14 Translation: Synthesis of Proteins Proteins are produced by the process of translation, which occurs on ribosomes and is directed by messenger RNA (mRNA). The genetic message encoded in DNA…

28 Gluconeogenesis and Maintenance of Blood Glucose Levels During fasting, many of the reactions of glycolysis are reversed as the liver produces glucose to maintain blood glucose levels. This process…

33 Metabolism of Ethanol Ethanol is a dietary fuel that is metabolized to acetate principally in the liver, with the generation of reduced nicotinamide adenine dinucleotide (NADH). The principal route…

45 Metabolism of Muscle at Rest and during Exercise There are three types of muscle cells: smooth, skeletal, and cardiac. In all types of muscle, contraction occurs via an actin/myosin…

1 Metabolic Fuels and Dietary Components Fuel Metabolism. We obtain our fuel primarily from the macronutrients (i.e., carbohydrates, fats, and proteins) in our diet. As we eat, our foodstuffs are…

26 Formation and Degradation of Glycogen Glycogen is the storage form of glucose found in most types of cells. It is composed of glucosyl units linked by α-1,4-glycosidic bonds, with…

6 Amino Acids in Proteins Proteins have many functions in the body. They serve as transporters of hydrophobic compounds in the blood, as cell adhesion molecules that attach cells to…

46 Metabolism of the Nervous System The nervous system consists of various cell types. The most abundant cell in the nervous system is the glial cell, which consists of astrocytes…

35 Protein Digestion and Amino Acid Absorption Proteolytic enzymes (also called proteases) break down dietary proteins into their constituent amino acids in the stomach and the intestine. Many of these…

4 Water, Acids, Bases, and Buffers Approximately 60% of our body is water. It acts as a solvent for the substances we need, such as K+, glucose, adenosine triphosphate (ATP),…