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A&P, Chapter 22
Term | Definition |
---|---|
Metabolism | refers to all the chemical reactions that occur in an organism |
Cellular metabolism | chemical reactions within cells |
Catabolism | the breakdown of organic substrates in the body |
Anabolism | the synthesis of new organic molecules |
Metabolic turnover | The continuous breakdown and replacement of organic materials within cells |
Nutrient pool | an accessible reserve of organic substrates that can be used for metabolic turnover or energy production |
Acetate | the common substrate for mitochondria, 2-carbon molecule |
Acetyl-CoA | An acetyl group bound to coenzyme A, a participant in the anabolic and catabolic pathways for carbohydrates, lipids, and many amino acids |
Acetyl group | CH3CO |
Citric Acid | An important intermediate in the Citric acid cycle which breaks down glucose into water and carbon dioxide when oxygen is present. The acid contains 3 carboxyl group, has the chemical formula of C6H8O7, and is found in citrus fruits (oranges,lemons) |
Citric acid cycle | The reaction sequence that occurs in the matrix of mitochondria; In the process, organic molecules are broken down, carbon dioxide molecules are released, and hydrogen atoms are transferred to coenzymes that deliver them to the electron transport system. |
NAD | Coenzyme that removes hydrogen atoms from organic substrates, each can carry 1 hydrogen atoms; nicotinamide adenine dinucleotide |
FAD | Coenzyme that removes hydrogen atoms from organic substrates, each can carry 2 hydrogen atoms; flavin adenine dinucleotide |
Oxidative phosphorylation | The process in cell metabolism by which respiratory enzymes in the mitochondria synthesize ATP from ADP and inorganic phosphate during the oxidation of NADH by molecular oxygen. Produces 95% of the ATP used by cells. |
Electron Transport System (ETS) | The cytochrome system responsible for aerobic energy production in cells; a complex bound to the inner mitochondrial membrane. |
Cytochrome | A pigment component of the electron transport system; a structural relative of heme. |
ATP synthase | is an important enzyme that provides energy for the cell to use through the synthesis of adenosine triphosphate (ATP). |
Glycogenesis | The formation of glycogen from glucose. occurs in muscle and liver cells when there is more than enough glucose to meet energy needs |
Glycogenolysis | The release of glucose from glycogen. |
Gluconeogenesis | synthesis of glucose from noncarbohydrate precursors, such as pyruvate, amino acids and glycerol. Takes place largely in liver and serves to maintain blood glucose under conditions of starvation or intense exercise. |
Glycolysis | The initial metabolic pathway of cellular respiration in which a series of reactions happening in the cytosol results in the conversion of a glucose into pyruvic acid, and the concomitant production of a relatively small amount of ATP. |
Salivary amylase | is a salivary enzyme that breaks down complex carbohydrates into a mixture of disaccharides and trisaccharides. |
Pancreatic alpha-amylase | This enzyme has the same functions as salivary amylase, which was deactivated by denaturation in the stomach. |
Maltase | Enzyme that is broken down into maltose. |
Sucrase | Enzyme that is broken down into sucrose. |
Lactase | Enzyme that is broken down into lactose. |
Flatus | intestinal gas. |
Pyruvate | The ion formed by the dissociation of pyruvic acid, a 3-carbon compound produced by glycolysis. |
Lingual Lipase | This enzyme attacks triglycerides, breaking them down into monoglycerides and fatty acids. |
Pancreatic lipase | They speed up the conversion of dietary triglyceride substrates such as in oils into monoglycerides and free fatty acids (with the presence of water molecules) |
Bile Salts | Steroid derivatives in bile; responsible for the emulsification of ingested lipids. |
Emulsification | The breaking down of large lipid drops into tiny drops. |
Micelle | A droplet with hydrophilic portions on the outside; a spherical aggregation of bile salts, monoglycerides, and fatty acids in the lumen of the intestinal tract. |
Chylomicrons | Relatively large droplets that may contain triglycerides, phospholipids, and cholesterol in association with proteins; synthesized and released by intestinal cells and transported to the venous blood by the lymphatic system. |
Lipoprotein | A compound containing a relatively small lipid bound to a protein. |
Lipoprotein lipase | Enzyme that breaks down the chylomicrons and releases fatty acids and monoglycerides that can diffuse into the interstitial fluid. |
Low-density lipoproteins (LDLs) | A lipoprotein responsible for delivering cholesterol to peripheral tissues. |
High-density lipoproteins (HDLs) | A lipoprotein with a relatively small lipid content; responsible for the movement of cholesterol from peripheral tissues to the liver. |
Lipolysis | The catabolism of lipids as a source of energy. |
Beta-oxidation | Fatty acid catabolism that produces molecules of acetyl-CoA. |
Lipogenesis | The synthesis of lipids from non lipid precursors. |
Linolenic acid | Omega-3 fatty acid |
Omega-3 | Fatty acid. |
Linoleic acid | Omega-6 fatty acid |
Omega-6 | Fatty acid |
Essential fatty acids | Fatty acids that cannot be synthesized in the body and must be obtained from the diet. |
Pepsin | The chief digestive enzyme in the stomach, which breaks down proteins into polypeptides. |
Enteropeptidase | An enzyme released by the duodenum epithelium converting the proenzyme trypsinogen to the proteolytic enzyme trypsin. |
Trypsin | A digestive enzyme that breaks down proteins in the small intestine. |
Chymotrypsin | serine proteases from pancreas. |
Carboxypeptidase | enzymes (particularly of pancreas) that remove the c terminal amino acid from a protein or peptide. Carboxypeptidase a, will remove any amino acid, carboxypeptidase B is specific for terminal lysine or arginine. |
Elastase | A pancreatic enzyme that breaks down elastin fibers. |
Peptidases | |
Dipeptidase | |
Essential amino acids | Amino acids that cannot be synthesized in the body in adequate amounts and must be obtained from the diet. |
Amination | The attachment of an amino group to a carbon chain; performed by a variety of cells and important in the synthesis of amino acids. |
Transamination | The transferring of one amino group of one amino acid to another molecule yielding a different amino acid. |
Deamination | The removal of an amino group from an amino acid. |
Urea | A relatively harmless water-soluble compound that is excreted in urine. |
Urea cycle | The reaction sequence responsible for the production of urea. |
Absorptive state | Period following a meal; when nutrient absorption is underway |
Postabsorptive state | Period when nutrient absorption is not underway, and your body must rely on internal energy reserves to continue meeting its energy demands. |
Ketone bodies | Keto acids produced during the catabolism of lipids and some amino acids; specifically, acetone, acetoacetate, and beta-hydroxybutyrate. |
Balanced diet | Contains all the ingredients needed to maintain homeostasis. |
Malnutrition | An unhealthly state produced by inadequate dietary intake or absorption of nutrients, calories, and/or vitamins. |
MyPyramid.gov Steps to a Healthier You | Food pyramid |
Calorie | unit of heat energy that is equal to the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Centigrade at 1 atmospheric pressure. |
Joules | One joule=0.239 calories |
Kilocalorie | a measure of heat energy that is equal to the amount of heat needed to raise the temperature of one kilogram of water by one degree Centigrade at one atmospheric pressure. |
Kilojoule (KJ) | |
Complete proteins | protein that contain all essential amino acid in sufficient quality to maintain balance and growth |
Incomplete proteins | protein that is deficient I one or more of the essential amino acids. |
Eating disorders | psychological problems that result in inadequate or excessive food consumption. Examples include anorexia nervosa and bulimia. |
Anorexia | persistent loss of appetite |
Anorexia nervosa | Eating disorder characterized by a desire to lose, or not gain, weight through starvation, due to a distorted view of the victim's own body. There are typically two types; strict diet and exercise, and binging and purging. |
Bulimia | An eating disorder characterized by binge eating that is followed by feelings of guilt, depression, and self condemnation. It is often associated with steps taken to lose weight, such as self-induced vomiting, the use of laxatives, dieting, or fasting. |
Obesity | Being 20% over ideal weight, because it is at this point that serious health effects appear. |
Regulatory obesity | Most common form of obesity, results from failure to regulate food intake so that appetite, diet, and activity are in balance. |
Metabolic obesity | Relatively rare case of obesity, the condition is secondary to some underlying bodily malfunction that affects cell and tissue metabolism. |
Phenylketonuria (PKU) | An inborn error of metabolism where phenylalanine cannot be converted to tyrosine, due to the lack of the enzyme phenylalanine hydroxylase present to execute the reaction. |
Protein deficiency disease | Protein synthesis decreases throughout the body. As protein synthesis in the liver fails to keep pace with the breakdown of plasma proteins, plasma osmolarity falls. The longer a person remains in the state the more severe the ascite and edema that result |
Kwashiorkor | a form of malnutrition due to a protein deficiency in the diet that typically affects young children in tropical regions. |
Ketosis | An abnormal elevation in the blood concentration of ketone bodies that does not necessarily produce acidosis. |
Ketoacidosis | A reduction in the pH of body fluids due to the presence of large numbers of ketone bodies. |
Uric acid | |
Nitrogenous wastes | Organic waste products of metabolism that contain nitrogen, such as urea, uricacid, and creatinine. |
Gout | |
Gouty arthritis | |
Energetics | |
Basal metabolic rate (BMR) | The rate of metabolism (expressed as oxygen consumption or heat production) under resting or basal conditions (14 to 18 hours after eating) |
Thermoregulation | Homeostatic maintenance of body temperature. |
Feeding center | |
Satiety center | |
Neuropeptide Y (NPY) | |
Ghrelin | |
Leptin | |
Radiation | |
Convection | |
Evaporation | |
Insensible Perspiration | Evaporative water loss by diffusion across the epithelium of the skin or evaporation across the alveolar surfaces of the lungs. |
Sensible Perspiration | Water loss due to secretion by sweat glands. |
Conduction | |
Heat-loss center | |
Heat-gain center | |
Behavioral changes | |
Vasodilation and shunting of blood | |
Sweat production | |
Respiratory heat loss | |
Nonshivering thermogenesis | |
Shivering thermogenesis | |
Countercurrent exchange | The transfer of heat, water, or solutes between two fluids that travel in opposite directions. |