After this section, you should be able to:
Define metabolism and describe the relationship of the various types of chemical reactions to the overall metabolism of the cell.
Recognize the role of enzymes in biochemical reactions.
Identify the two major methods of controlling metabolism and differentiate between these two methods.
Recognize the major biochemical pathways that cells utilize to regenerate ATP and generate macromolecules (lipids, proteins, glycogen, nucleic acids) for the cell; and the role of these macromolecules in normal physiological functions for the cell and tissues of the body.
Understand and explain the differences between oxidative and substrate-level phosphorylation.
Describe and differentiate the fuel sources (carbohydrates, fats, amino acids) used for the regeneration of ATP within the energetic pathways of the cell and tissues based on the availability of oxygen and the fuel source metabolized along with the differences in total ATP generated and the relative effiency of the pathway.
Outline and identify the steps to the biochemical reactions of glycolysis with awareness to the rate-limiting steps and enzymes within the metabolic pathway.
Understand and explain the fates of pyruvate following glycolysis based on the overall amounts of pyruvate and availability of oxygen to the cell/tissues of the body and the role of the Cori Cycle in the fates of pyruvate.
Outline and identify the steps to the biochemical reactions of the Krebs (TCA) cycle with awareness to the rate-limiting steps and enzymes within the metabolic pathway.
Outline the transport of hydrogen ions through the electron transport chain that leads to the oxidative phosphorylation process to regenerate ATP.
Differentiate between the biochemical pathways of glycolysis, glycogenesis, glycogenolysis, gluconeogenesis, lipolysis and β-oxidation, lipogenesis, protein synthesis and deamination; as it relates to products, reactants, by-products and homeostatic regulation.
Determine the basal metabolic rate (BMR) for an individual and the regulatory factors of BMR for any individual.
List and describe the major and minor nutrients that are required in a “balanced diet” and the difference between labeling of major versus minor nutrient.
Differentiate between the various types of carbohydrates and roles of type with the physiology of cells and tissues of the body.
Differentiate between the various types of fats and lipids and roles of type with the physiology of cells and tissues of the body.
Differentiate between the various types of amino acids, being able to explain why some are termed essential while other non-essential, and roles of type with the physiology of cells and tissues of the body.
Metabolism is the sum total of all biochemical processes within the body at any given moment of any given day. These reactions will function based on the laws of thermodynamics and principles of mass conversions that can be either breaking down molecules (catabolism) into smaller component molecules, build-up molecules (anabolic) from smaller components, changing the arrangement of atoms within the molecule (isomerization) or activating a molecule through increasing energetic state (kination). When we generally look at metabolism through the principal reactions that release energy (catabolic), or utilize energy (anabolic), that occurs when there is breaking, or building, bonds between atoms. The means by which we measure this energy change in a single reaction is through the unit calorie (or Calorie when examining the sum total of reactions).
Based on energetics of reaction and need to ensure that metabolic processes occur in a timely and organized fashion all metabolic processes are controlled by an enzyme, or more correctly a series of enzymes within the cells and tissues of the body. In turn hormones secreted by neuroendocrine tissues systematically activate or inhibit the enzymes that control the metabolic processes regulate these processes. Before we cover the major topics of metabolism, especially bioenergetics and synthesis of the major macromolecules (lipids, carbohydrates and proteins) we need to first understand some of the general terminology that is utilized with metabolism.