Lab Report
Research Question How will the addition of different pH buffers to amylase affect the rate of starch digestion measured using starch and iodine?
Introduction Amylase is an enzyme found in human saliva and pancreas. It is the digestive enzyme that is needed to breakdown starch molecules. Amylase must be kept at certain conditions to function at its optimum level. This experiment will explore the effect of pH (1, 4, 7, 10, and 14) on the function of amylase by using starch and iodine.
Usually iodine has a orange-yellow color, but iodine and starch react to produce a dark blueblack color, so iodine may be used as an indicator to show the rate at which starch is broken down.1 This occurs when polyiodide chains are formed from starch and iodine. However, as starch is hydrolyzed into smaller carbohydrate units, the blue-black color does not appear. Therefore, using this iodine test, the effects of pH on the function of amylase can be determined by the time it takes (if at all) for the iodine to remain its orange-yellow color.2
Hypothesis Enzymes must be kept at certain conditions to function at its optimum level. Indeed, factors that may cause the enzyme to denature are: pH, temperature, and salt concentrations. When an enzyme is denatured, it can no longer bind to the active site, and therefore cannot carry out its functions. Therefore, adding pH buffer to amylase will affect the enzyme’s function upon its addition to starch, which can be indicated by the iodine test. In fact, if the enzyme is denatured by the pH buffer, the iodine will turn blue-black when starch and enzyme solutions are added because the enzyme didn’t digest the starch. However, if the optimum pH is added
1
" H o w A m y l a s e Wo r k s . " L e s s o n S n i p s . L e s s o n S n i p s , n . d . We b . 1 0 J a n 2 0 1 1 . < h t t p : / / w w w. l e s s o n s n i p s . c o m / d o c s / p d f / a m y l a s e w o r k . p d f > . 2 Senese, Fred. "How does starch indicate iodine?."General
Introduction Amylase is an enzyme found in human saliva and pancreas. It is the digestive enzyme that is needed to breakdown starch molecules. Amylase must be kept at certain conditions to function at its optimum level. This experiment will explore the effect of pH (1, 4, 7, 10, and 14) on the function of amylase by using starch and iodine.
Usually iodine has a orange-yellow color, but iodine and starch react to produce a dark blueblack color, so iodine may be used as an indicator to show the rate at which starch is broken down.1 This occurs when polyiodide chains are formed from starch and iodine. However, as starch is hydrolyzed into smaller carbohydrate units, the blue-black color does not appear. Therefore, using this iodine test, the effects of pH on the function of amylase can be determined by the time it takes (if at all) for the iodine to remain its orange-yellow color.2
Hypothesis Enzymes must be kept at certain conditions to function at its optimum level. Indeed, factors that may cause the enzyme to denature are: pH, temperature, and salt concentrations. When an enzyme is denatured, it can no longer bind to the active site, and therefore cannot carry out its functions. Therefore, adding pH buffer to amylase will affect the enzyme’s function upon its addition to starch, which can be indicated by the iodine test. In fact, if the enzyme is denatured by the pH buffer, the iodine will turn blue-black when starch and enzyme solutions are added because the enzyme didn’t digest the starch. However, if the optimum pH is added
1
" H o w A m y l a s e Wo r k s . " L e s s o n S n i p s . L e s s o n S n i p s , n . d . We b . 1 0 J a n 2 0 1 1 . < h t t p : / / w w w. l e s s o n s n i p s . c o m / d o c s / p d f / a m y l a s e w o r k . p d f > . 2 Senese, Fred. "How does starch indicate iodine?."General