Two carbon atoms come into the citric acid cycle from each acetyl group, representing four out of the six carbons of one glucose molecule. Two carbon dioxide molecules are released on each turn of the cycle; however, these do not necessarily contain the most recently-added carbon atoms. The two acetyl carbon atoms will eventually be released on later turns of the cycle; thus, all six carbon atoms from the original glucose molecule are eventually incorporated into carbon dioxide. Each turn of the cycle forms three NADH molecules and one FADH 2 molecule. These carriers will connect with the last portion of aerobic respiration to produce ATP molecules. One GTP or ATP is also made in each cycle. Several of the intermediate compounds in the citric acid cycle can be used in synthesizing non-essential amino acids; therefore, the cycle is amphibolic (both catabolic and anabolic).
Answer- Fructose does not stimulate the release of insulin. The reduced insulin/glucagon ratio stimulates gluconeogenesis and inhibits glycolysis. That is, glucagon dominates the picture, increasing fructose bisphosphatase activity and leading to formation of glucose. Gluconeogenesis occurs only if fructose in pure form is consumed. However, the more usual situation is consumption of fructose as sugar as a sweetener in a “normal” meal. In other words, fructose is consumed together with starch or sugar. This leads to increases in blood sugar and insulin levels directly with a rapid cessation of gluconeogenesis.