Chapter 5 Flashcards
Absorption
Movement of dissolved substances such as digested food and oxygen across a plasma membrane into the interior of a cell
Alimentary canal
Muscular tube through which food passes; in humans it extends from the mouth to the anus and includes the pharynx, oesophagus, stomach, duodenum, and small and large intestines; also known as the digestive tract or gut
Amylase
Group of enzymes that break down the polysaccharides starch and glycogen into smaller units
Anus
Posterior or terminal opening of the alimentary canal through which faeces are expelled from the body
Autotrophic
Describes an organism that, given a source of energy, can produce its own food from simple inorganic substances; also known as a producer
Autotrophs
Organisms that, given a source of energy, can produce their own food from simple inorganic substances; also known as producers
Bile
Secretion produced by the liver and stored in the gall bladder that contains bile salts that emulsify lipids
Bile duct
Tube that transports bile from the gall bladder
Bolus
Rounded mass of food, formed during chewing and ready for swallowing
Carnivores
Organisms that kill and eat animals
Cellular respiration
Process of converting chemical energy of food into a form usable by cells, typically ATP
Chloroplasts
Chlorophyll-containing organelles that occur in the cytosol of cells of specific plant tissues
Chyme
Soupy mixture of food, saliva and gastric juice found in the stomach
Colon
Portion of the large intestine leading from the small intestine to the rectum
Cystic fibrosis
A condition, inherited as an autosomal recessive, in which an affected person produces abnormal mucus secretions
Digestion
Chemical breakdown of large organic molecules into smaller units that can pass across plasma membranes
Digestive system
Alimentary canal and associated organs that secrete chemicals into the canal
Duodenum
Portion of the small intestine leading from the stomach and into which secretions from the pancreas and the liver are released
Emulsification
Breakdown of large fat droplets into smaller fat droplets
Enzymes
Typically, specific proteins that act as catalysts to increase the rate of a particular chemical reaction in living organisms
Faeces
Undigested material eliminated from the gastrointestinal tract
Foregut fermenters
Herbivorous mammals in which bacterial digestion of plant material occurs in a greatly enlarged stomach or oesophagus
Gall bladder
Organ in which bile is stored
Gastric juice
Fluid secreted by various cell types in the stomach wall; contains enzymes, water, mucus and hydrochloric acid
Herbivores
Organism that eats living plants or parts of them
Heterotrophic
Describes an organism that cannot make its own food and must ingest or absorb organic material from its environment
Heterotrophs
Organisms that ingest or absorb food in the form of organic material from their environment; also known as consumers
Ileum
Part of the small intestine leading from the jejunum to the large intestine
Jejunum
Short section of the small intestine leading from the duodenum to the ileum
Lacteals
Lymph vessels in the villi of the small intestine
Large intestine
Part of the digestive system between the small intestine and anus
Liver
In mammals, large organ located in upper abdomen and which has many functions including removal of some toxic materials from the blood, storage of glycogen and production of bile
Mucus
Lubricating substance secreted by mucous glands particularly in the alimentary canal and the bronchii
Oesophagus
Muscular tube that transports food from the pharynx at the back of the mouth to the stomach
Pancreas
Organ that secretes digestive enzymes into the duodenum and hormones into the bloodstream
Peristalsis
Movement of food along the gut by means of contraction and relaxation of muscle in the gut wall
Pepsin
Protein-digesting enzyme produced by cells in the stomach
Photosynthesis
Process by which plants trap the radiant energy of sunlight to produce carbohydrates from carbon dioxide and water
Prey
Living animal that is captured and eaten by a predator
Pyloric sphincter
A muscular opening through which food is forced from the stomach into the small intestine
Rectum
Final section of the large intestine that ends at the nu
Ruminants
Herbivorous mammals with a stomach comprising several compartments, one of which is known as the rumen where fermentation of food occurs
SA:V
(surface-area-to-volume ratio) a measure that identifies the number of units of surface area available to ‘serve’ each unit of internal volume of a cell, tissues or organism
Small intestine
Part of the alimentary canal that comprises the duodenum, jejunum and ileum, and is located between the stomach and the large intestine
Stomach
Expanded part of the gut into which the oesophagus opens
Villi
(singular = villus) small projections of tissue that function to increase surface area
