Module 5 PART B Flashcards
extracellular digestion
digestive enzymes secreted into cavity by gland cells
why does extracellular digestion take a long time?
bc digestive enzymes are diluted in fluid
intracellular digestion
endocytosis - cells lining gastrovascular cavity move partially digested food into cell
Membrane food vacuole fuses w/ lysosome to form digestive vacuole & waste is released by exocytosis
crop (in more complex organisms than hydra or jellyfish which only have 1 gut cavity)
storage chamber where food is stored & digested slowly over time. Enlarged portion of the digestive system (in invertebrates & birds) – e.g. in a worm
gizzard
a muscular part of the gut that has grits or stone in it that helps grind the food mechanically. Gizzards are found in birds, earthworms, some fish, & some reptiles
how do lipids enter the cellular respiration pathway?
by first being broken down into glycerol & fatty acids and then entering through beta oxidation
animals cant synthesize the acetyl group so where does it come from & what is it used to synthesize?
comes form food
Acetyl group used to synthesize steroid hormones + amino acids, heme, & other compounds; fatty acids, citrate, etc.
amount of food needed depends on
- metabolic rate (varies w age, reproductive stage, activity)
- body mass & environmental conditions
- types of food
per unit body mass SMALL animals need more/less than larger ones?
MORE as small animals have larger SA:V ratio
carnivorous teeth
greatly enlarged canine teeth for gripping, killing, & tearing their prey - also have incisors
herbivorous teeth
have incisors - mainly have premolars & molars
omnivorous teeth
multipurpose set of teeth
pyloric sphincter (constriction in tube in stomach)
determines how much chyme is allowed into the next section of the digestive system
enzymatic digestion occurs where?
in duodenum
In the duodenum, large lipid droplets are emulsified into smaller micelles and this increases the SA for the lipases to work in an aqueous environment to break down the lipids into monoglycerides and fatty acids
nutrient absorption occurs where?
in jejunum