I. Digestive System Flashcards
A. function
1) break food down into component
molecules
2) to absorb molecules to be turned into structure or energy
B. types
- herbivores
- carnivores
- omnivores
B. types
1. herbivores
eat plants
- “herb” = plant, “vor” = eat
- digest plant cell: cytoplasm, cell wall
(made of cellulose) -ose = sugar - herbivores have highly specialized
digestive systems that allow them to
get way more food value out of
eating a plant than we can - protists or bacteria aid in digestion
of cellulose (plant cell walls)
^ humans can’t break down cell
walls
^ reason why -> cellulase - endosymbionts:
endo - inside
sym - with
bio - life, lives
-nt - one that does something - endosymbionts produce enzyme
cellulase to break down
polysaccharide cellulose
^ endosymbiont is an organism that
lives inside another organism - “ase” = enzyme
- “ose” = sugar molecule
- we can’t break down cellulose since
we don’t have the gene to make
enzyme cellulase - after digestion -> make sugar
- must digest food multiple times
^ food must be thoroughly mixed
with endosymbionts - herbivores have a much more
digestive tract than carnivores - must have endosymbionts to be
able to break cell walls of plants
B. types
2. carnivores
eat animals
- most parts of an animal are easily
digested - have simpler digestive tracts
- easy to eat meat and break it down
because meat eating has been
around way longer than plant eating
B. types
3. omnivores
eat plants and animals
- eat everything
- omnivores don’t have
endosymbionts
^ get nutrition from the cytoplasm in
plants instead of cell walls - cell walls provide soluble fibers
- intermediate digestive tract
complexity - humans teeth are adapted for
omnivorous diets
C. process of digestion
- mechanical digestion
- chemical digestion
C. process of digestion
1. mechanical digestion
a) physically break large pieces of food into smaller pieces
b) create larger surface area
- surface area affects every system
- breakdowns allow more and faster
digestion
- exposed surfaces
- taking a large food item and
breaking down
- surface to volume ration
C. process of digestion
2. chemical digestion
a) chemically breaks large molecules into smaller molecules (molecules instead of chunks for chemical digestion)
ex. hydrolysis (splitting with water)
^ watery in digestive tract
^ “hyd” = water, “lys” = cut, “is” = process
- polysaccharides are very stable
- cellulose and starch are made of
glucose
- glycogen store energy
- chitin is kind of like cell wall in plants
b) need enzymes to speed up the reactions hydrolysis (splitting with water)
- enzymes breaks down the bonds
- break food into molecules then it gets transported into cell membranes
- amylase starch attaches to enzymes
^ “amy” = starch
- maltase and sucrase are disaccharide
^ maltase is the sugar the sweetens
malt and sucrase is table sugar
^ in maltase, glucose goes to
mitochondria to make ATP and in
sucrase, glucose goes to
mitochondria to make ATP; fructose
goes to liver»_space; fat
D. stage of digestive process
- ingestion: getting food into body
- digestion
- absorption
- elimination
D. stage of digestive process
1. ingestion: getting food into body
- animal has to eat for digesting
D. stage of digestive process
2. digestion
chemical and mechanical breakdowns of food into molecules that can be absorbed
- once food is in the mouth, it needs to get digested to break food down in molecules
D. stage of digestive process
3. absorption
movement of food molecules into cells
^ from digestive tract into the bloodstream and then absorbed by individual cells throughout the body and used to power body or structure molecules
D. stage of digestive process
4. elimination
ridding body of unused food matter
- may be bacteria associated
