Exam 2: Lab 7 Digestive Enzymes Flashcards
(27 cards)
What do enzymes do?
Proteins do work
How do enzymes and substrates in solutions find each other?
random molecular collison
how do enzymes and substrates interact?
enzymes + substrates E - S –> E + Product
- enzymes + substrates
- form and irriversibly form an enzyme substrate complex
- would irreversible regenerate the enzyme and create some product
What does it mean for an enzyme to be denatured
3-D shape has been changed
Do denatured enzymes work?
No. Function is highly dependent on its shape.
what can denature an enzyme
- high temperature
- pH
Each enzyme has a temperature and pH optimum. What does this mean?
- Function optimally in that range
- outside of range, it will not function optimally
Function of saliva
- to moisten food
- released by saliva: salivary amylase enzyme
starch
- amylose
- enzyme break it down is amylase
in order to absorb food from small intestine to blood
- must break it all the way down into its monomer subunit
- if not shit it out
once food is swallowed:
pharynx to esophagus to stomach to small intestine to duodenum
mouth has pH of?
stomach has pH of?
- mouth: rough pH of 7 (neutral)
- stomach: rough pH of 2 (acidic)
amylase
- enzyme works well with pH of 7 (neutral)
- gets denatured in stomach pH 2 acidic
- gets released in small intestine by duodenum in pancreatic juice called pancreatic amylase
function of stomach
- temporary storage of food
- no enzymes to breakdown sugar, fat,
enzyme in stomach
- pepsin
pepsin
- activated with low pH
- take big protein and it make it small protein, but not break all the way down to individual amino acids
small intestines
- key to digestive system
- where vast majority of digestion and absorption occurs
- duodenum: 5% of s.i pancreatic juices released
pancreatic juice
- enzymes
- all the enzymes that breakdown food stuff are in juice (pancreatic duct); including pancreatic amylase
breakdown digestion:
- all the lipase (fat) and all the protease (protein) released into small intestine get digestion
- break down all other carbohydrates released in duodenum
IKI result
- K iodine
- results for breakdown of starch (amylose)
- black original
- if positive breakdown: goes lighter
- if negative/no breakdown: black
Benedict’s result for starch breakdown
- look for maltose
- orange positive = there was breakdown of starch
- light blue = no breakdown of starch
5 ml amylose + 5 drops amylase (enzyme)
IKI:
Benedicts:
- IKI = dark brown to copper (positive for IKI/all starch broke down) in 6 min
- Benedict’s result = orange/maltose seen/breakdown of starch +)
5 ml amylose + 1 drop HCl + 5 drops of amylase
IKI:
Benedicts:
- IKI = Black, no change, no breakdown of starch seen, HCl denatured enzyme
- Benedict’s = negative, no maltose seen, HCl denatured enzyme, no digestion occured
5 ml amylose + 2 drop amylase
- IKI = dark purple to copper in 8 min; positive for breakdown; slower due to lower concentration of enzyme
- Benedict’s: positive complete breakdown but slower; saw maltose present