Enzyme Kinetics and Factors that affects enzymatic reactions Flashcards
Enzymes catalyze physiologic reactions by __ the activation energy level that the reactants must reach
Lowering
The greater the activation energy level required, the __ the reaction to proceed
Longer
The lower the activation energy, the __ formation of products
Faster
Enzymes combined with only one substrate and catalyze only one corresponding reaction
Absolute specificity
Enzymes combined with all substrate containing all chemical group
Group Specificity
Enzyme that will combine with a specific
chemical bond present
Bond specificity
Enzymes combined with only one optical isomer
Stereoisomeric specificity
The greater the substrate present, the more/higher enzymatic reactions/higher rate of enzyme activity can occur
Substrate concentration
When the substrate concentration reached a maximal value, enzymes are exhausted already, addition of substrate could no longer result in increased rate of reaction. This is called
Saturation kinetics
Reaction rate is proportional to the substrate concentration (increasing) thus, (greater substrate, more enzymatic reaction) but no reaction in maximal value
First order Kinetics
Only a fixed number of substrate concentration (in excess) is converted to product per second. This is usually used in the laboratory.
Zero order Kinetics
The higher the enzyme concentration, the faster is the reaction because the more enzymes present, the greater is the binding site with a substrate which is converted into a product.
Enzyme concentration
Most physiologic reactions occur in what pH?
7.0 to 8.0 (near to plasma pH)
What will happen if the pH is too acidic or basic?
It will denature the protein of enzyme
Exemption to this because they can react in extremely high or low pH
Phosphatases
can react to pH 3.0- 5.0
Acid phosphatase
can react to pH 9.0
Alkaline phosphatase
Has a vital role in enzyme reaction.
Temperature
Assay temperature should be constant within
+/- 0.1 degC
Incubation period is slow
Room temp (25-30degC)
Incubation period is faster
Warm or faster temp (37degC)
Optimum temperature for enzymatic activity
37degC
Start of significant decrease in enzyme activity (start of protein denaturation of their tertiary structure)
40-50degC
Most enzymes are denatured *significant denaturation
56degC
Enzyme is inactivated
60-65degC
For every 10degC increase in temp, there will be a two-fold increase in enzyme activity.
Temperature Quotient (Q10)
Most enzymes are thermolabile except to placental alkaphos specifically
Regan Alkaphos (Thermostable)
Agents that could interfere with enzyme-substrate reaction, they could prevent substrate conversion
Inhibitors
Competes with the substrate to the active site of the enzyme (can physically bind to the active site of enzyme).
Competitive inhibitor
This inhibitor can affect the velocity of enzyme reaction
Competitive inhibitor
T/F: . As you add more competitive inhibitors, it will decrease or slow down the activity.
TRUE
Does not compete with the substrate to the active site of enzyme
Noncompetitive inhibitor
Noncompetitive inhibitor bind to other site of enzyme which is the
Allosteric site
Bind with the enzyme- substrate complex
Uncompetitive Inhibitor
General temperature for enzyme for storage
Freezer temp (-20degC or colder)
If multiple freeze-thawing is done, what will happen?
It could damage and destroy enzymes in the serum.
The ideal temp for storage of substrate and coenzyme (reagents)
Ref temp (2-8degC)
The ideal temp for storage of serum (Target: LDH)
Room temp (20-24 degC)
Hemolysis can falsely __ the serum-enzyme concentration
Elevate
