4.1 Study Guide Flashcards
What is the definition of enzyme?
The largest and most diverse proteins produced by living organisms. They are catalysts.
What is the definition of substrate?
Reactant that binds to enzymes.
What is the definition of active site?
Substrate fits into the enzyme.
What is the definition of activation energy?
The energy required to begin a reaction.
Please explain the relationship between reaction rate and substrate concentration.
The substrate increases, so does the reaction rate. The reaction rate also levels off. All enzymes are at the maximum rate of reaction. More substrate more frequently collide with enzyme.
Please explain the relationship between reaction rate and enzyme concentration.
As the enzyme increases, so does the reaction rate. More enzymes = more collisions with substrate. Substrate becomes limiting factor.
Please explain the relationship between reaction rate and temperature.
- As temp increases, so does the reaction rate.
- Optimum Temp = greatest number of successful collisions. Human enzymes = 35-40 degrees Celsius.
- Heat; increase beyond optimum temp. Denaturation = lose 3D shape (3 degree structure). Cold; decrease temp = molecules move slower. Decrease amount of energy and collisions between enzyme and substrate.
Please explain the relationship between reaction rate and pH.
As pH increases, so does the reaction rate. Adds or removes H+, disrupts 3D shape. Denatures protein. Pepsin (stomach) = pH 2-3. Trypsin (small intestines) = pH 8.
Please compare and contrast inhibition and activation of enzymes.
The activation turns enzymes on, while inhibition turns enzymes off.
Please predict what will happen to enzyme rates when the temperature is increased.
Too high of temps can cause an enzyme to denature and stop working.
Please predict what will happen to enzyme rates when the pH is increased.
This will slow enzyme activity.
What is the reactant that binds to the enzyme?
Substrate.
What is the term for when a substrate fits into an enzyme?
Active site.
