Bio Ch 34

the process by which nutrients enter the body through the cells lining the digestive tract

an enzyme, found in saliva and pancreatic excretions, that catalyzes the breakdown of starch

a liquid secretion, produced by the liver, that is stored in the gallbladder and released into the small intestine during digestion; consists of a complex mixture of salts, water, and cholesterol

a number derived from an individual's height and weight that is used to estimate body fat

the amount of energy required to raise the temperature of one gram of water by one degree Celsius

a unit used to measure the energy content of foods; it is the amount of energy required to raise the temperature of one liter of water one degree Celsius; also called a kilocalorie, equal to 1000 calories

literally "meat eater;" a predatory organism that feeds on herbivores or other carnivores; a secondary (or higher) consumer

the process by which particles of food within the digestive tract are exposed to enzymes and other digestive fluids that break down large molecules into smaller subunits

a digestive hormone produced by the small intestine that stimulates the release of pancreatic enzymes

a particle produced by the cells of the small intestine, consisting of proteins, triglycerides, and cholesterol; transports the products of lipid digestion into the lymphatic system and ultimately the circulatory system

an acidic, souplike mixture of partially digested food, water, and digestive secretions that is released from the stomach into the small intestine

the process by which food is physically and chemically broken down into molecules that can be absorbed by cells

a group of organs responsible for ingesting food, digesting food into simple molecules that can be absorbed into the circulatory system, and expelling undigested wastes from the body

the first section of the small intestine, in which most food digestion occurs, receives chyme from the stomach, buffers and enzymes from the pancreas, and bile from the liver and gallbladder

the expulsion of indigestible materials from the digestive tract, through the anus, and outside the body

a flap of cartilage in the lower pharynx that covers the opening to the larynx during swallowing; directs food into the esophagus

a muscular, tubular portion of the mammalian digestive tract located between the pharynx and the stomach; no digestion occurs in the esophagus

an amino acid that is a required nutrient; the body is unable to manufacture these, so they must be supplied in the diet

a fatty acid that is a required nutruent; the body is unable to manufacture these, so they must be supplied in the diet

any nutrient that cannot be synthesized by the body, including certain amino acids and fatty acids, vitamins, minerals, and water

the physical and chemical breakdown of food that occurs outside a cell, normally in a digestive cavity

semisolid waste material that remains in the intestine after absorption is complete and is voided through the anus; they consist principally of indigestible wastes and other bacteria

a membranous sac, within a single cell, in which food is enclosed; digestive enzymes are released into this, where intracellular digestion occurs

a small sac located next to the liver that stores and concentrates the bile secreted by the liver; it is released from the gallbladder to the small intestine through the bile duct

one of numerous small glands in the stomach lining; contains cells that secrete mucus, hydrochloric acid, or pepsinogen (the inactive form of the protease pepsin)

a hormone produced by the stomach that stimulates acid secretion in response to the presence of food

a saclike chamber with digestive functions, found in such invertebrates such as cnidarians (sea jellies, anemones, and related animals); a single opening serves as both the mouth and the anus

literally "plant eater"; an animal that feeds directly and exclusively on producers; a primary consumer

the movement of food into the digestive tract, usually through the mouth

the chemical breakdown of food within single cells

a lymph capillary; found in each villus of the small intestine

the inability to digest lactose (milk sugar) because lactase, the enzyme that digests lactose, is not produced in sufficient amounts; symptoms include bloating, gas pains, and diarrhea

the final section of the digestive tract; consists of the colon and the rectum, where feces are formed and stored

an enzyme that catalyzes the breakdown of lipids such as fats

an organ with varied functions, including bile production, glycogen storage, and the detoxification of poisons

a membrane-bound organelle containing intracellular digestive enzymes

the process by which food in the digestive tract is physically broken down into smaller pieces

the speed at which cellular reactions that release energy occur

a microscopic projection of the plasma membrane, which increases the surface area of the cell

an inorganic substance, especially one in rocks or soil, or dissolved in water; sodium, calcium, and potassium are essential nutrients that must be obtained in the diet

the opening through which food enters a tubular digestive system

a substance acquired from the environment and needed for the survival, growth, and development of an organism

an organism that consumes both plants and animals

a combined exocrine and endocrine gland located in the abdominal cavity next to the stomach; the endocrine portion secretes the hormones insulin and glucagon, which regulates glucose concentration in the blood; the exocrine portion secretes pancreatic juice (a mixture of enzymes, water, and sodium bicarbonate) into the small intestine; the bicarbonate neutralizes acidic chyme entering the intestine from the stomach

a mixture of water, enzymes, and sodium bicarbonate released by the pancreas into the small intestine

rhythm coordinated contractions of the smooth muscles of the digestive tract that move substances through the digestive tract

in vertebrates, a chamber that is located at the back of the mouth, shared by the digestive and respiratory systems; in some invertebrates, the portion of the digestive tube just posterior to the mouth

an enzyme that digests proteins

the terminal portion of the vertebrate digestive tube where feces are stored until they are eliminated

a herbivorous animal with a digestive tract that includes multiple stomach chambers, one of which contains cellulose-digesting bacteria, and that regurgitates the contents ("cud") of the first chamber for additional chewing

a hormone produced by the small intestine that stimulates the production and release of digestive secretions by the pancreas and liver

the portion of the digestive tract, located between the stomach and large intestine, in which most digestion and absorption of nutrients occur

a circular ring of muscle surrounding a tubular structure, such as the esophagus, stomach, or intestine; its contraction and relaxation controls the movement of materials through the tube

the muscular sac between the esophagus and small intestine where food is stored and mechanically broken down and in which protein digestion begins

a finger-like projection of the wall of the small intestine that increases its absorptive surface area

one of a group of diverse chemicals that must be present in trace amounts in the diet to maintain health; used by the body in conjunction with enzymes in a variety of metabolic reactions