digestive system quiz Flashcards
what is mechanical digestion
breaking down food into smaller particles but not acting on the bond level
what is chemical digestion
breaking the bonds in the food chemically
what is an enzyme
a protein in the body that speeds up the digestion process CHEMICALLY
what enzyme breaks down carbohydrates
amylase
what enzyme breaks down proteins
pepsin
what enzyme breaks down fats
lipases
where is amylase found
in the mouth and pancreas
where is pepsin found
in the stomach, secreted by chief cells
what are the three macromolecules
carbohydrates, protein, and fats (lipids)
what is a polymer
large molecules that are in fact to large to be absorbed into the bloodstream as they are
what is a monomer
small molecules that can be absorbed into the bloodstream- polymers are broken into monomers
how many salivary glands do we have
three- parotid, submandibular, sublingual
what does food turn into once it reaches the throat
a “bolus”
is peristalsis controlled by the CNS or ENS
ENS- meaning it is not voluntary. once the bolus has entered your esophagus, you have no control over it
is swallowing controlled by the CNS or ENS
CNS- meaning it is voluntary.
what is peristalsis
the involuntary contraction and relaxation of muscles throughout your digestive tract (present in the esophagus)
what enzyme is in the mouth and what does is chemically digest
salivary amylase, breaking down starch
what is the epiglottis
it is a piece of cartilage that moves to cover the trachea so that food enters the esophagus and NOT the trachea (prevents choking)
what are the three functions of the stomach
disinfecting & storing food, as well as digesting protein using pepsin
what is the acid in the stomach
HCl, and it has a pH of 2
what stops the stomach from digesting itself
mucus secreted by stomach cells that protect the lining of the stomach
what does HCl do in the stomach
kills microorganisms, converts pepsinogen to pepsin, and aids in the dissolving of food
what is the bolus now called in the stomach
chyme
what cells secrete pepsinogen
chief cells (converted to pepsin in the presence of HCl)
what are the accessory organs of digestion
liver, gallbladder, pancreas
what three sections is the small intenstine comprised of
duodenum, jejunum, ileum
where is bile secreted
in the liver- however it is produced by the liver
what is the role of the pancreas in the digestive system
to release pancreatic juices (comprised of amylase, trypsin, and chymotripsin) to help further digest food in the duodenum
how do nutrients get absorbed into the bloodstream
diffusion
what are villi and microvilli
small finger-like projections that line the inner wall of the small intestine (increases surface area for absorption) that allow easy diffusion into the capillaries that coat the intestine
what is the primary purpose of the colon
water absorption
what type of materials pass from the small intestine to the colon
undigested and unabsorbed materials
are the muscle contractions in the colon
yes, to help keep feces moving
what vitamin is absorbed in the colon
vitamin K, produced by E. coli bacteria that reside in the colon
why does constipation happen and why does diahrrea happen
constipation = too much water reabsorbed
diahrrea = not enough water reabsorbed
is the rate of transit of materials through the colon positively or negatively correlated with their fiber content
positively- more fiber in the foods you eat allows for faster and more comfortable bowel movements
what are feces comprised of
undigested material, cellulose, roughage/fiber, masses of bacter & water
what indicator is used to identify starch
iodine solution - black = positive
what indicator is used to indentify protein
biuret solution - violet = positive
what indicator is used to identify lipids
litmus - blue in basic solutions, pink in acidic solutions
