Many Proteins Are Enzymes Flashcards
How do enzymes speed up a reaction
Provide an alternate pathway with a lower activation energy
What type of catalyst are enzymes
Biological
Are enzymes proteins
Yes
What is the lock and key model
Shape of the active site doesn’t change when substrate binds
What is the induced fit model
Tertiary structure of the enzyme changes as substrate approaches so active site fits around substrates
What structure proteins are enzymes
Tertiary
What is the key word to always through in for a mark when talking about enzymes
Enzyme substrate complex
Explain in words
Temperature - rate of reaction increasing
Increasing kinetic energy of substrate and enzyme
Increases chance substrate collide with active site
Increase frequency = increase rate of reaction
Explain in words
Temperature - optimum temperature
Maximum number of collisions between active site and enzyme
Explain in words
Temperature - rate of reaction decreases
Enzymes
Higher temperature enzymes vibrating more rapidly
Causes bonds E.g. hydrogen bonds to break
Tertiary structure changes
Substrate no longer fits active site
Denatured
Can a denatured enzyme return to original shape
No
Denaturing is permanent because tertiary structure changed
What does the PH depend on
Concentration of H+ ions
High PH has a …. Concentration of H+
Low PH has a …. Concentration of H+
Low
High
What happens if PH is do low or high on enzyme detailed x3
Interfere with the charges in amino acid
This breaks bonds changing tertiary shape of enzyme
Change active site
What does a competitive inhibitor do
Similar shape to substrate
Bonds to active site and occupies it
Prevents substrate from binding
How to reduce effect of competitive inhibitor
Increase substrate
Does a reaction happen with a competitive inhibitor
No
It’s not the substrate
How do non-competitive inhibitors work
Bind to allosteric site
Tertiary structure of enzyme changes - active site changes no longer complementary to substrate
Less enzyme-substrate complex’s formed
How to limit effect of non-competitive inhibitor
Increasing substrate has NO effect
Can’t do anything
Why is an answer given to a whole number when using a ruler to measure
Reduces uncertainty
Describe how an enzyme can be phosphorylated
Attachment of a phosphate
Released from hydrolysis of ATP
Explain how the active site of an enzyme causes a high rate of reaction.
Lowers activation energy
Induced fit causes active site of enzyme to change
So enzyme-substrate complex causes bonds to break
Formation of enzyme-substrate complex increases rate of reaction
Explain how x2
Lowers activation energy
Due to bending bonds
( because of induced fit model the bonds have to bend to fit around substrate)
Explain how chemical X binding to an enzyme could increase the rate of reaction
( if it is increasing rate of reaction it is NOT an inhibitor)
Binding alters tertiary structure of enzyme
This cause active site to change shape
More Enzyme-substrate complexes formed
