Which of the following is an effect of insulin?

Insulin is a primary anabolic hormone that regulates glucose metabolism. When blood glucose levels rise, the pancreas secretes insulin, which binds to receptors on target cells (primarily muscle, fat, and liver cells). This binding facilitates the transport of glucose from the bloodstream into the cells. Once inside, glucose is used for energy production through glycolysis or stored as glycogen (glycogenesis) in the liver and muscles. By promoting both the uptake and utilization of glucose by cells, insulin effectively increases the rate of glucose metabolism, thereby lowering blood glucose concentrations.

A. Insulin promotes the conversion of glucose into glycogen for storage (glycogenesis), which increases, not decreases, glycogen concentration in the liver.
B. The principal function of insulin is to lower blood glucose levels by promoting its uptake into cells; glucagon is the hormone that increases blood glucose.
C. Insulin is an anabolic hormone that inhibits the breakdown of fats (lipolysis) and promotes the synthesis of fatty acids and triglycerides for storage.

1. Hall, J. E., & Hall, M. E. (2021). Guyton and Hall Textbook of Medical Physiology (14th ed.). Elsevier. Chapter 79, "Insulin, Glucagon, and Diabetes Mellitus," section "Effect of Insulin on Carbohydrate Metabolism," pp. 982-984.

2. Wilcox, G. (2005). Insulin and Insulin Resistance. The Clinical Biochemist Reviews, 26(2), 19–39. Section "Physiological Actions of Insulin," p. 20, paragraph 2.

3. MIT OpenCourseWare. (2004). 7.012 Introductory Biology, Fall 2004. Massachusetts Institute of Technology. Lecture 26 Notes: Hormones and the Endocrine System. Retrieved from https://ocw.mit.edu/courses/7-012-introductory-biology-fall-2004/resources/lecture-26-hormones-and-the-endocrine-system/ (Specifically discusses insulin's role in promoting glucose uptake and storage).