Digestive System Flashcards
refers to all chemical reactions that take place inside an organism’s body.
metabolism
The intake of food from various sources and process that convert food substances into living mater
nutrition
animals that consume organic molecules from other organisms.
Heterotrophs
Dietary Categories:
a. Herbivores: exclusive to eating plants
b. Carnivores: exclusive to eating flesh
c. Omnivores: Eat both plants and animal
d. Detritivores: Eat decaying dead bodies of plants and animals
Types of Digestive System in Animals
Single-celled organisms
Multi-cellular organisms
process their food right inside their cells. The digestion process is known
as intracellular digestion, which happen inside the cells through vacuoles. Eg. Amoeba and
paramecium.
Single-celled organisms-
Engulfing of food
phagocytosis
process nutrients by absorbing it into the bloodstream after they have
been broken down within digestive cavity while wastes are excreted out. This process is known as
extracellular digestion.
Multi-cellular organisms-
contains one-way tubes with different openings for mouth and anus.
complex alimentary
canal
assist in the digestive process.
glands
Feeding Mechanisms in Animals
a. Suspension Feeding
b. Filter Feeding
c. Substrate Feeding.
d. Fluid Feeding
e. Bulk feeding
Marine invertebrates live in abundance of floating microscopic food particles
such as plankton. Most of these organism use their body parts to move water toward a feeding
structure to sift the food suspended in water. Eg. Star fish
Suspension feeding
extract food particle and sieving it to filtering structure. Eg. Humpback whale and
clams
Filter Feeding
eating way through the soil while digesting and excreting food as they crawl.
Eg. Earthworm.
Substrate feeding
ingest food by sucking nutrient-rich fluid from living host that either plant or animal.
Eg. Humming bird, bees, mosquito, and bats
Fluid feeding
ingest large pieces of food into their mouth.
bulk feeding
“cell eating” is a process wherein cells take in large particles or solid through the
enfolding of the cell membrane to form endocytic vesicle.
phagocytosis
“cell drinking” is a process wherein a cell takes fluids by the invagination of the cell
membrane that forms a vesicle or vacuole.
pinocytosis
for the specific molecules to enter the cells it must first bind to a specific receptors on the plasma membrane.
Receptor Mediated Endocytosis
an act of eating or taking in food via the mouth cavity.
Ingestion
involves mechanical and chemical breakdown of large food molecules into soluble or
diffusible molecules that can be absorbed by cells.
digestion
the act of chewing, tearing or mastication of food through the teeth.
Mechanical Digestion
the use of enzymes whereby water is added in hydrolysis to break the
chemical bonds in food.
Chemical Digestion
too large to enter the plasma membrane of the cell so the animal must breakdown these
Macromolecules
where the small molecules, now in the form of building blocks, will be absorbed in the
lining of digestive tract. Animals that eat more than its needs, most of nutrients are converted to fat
for storage.
absorption
whereby undigested food is removed from the digestive tract. (known as defecation or egestion)
elimination
mucin in saliva helps soften the food while the teeth play an important role in
mechanical digestion by masticating food into smaller pieces. Salivary amylase, also begins
chemical digestion of food to form bolus.
Mouth or Oral cavity-
large tube connecting mouth and stomach. known as peristalsis.
esophagus
Muscle layers surrounding the esophagus
cause rhythmic, wavelike contraction.s 5-6 seconds.
peristalsis
j-shaped and covered with muscular layers. Contains gastric juices (HCl and pepsin) pH
1.5-2.5.
stomach
an opening where bolus will enter the stomach, regulate the
passage of food into and out of the stomach. 2-6 hours.
sphicter
a food mixture with gastric juice.
chyme
bile from the liver is added with chyme for further breakdown of fat molecules. It is
made up numerous microvilli to absorb nutrients from the food. It is where absorption of building
blocks take place.
small intestine
the process of transport use of absorbed nutrients
assimilation
absorption of water and mineral salts from undigested food materials. Certain
vitamins, such as vitamin K and two B vitamins are produce, which are needed by our body. 18-24 hours
large intestines
Nutrients that are not digested and absorbed form a solid waste
feces
it is the temporary storage of feces, when it contracts, the feces is expelled through an opening called as anus.
rectum
the plants and other photosynthetic organisms that can produce their own food by converting inorganic
components into organic molecules
autotrophs or self-feeders.
Major component of organic molecules
carbon
oxygen
hydrogen
Component of amino acids, proteins, nucleotides, nucleic acids, chlorophyll,
coenzymes, enzymes
nitrogen
Protein synthesis, operation of stomata
potassium
Component of cell walls, maintenance of membrane structure and permeability,
activates some enzymes
Calcium
Component of ADP and ATP, nucleic acids, phospholipids, several coenzymes
phosphorus
