Rate Of Reaction Flashcards
What is the energy needed to make a reaction happen called?
Activation energy
What is the short hand for activation enrgy?
Ea
What effect to enzymes have on Ea?
Enzymes work by reducing the Ea.
Ea lowered-means it is easier for reaction to happen
What are the 2 possible effects of a rise in temperature?
Increases kinetic energy.
Either more enzyme-substrate complexes or
Denaturation
How does an increase in temperature increase enzyme-substrate complexes?
Molecukes have more kinetic energy meaning enzymes and substrates are more likely to collide
How does an increase in temperature dentaure an enzyme?
Molecules vibrate more which can break bonds and alter a molecules structure.
What happens at low temperatures?
There is low kinetic energy. Few enzyme-substrate complexes being formed so rate of reaction is slow. q
Are enzymes denatured at low temperatures?
No
Just low energy
What is an enzymes optimum temperature?
Where the rate of reaction is at its highest. Enough energy to increase enzyme-substrate complex formation but not enough to dentaure enzymes.
What is the optimum temperature for most enzymes in the body?
37°C
What happens when pH is changed away from the norm?
Bonds start to change.
Active site changes shape.
Too far from the norm the enzyme is denatured.
What is the graph of pH and reaction rate?
Bell shape over optimum pH
What does pH effect on an enzyme?
Charges on R groups. Hydrogen and Ionic bonds between R groups.
What is the optimum pH for stomach enzymes?
pH of about 2
What haopnes as substrate concentration increases?
Rate of reaction increases.
Why does the rate of reaction increase with substrate concentration increase?
Extra substrate means more likely to collide with enzyme. Forms enzyme-substrate complex
What does the graph of substrate concentration and rate of reaction look like?
Steady inacrease then flatten out.
Enzymes working at optimum rate.
Why can an enzyme never reach its true optimum?
Due to the time taken for products to leave an active site and a new substrate to enter.
What happens when enzyme concentration is increased?
Rate of reaction increases.
What is a limiting factor?
A factor limiting the rate of the process.
Where increasing the level of that factor increases the rste but other factors have no effect.
What are allosteric activators?
Conpunds that can activate enzymes to make he active site change shape so the substrate can now fit.
