Unit 2 Flashcards
(161 cards)
digestion
mechanical and chemical breakdown of food into subunits enabling the absorption of nutrients
digestive system
organ system that breaks down food molecules into smaller subunits, absorbs nutrients and eliminates waste composed of the digestive tract and accessory organs
esophagus
section of the digestive tract between the mouth and the stomach
peristasis
coordinated muscular contraction that force food down the digestive tract
stomach
expandable muscular organ that stores mechanically breaks down and digests proteins in food
chyme
the acidic soup of the partially digested food that leaves the stomach and enters the small intestines
small intestine
the organ in which the bulk of chemical digestion and absorption of food occurs
pancreas
organ that helps digestion by producing enzymes such a lipase that act in the small intestine and by secreting a juice that neutralized acidic chyme
liver
organ that aids digestion by producing bile salts that emulsify fats
bile salts
chemical produce by the liver and stored by the gallbladder that emulsify fats so that they can be chemically digested by enzymes
emulsify
to break up large fat globules into smaller fat droplets the at be fore efficiently chemically digested by enzymes
absorption
the uptake of digested food molecules by the epithelial cells lining the small intestine
gall bladder
organ that stored bile salts and releases them as needed into the small intestine
villi
finger like projections of folds in the lining of the small intestine that are responsible for most nutrient and water absorption
large intestine
the last organ of the digestive tract in which remaining water is absorbed and solid stool is formed
stool
solid waste material eliminated from the digestive tract
simple diffusion CH 3
movement of small hydrophobic molecules across a membrane from an area of higher concentration to an area of lower concentration simple diffusion does not require an input of energy
transport proteins
proteins involved in the movement of molecules across the cell membrane
facilitated diffusion
process by which large or hyrohilic solute move across a membrane from an area of higher concentration to an area of lower concentration with the help of transport proteins facilitated diffusion does not require an input of energy
active transport
energy requiring process by which solutes are pumped from a area of lower concentration to an area of higher concentration with the help of transport proteins
if a solute is moving through a phospholipid bilayer from an area of higher concentration to an area of lower concentration with out the assistance of a protein the manner of transport is…
simple diffusion
what do simple diffusion and facilitated diffusion have in common
they both go from a higher concentration to a lower
what do active transport and facilitated diffusion have in common
both use transport proteins
why does facilitated diffusion require membrane transport proteins while simple diffusion does not
,because the molecules are larger and hydrophilic