Enzymes Flashcards
What are enzymes?
Proteins that help speed up chemical reactions in our bodies.
(and reduce the amount of energy required)
They are involved only in a specific reaction.
Biological catalysts
What is the molecule on which the enzyme acts on called?
The substrate.
What is the most common suffix for an enzyme’s name?
-ase.
What is an active site?
The location on the enzyme where the substrate binds.
What is it called when an enzyme and a substrate are combined?
An enzyme-substrate complex.
What two functions can enzymes serve?
- Speeding up the breakdown of a substrate into multiple products (Catabolism)
- Speed up the buildup of a substrates into one product (Anabolism)
Which factors does an enzyme require to work to its full capacity?
- Optimal temperature
- Optimal pH
What can a high temperature or an altered pH do to an enzyme?
Permanently change the active site, rendering the enzyme dysfunctional.
(Denature the enzyme)
How can low temperature affect an enzyme?
By slowing collisions between enzymes and substrates
(physics in human biology?????)
Define a denatured enzyme.
When an enzyme is permanently changed, rendering it dysfunctional.
How can an enzyme become denatured?
- Extreme temperatures
- A change in pH
What can a low temperature do to an enzyme?
Render the enzyme inactive, meaning it won’t work to its full capacity.
(This state can be changed back.)
Why are enzymes essential for life?
- Metabolic reactions are too slow to maintain life without them.
- Enzymes reduce the activation energy (energy overhead) of a reaction.
Which two models can be used to describe enzyme action?
- Lock-and-key model
- Induced-fit model
What does the lock-and-key model state?
The shape of an enzyme’s (the key) active site will be complementary to the shape of the substrate (the lock).
What does the induced-fit model state?
When the enzyme-substrate complex is formed, weak bonds are formed that cause the shape of the enzyme to change.
(This creates complementary from non-complementary enzymes/substrates)
List 4 factors that affect enzyme activity.
- pH level
- Temperature
- Enzyme concentration
- Substrate concentration
Which pH level do most enzymes work effectively at?
Neutral (pH 7)
Are enzymes reusable?
Yes.
Can an enzyme have more than one active site?
Yes.
How does temperature change enzyme activity?
- Higher - Increase in activity
- Lower - Decrease in activity
What happens to an enzyme if its pH level is suboptimal?
Its ability to combine with its substrate will be affected.
What will increasing the amount of substrate compared to enzymes do?
Increase the amount of products made until all enzyme molecules are working at capacity.
What will increasing the amount of enzymes compared to substrates do?
Increase the rate of reaction, unless no more enzymes are added.
