lec 8 pt2 nutrition and digestion Flashcards
living organisms require ____ as nutrients
elements
what are macronutrients?
elements needed in large amounts
which 3 macronutrients make up 93% of our weight?
C, H, O
what are micronutrients? whats an example?
tiny amts necessary for life
eg. vitamins
which element is needed in a small amount to be used to make hormones?
iodine
what are 3 main categories of human dietary requirements?
-carbohydrates
-fats (lipids)
-protien
explain why we need each of the 3 categories of human dietary requirements?
carbs:
-source of energy+carbon
fats:
-concentrated form of energy
-essential fats: required to make certain compounds
protein:
-source of amino acids
-b/c we cant make all AA
what are essential amino acids?
amino acids we MUST obtain from food
how to animals obtain nutrients?
digesting food in order to absorb necessary molecules
one way system that carries food from mouth to anus
digestive system (gut)
what are two roles of saliva?
-moistens food to aid in digestion
-breaks starch–> sugar w/ enzyme amylase
what is the route food takes after leaving the mouth?
esophagus–> stomach–>small intestine–>colon–> anus
once food reaches the stomach, what does the stomach do?
mixes food with acid + stores it
where does food go after the stomach? what happens here?
small intestine
breaks down macromolecules for easy absorption
-small intestine’s epithelial cells absorb
removes additional water and nutrients from food
colon/large intestine
what happens after food passes through the colon?
food becomes feces
expelled thru anus
the animal digestive system involves ______, ________ and waste.
breakdown, absorption
specialized epithelial cells in the stomach secrete…?
HCl- hydrochloric acid
what is the role of hydrochloric acid in the stomach?
-kills most microbes present in food
-breaks down extra-cellular matrix of food
what is the purpose of mucous in the stomach? where is it produced?
-protects epithelial cells from HCl (acid)
-secreted from epithelial cells
the stomach grinds food by….?
peristalsis: muscle contraction
what is peristalsis?
muscle-driven movement of the gut
what are proteases in the stomach? what is an important protease? where are they produced?
enzymes secreted by epithelial cells
Pepsin: breaks down protein
what is the role of epithelial cells in the small intestine?
-secrete digestive enzymes
-absorb nutrients thru active transport