Why is the citric acid cycle called a "cycle"?

In step 3 of the citric acid cycle, the enzyme isocitrate dehydrogenase is regulated by NADH. Compare and contrast the regulation of this enzyme with the regulation of phosphofructokinase in glycolysis.

In the citric acid cycle, an enzyme oxidizes malate to oxaloacetate, with the production of NADH and the release of H+. You are studying this reaction using a suspension of bean cell mitochondria and a blue dye that loses its color as it takes up H+. You set up reaction mixtures with mitochondria, dye, and three different concentrations of malate (0.1 mg/L, 0.2 mg/L, and 0.3 mg/L). Which of the following graphs represents the results you would expect, and why?

Which of the following processes generates most of the NADH that delivers electrons to the electron transport chain?

In the citric acid cycle, for each pyruvate that enters the cycle, one ATP, three NADH, and one FADH₂ are produced. For each glucose molecule that enters glycolysis, how many ATP, NADH, and FADH₂ are produced in the citric acid cycle?

Where do the reactions of the citric acid cycle occur in eukaryotic cells?

Which of the following represents the major energy-related accomplishment of the citric acid cycle, even though it is not the only energy-related accomplishment?