Lecture 2 - Nutrition Flashcards
interaction of nutrients and other substances in food in relation to maintenance, growth, reproduction, and health
nutrition
- known as producers
- able to make their own food from raw materials and energy
Autotrophs
Examples of autotrophs
- plants
- algae
- some types of bacteria
- known as consumers
- consume producers or other consumers.
heterotrophs
Example of heterotrophs
- animals
- fungi
- most bacteria
acquisition of ingestion of food
feeding
process of breaking down complex compounds into simpler ones
digestion
Different types of heterotrophic nutrition
- Saprotrophic nutrition
- Parasitic nutrition
- Holozoic nutrition
feeds on dead plants, dead and decaying animal bodies
saprotrophic nutrition
example of saprotrophs
- yeast
- mushroom
feeds on the nutrients of another living organism
parasitic nutrition
example of parasites
- tapeworm
- lice
condition in which an individual host receives more parasitoids of the same species than can develop to maturity, regardless of whether the parasitoids (eggs or larvae) were distributed by a single female or by several females.
superparasitism
organism that has young that develop on or within another organism (the host), eventually killing it
parasitoid
consumes a variety of organic material, which then undergoes a series of metabolic processes such as digestion, absorption, and assimilation
holozoic nutrition
example of holozoic organisms
- human beings
- amoeba
Three major categories feeding type on the basis of size and type of food utilized of invertebrates
- Microphagy
- Macrophagy
- Fluid or Soft Tissue Feeding
what is the basis of feeding in invertebrates
size and type of food
Feeding on items that are very much smaller than the organism consuming them
microphagy
what do microphagous organisms use to capture food
- cilia
- setae
Different types of ciliary feeders
- suspension feeders
- filter feeders
- organisms that capture food particles suspended in the water column
- don’t have the filtering mechanism
- passive
suspension feeders
example of suspension feeders
- barnacles
- anemones
what do barnacles use to capture food
cirri
- slender tendril or hairlike filament
- long, thin structure in an animal similar to a tentacle but generally lacking the tentacle’s strength, flexibility, thickness, and sensitivity.
cirri
what do anemones use to capture food
tentacles
- organisms with specialized filtration apparatus to strain food particles from the water
- actively pump water through their filters
- active strategy
filter feeders
example of filter feeders
- baleen whales
- clam shells
- sponges
what do baleen whales use to capture food
baleen plates
what do clam shells use to capture food
gills
what do sponges use to capture food
choanocytes
what are the food acquired in microphagy
- organic matter
- plankton
- detritus
- feed on large masses of food
- active predators
macrophagy
example of macrophagous animals
- octopus
- mollusks
- consume liquid food or nutrients directly from their source
- typically have specialized mouthparts or adaptations that allow them to pierce or suck fluids from plants, animals, or other sources
fluid or soft tissue feeding
Different mouthparts of fluid or soft tissue feeders
- proboscises
- stylets
- piercing-sucking mouthparts
elongated sucking mouthpart that is typically tubular and flexible
proboscises
small style, especially a piercing mouthpart of an insect
stylets
pierce food items to enable sucking of internal fluids
piercing-sucking mouthparts
example of animals that have proboscises
butterfly
example of animals that have stylets
- aphids
- leafhoppers
example of animals that have piercing-sucking mouthparts
mosquitoes
animals that feed on blood
hematophagous
inject digestive enzymes into the prey to liquify internal tissues of the prey
spiders
breaking of large and complex molecules of the food, after which, they become absorbable and available for use in the ody
digestion
Different types of digestion
- mechanical digestion
- chemical digestion
- purely physical process that does not change the chemical nature of the food
- it makes the food smaller to increase both surface area and mobility
Mechanical digestion
- process where complex molecules like proteins, fats, and carbohydrates are broken down into smaller pieces that your body can use
- requires special proteins called enzymes
Chemical digestion
Different types of digestion based on where it happens
- Intracellular digestion
- Extracellular digestion
refers to nutrient processing and absorption that occurs inside of cells within special structures known as lysosomes
Intracellular digestion
in intracellular digestion, what captures the food
vacuole
example of organisms that have intracellular digestion
- protozoans
- poriferans
represents the process of food digestion and nutrient absorption that occurs outside of the cell.
extracellular digestion
Phases of Digestion
- cephalic phase
- gastric phase
- intestinal phase
- hormones of the digestive system
- occurs before food enters the stomach, especially while it is being eaten
- gastric secretion is initiated by the sight, smell, thought or taste of food.
- Neurological signals originate from the cerebral cortex and in the appetite centers of the amygdala and hypothalamus.
- enhanced secretory activity is a conditioned reflex.
- This phase of secretion normally accounts for about 20 percent of the gastric secretion associated with eating a meal
cephalic phase
second phase of digestion that follows mastication (chewing) and takes place in the stomach
gastric phase
Three chemicals that stimulate gastric secretion
- Acetylcholine (ACh)
- Histamine
- Gastrin
occurs in the duodenum as a response to the arriving chyme, and it moderates gastric activity via hormones and nervous reflexes
intestinal phase
thick, semifluid mass of partly digested food that is passed from the stomach to the duodenum.
chyme
Five major hormones that aid and regulate the digestive system
- gastrin (stomach)
- secretin (small intestine)
- cholecytokinin (small intestine)
- gastric inhibitory peptide (small intestine)
- motilin (small intestine)
- tiny finger-like projections found on the surface of certain cells
- increase the surface area of the cell’s apical surface, resulting in more effective absorption or secretion of substances
Microvilli
