Protein X is produced in the liver cells of the body. However, this protein is not produced within the intestine. Which statement best explains why? A. The gene for protein X is present in the intestinal cells, but it is not expressed.

B. The gene for protein X is not present in the intestinal cells.

C. The gene for protein X is present in the liver cells, but it is not expressed.

D. The gene for protein X is not present in the liver cells

Answer: The liver is an essential metabolic organ, and its metabolic activity is tightly controlled by insulin and other metabolic hormones. Glucose is metabolized into pyruvate through glycolysis in the cytoplasm, and pyruvate is completely oxidized to generate ATP through the TCA cycle and oxidative phosphorylation in the mitochondria.

Explanation: fasted state, the liver secretes glucose through both breakdown of glycogen (glycogenolysis) and de novo glucose synthesis (gluconeogenesis). During pronged fasting, hepatic gluconeogenesis is the primary source of endogenous glucose production. Fasting also promotes lipolysis in adipose tissue to release nonesterified fatty acids which are converted into ketone bodies in the liver though mitochondrial β oxidation and ketogenesis. Ketone bodies provide a metabolic fuel for

Extra: extrahepatic tissues. Liver metabolic processes are tightly regulated by neuronal and hormonal systems. The sympathetic system stimulates, whereas the parasympathetic system suppresses, and hepatic.