"Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma."
This includes the study of the chemical reactions and metabolic pathways that occur in the digestive system for the breakdown and absorption of food nutrients, such as carbohydrates, lipids, and proteins.
Introduction to biochemistry: This includes the definition of biochemistry, its historical development, and its importance in modern science.
Basic chemical principles: This includes the structure of atoms, chemical bonds, chemical reactions, and the properties of chemical reactions.
Cell structure and functions: This includes the structure of cells, cell organelles, cellular transport, and cellular energy metabolism.
Proteins: This includes the structure and functions of proteins, protein synthesis, and protein purification.
Enzymes: This includes the classification, characteristics, and mechanisms of enzymes, enzyme kinetics, and enzyme regulation.
Carbohydrates: This includes the structures and functions of carbohydrates, carbohydrate metabolism, and glycobiology.
Lipids: This includes the structures and functions of lipids, lipid metabolism, and lipidomics.
Nucleic acids: This includes the structures and functions of nucleic acids, DNA replication, transcription, and translation.
Metabolism: This includes the biochemical pathways of metabolism, including glycolysis, the Krebs cycle, and oxidative phosphorylation.
Energy metabolism: This includes the reactions involved in the production of ATP, the role of mitochondria in cellular respiration, and the regulation of energy metabolism.
Digestion: This includes the anatomy and physiology of the digestive system, the digestive enzymes and their functions, and the digestion and absorption of nutrients.
Nutrients: This includes the classification, sources, functions, and deficiency symptoms of nutrients such as carbohydrates, lipids, proteins, vitamins, and minerals.
Hormones: This includes the major hormones involved in digestion and their physiological roles, including insulin, glucagon, gastrin, and cholecystokinin.
Microbial role in digestion: This includes the role of gut microbiota in digestion, their metabolism, and their impact on human health.
Food processing: This includes the effect of food processing on the nutrient content and bioavailability of nutrients.
Nutritional Biochemistry: The study of the chemical compounds in food and their effects on the body's metabolism.
Enzymology: The study of enzymes and their catalytic functions in metabolic pathways.
Medicinal Biochemistry: The study of the chemical properties of drugs and their interaction with biological molecules.
Molecular Biology: The study of the structure and function of biological molecules, especially nucleic acids and proteins.
Proteomics: The study of the structure, function, and interactions of proteins in the body.
Metabolomics: The study of the chemical processes that occur within living organisms and how they change over time.
Neurochemistry: The study of the chemistry of the nervous system and the chemicals involved in neural activity.
Lipid Biochemistry: The study of the chemical properties, metabolism, and function of lipids in the body.
Glycobiology: The study of the structure, function, and biosynthesis of carbohydrates in the body.
Bioenergetics: The study of energy storage and transfer in biological systems.
Structural Biochemistry: The study of the three-dimensional structure of biological molecules and the relationship between structure and function.
Immunobiochemistry: The study of the chemical and molecular basis of the immune system and its interactions with pathogens.
"Digestion is often divided into two processes based on how food is broken down: mechanical and chemical digestion."
"The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes."
"Mechanical digestion takes place in the mouth through mastication and in the small intestine through segmentation contractions."
"In chemical digestion, enzymes break down food into the small compounds that the body can use."
"Mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact of saliva."
"Saliva, a liquid secreted by the salivary glands, contains salivary amylase, an enzyme which starts the digestion of starch in the food; the saliva also contains mucus, which lubricates the food, and hydrogen carbonate, which provides the ideal conditions of pH (alkaline) for amylase to work, and electrolytes (Na+, K+, Cl−, HCO−3)."
"About 30% of starch is hydrolyzed into disaccharide in the oral cavity (mouth)."
"It will then travel down the esophagus and into the stomach by the action of peristalsis."
"Gastric juice mainly contains hydrochloric acid and pepsin. In infants and toddlers, gastric juice also contains rennin to digest milk proteins. As the first two chemicals may damage the stomach wall, mucus and bicarbonates are secreted by the stomach."
"The stomach provides a slimy layer that acts as a shield against the damaging effects of chemicals like concentrated hydrochloric acid while also aiding lubrication. Hydrochloric acid provides acidic pH for pepsin."
"At the same time protein digestion is occurring, mechanical mixing occurs by peristalsis, which is waves of muscular contractions that move along the stomach wall. This allows the mass of food to further mix with the digestive enzymes."
"Pepsin breaks down proteins into peptides or proteoses, which is further broken down into dipeptides and amino acids by enzymes in the small intestine."
"When the pyloric sphincter valve opens, partially digested food (chyme) enters the duodenum."
"Digestive enzymes from the pancreas and bile juice from the liver mix with the chyme in the duodenum, and then the digestion process continues in the small intestine."
"95% of nutrient absorption occurs in the small intestine."
"Water and minerals are reabsorbed back into the blood in the colon (large intestine) where the pH is slightly acidic (about 5.6 ~ 6.9)."
"Some vitamins, such as biotin and vitamin K (K2MK7) produced by bacteria in the colon, are also absorbed into the blood in the colon."
"Absorption of water, simple sugar, and alcohol also takes place in the stomach."
"Waste material is eliminated from the rectum during defecation."