Lab 3 (enzyme action) Bio 1
enzymes importance
accelerate and steer chemical processes in organisms
The active site of an enzyme is (3)
catalytically active region of an enzyme, shaped to fit a specific substrate, destroyed if the shape changes drastically
how do high temps and strong acids affect an enzymes shape
cause gross untwisting and disorganization of the structure which destroys the active site and abolishing the enzymes catalytic power
importance of enzymes configuration
chemically reactive groupings make up the catalytic active region (active site)
ONPG (colorless) + lactase =
galactose and ONP (yellow)
lactose + lactase =
galactose and glucose
2 examples of agents that can alter an enzymes shape
high temperatures, strong acids
How does a spectophotometer help?
if less light goes through the solution there must be lots of ONPG since it means a yellow color which causes more absorbance of light
what is the roles of Na2CO3 in activity 1 and 2
inactivate enzyme
what stops the production of galactose and ONP?
sodium carbonate (Na2CO3)
how can we determine how much enzyme is present in a sample of unknown concentration?
using the relationship between enzyme concentration and ONP production (amount vs activity --> standard curve)
Lactase catalyzes the conversion of
ONPG into galactose and ONP
3 steps of making a blank tube in activity 2 (produce a standard curve of enzyme amount vs activity)
(1) 1 ml of .6 units/ml enzyme solution (2) 3 ml of Na2CO3 and mix (3) 1 ml ONPG and mix
3 steps of making a blank tube in activities 1 and 3(investigate the activity of the enzyme lactase / temperature on enzyme activity )
(1) 1 ml of lactase (2) 3 ml of Na2CO3 and mix (3) 1 ml ONPG and mix
what is lactose
A disaccharide made up of glucose and galactose
Why do we add NaCO3 to our tubes?
To stop enzymatic production of ONP
what is lactase
enzyme that catalyzes the digestion of lactose
Why is ONP useful in this experiment?
it's yellow so we can measure how much ONP is produced by the intensity of yellow in the mixture
what happens when ONPG binds to the lactase active site?
its broken down into galactose and ONP
In this lab, higher enzymatic activity will cause:
more ONP production and higher absorbance
Why is ONPG an ideal substrate for lactase
they are similar in structure so it can readily bind to the lactase active site
what are 3 things modified in the experiments?
time, enzyme concentration, temperature
why is lactase important for lactose
to be used as the glycosidic bonds must be
