chpt 14 : human digestive system Flashcards
(30 cards)
what are the 3 types of nutrients
carbohydrates, proteins, fats
why do we need the digestive system
to break down the food we eat into small soluble molecules that can be absorbed and used by our body
why do different parts of our body need to work together
each part serves a different function, they need to work together to be able to digest food effectively
what does physical digestion do
breaks food down into smaller pieces by crushing, grinding, mixing
what does chemical digestion do
breaks food down into small soluble molecules through the actions of enzymes produced by our body
examples of carbohydrates
starchy vegetables, rice, noodles , potatoes
examples of protein
meat, fish, milk, cheese, eggs, green leafy vegetables
examples of fats
cooking oil, nuts, butter, tuna, salmon, avocado
types of enzymes
carbohydrases, proteases, lipases
what are enzymes
biological catalysts
what does carbohydrases do
break down carbohydrates into simple sugars
what does protease do
break down proteins into amino acids
what does lipases do
break down fats into glycerol and fatty acids
what are enzymes sensitive to
temperature and pH
what happens when enzymes is at
- low temp
- high temp
- low pH
- high pH
low temp - inactive
high temp - denature
low pH - denature
high pH - denature
test for starch (carbohydrates)
when iodine solution is added to starch, it will turn from brown to blue-black colour.
test for protein
when biuret solution is added to protein solution, it will turn from blue to purple/lilac colour.
test for fats
when ethanol is added to oil (fats), a white emulsion is formed.
organs in human digestive system
mouth
salivary gland
gullet
liver
stomach
gallbladder
pancreas
small intestine
large intestine
rectum
anus
mouth
physical digestion :
chemical digestion :
teeth crush and grind food into smaller pieces
saliva contains carbohydrase that digest starch partially
gullet
carbohydrase action continues in the gullet but no digestive juices is produced here
stomach
physical :
chemical :
stomach churns food into smaller pieces
proteins are partially digested by proteases
small intestine
carbohydrates, proteins and fats are fully digested here . digested food is absorbed through the walls of the small intestine and into the bloodstream
large intestine
water, vitamins and mineral salts are absorbed through the walls of the large intestine into the bloodstream
