consumed is measured as \(25.0\text{ cm}^3\) and the volume of carbon dioxide produced is measured as \(20.0\text{ cm}^3\).
Calculate the Respiratory Quotient (RQ) for these seeds and suggest which respiratory substrate is predominantly being utilized based on this value.

Explain the role of oxidative phosphorylation in the transition from reduced NAD to the production of ATP, specifically referencing the role of the electron transport chain, the generation of a proton gradient, and the function of ATP synthase according to the chemiosmotic theory.

(a) Explain the role of coenzymes in the process of aerobic respiration, with specific reference to NAD and FAD during the Krebs cycle and oxidative phosphorylation. (3)

(b) The chemiosmotic theory describes how a proton gradient is used to synthesize ATP. Describe how the mitochondrial cristae and the electron transport chain (ETC) facilitate the establishment of this gradient and the subsequent production of ATP. (4)

(c) A scientist investigates the respiration of a specific tissue. They measure the volume of oxygen consumed as \(45.0\text{ cm}^3\) and the volume of carbon dioxide produced as \(31.5\text{ cm}^3\).
Calculate the Respiratory Quotient (RQ) for this tissue and suggest, with a reason, the type of respiratory substrate being metabolized. (2)