Enzymes Flashcards 12/15

Questions and Answers

What is the amount of energy required to get a chemical reaction started called?

activation energy

Why do you need energy to get a chemical reaction started?

Activation energy is needed to break the bonds of reactant molecules.

How does activation energy serve as a barrier to chemical reactions?

It serves as a barrier to the chemical reaction occurring.

How do enzymes affect activation energy?

Enzymes decrease the required amount of activation energy. Signup and view all the answers

What is crucial to an enzyme's function?

The three-dimensional structure of enzymes. Signup and view all the answers

What are enzymes?

Proteins that catalyze reactions in cells. Signup and view all the answers

How are enzymes named?

They usually end with -ase. Signup and view all the answers

What is a substrate?

The reactant molecule(s) that an enzyme acts on. Signup and view all the answers

What is the active site?

The region of the enzyme that binds with the substrate. Signup and view all the answers

What is an enzyme-substrate complex?

The enzyme and the substrate combined. Signup and view all the answers

What is an allosteric site?

A region on the enzyme that a regulatory molecule can bind to. Signup and view all the answers

Are enzymes very specific to a specific substrate?

True Signup and view all the answers

What does the enzyme accomplish by binding to substrate?

It changes the enzyme's shape slightly, putting strain on the bonds of the reactant molecules. Signup and view all the answers

Are enzymes reusable and do enzymes change in chemical reactions?

False Signup and view all the answers

What does the lock and key model explain?

The specificity of enzymes. Signup and view all the answers

What does the induced fit model explain?

How enzymes weaken bonds of reactants and decrease activation energy needed. Signup and view all the answers

How does increasing the amount of substrate or enzyme affect the rate of a chemical reaction?

Adding substrates does not speed up the reaction if all enzymes are used, but adding more enzymes will speed it up. Signup and view all the answers

What is the effect of hot temperatures on enzymes?

It speeds up chemical reactions until enzymes are denatured. Signup and view all the answers

What is the effect of cold temperatures on enzymes?

Cold temperatures decrease the rate of reaction. Signup and view all the answers

What is the effect of pH on enzymes?

Decreasing or increasing pH can denature an enzyme. Signup and view all the answers

Study Notes

Activation Energy

Activation energy is the energy necessary to initiate a chemical reaction.
It is needed to break the bonds of reactant molecules, enabling them to rearrange and form new bonds.

Role of Activation Energy

Activation energy acts as a barrier that prevents chemical reactions from occurring unless sufficient energy is available.
Chemical reactions in cells may proceed very slowly without adequate activation energy.

Enzymes and Activation Energy

Enzymes are biological catalysts that lower activation energy, facilitating and accelerating reactions without altering the total energy released.

Structure and Function of Enzymes

The three-dimensional structure of enzymes is crucial for their function.
Enzymes are proteins that catalyze reactions essential for life in cells.

Enzyme Naming

Enzymes typically have names that end with "-ase," often derived from their substrate (e.g., maltase breaks down maltose).

Substrate and Active Site

The substrate is the reactant molecule that enzymes act on, fitting into the active site of the enzyme.
The active site is the specific region on the enzyme that binds to the substrate.

Enzyme-Substrate Complex

The enzyme-substrate complex forms when an enzyme binds with its substrate.

Allosteric Site

The allosteric site is a distinct region on the enzyme where regulatory molecules can bind, altering the enzyme's shape and preventing substrate binding to the active site.

Enzyme Specificity

Enzymes are highly specific and bind only to particular substrates, forming an enzyme-substrate complex.

Mechanism of Action

Binding of the substrate to the active site alters the enzyme's shape, putting strain on bonds of reactant molecules and reducing energy needed to break them.

Reusability of Enzymes

Enzymes can be reused after a reaction and remain unchanged in chemical composition.

Models of Enzyme Action

The lock and key model illustrates enzyme specificity by comparing the substrate to a key that fits a specific lock (active site).
The induced fit model describes how enzyme shape adapts to the substrate, enhancing the weakening of bonds and reducing activation energy.

Effect of Substrate and Enzyme Concentration

Increasing substrate concentration can speed up reaction rates until all enzymes are occupied. Additional enzymes, however, will enhance reaction rates.

Temperature Effects on Enzymes

Higher temperatures increase molecular movement and collision likelihood, enhancing reaction rates until enzymes denature, rendering them ineffective.
Cold temperatures slow down reaction rates without denaturing enzymes; normal activity resumes when temperatures rise.

pH Effects on Enzymes

Extreme changes in pH can denature enzymes, affecting their functionality and catalytic activity.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on enzymes and activation energy with this set of flashcards. Understand the importance of activation energy in chemical reactions and how living organisms obtain the necessary energy. Perfect for students studying biochemistry.