Enzymes - Types of Enzymes Reviewer

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the term for the complex formed when an enzyme and its substrate bind together?

Enzyme-substrate complex

What type of bonds are predominant in the structural integrity of enzymes, especially in maintaining their shape?

Intramolecular bonds

What is the role of cofactors in enzymatic reactions?

Cofactors assist in catalyzing biological reactions.

Which type of coenzyme is derived from vitamins and works loosely with enzymes?

Coenzymes Signup and view all the answers

What is the state of an enzyme when its cofactor is not attached?

Inactive Signup and view all the answers

What is the site where a non-competitive inhibitor attaches to an enzyme?

Allosteric site Signup and view all the answers

Define the term 'redox' in biochemical reactions.

Reduction-oxidation Signup and view all the answers

What happens to electrons when a molecule is oxidized?

It loses electrons. Signup and view all the answers

In the context of enzymes, what model describes a rigid structure that allows only specific substrates to bind?

Lock and key model Signup and view all the answers

What major event occurs during the cell's oxidation of glucose?

Energy is released. Signup and view all the answers

What type of molecules do NAD + and NADH represent in terms of oxidation and reduction?

NAD + is oxidized, and NADH is reduced. Signup and view all the answers

What role do catalytic groups or residues play in enzyme activity?

They help reposition and orient the substrate. Signup and view all the answers

True or false: Enzymes are consumed during the chemical reaction they catalyze.

False. Signup and view all the answers

What role does the active site of an enzyme play in enzyme-substrate binding?

The active site of an enzyme is where the substrate binds and the reactions take place. Signup and view all the answers

Explain why the shape of an enzyme is more important than its length for enzyme-substrate binding.

The shape of an enzyme determines how well it can accommodate and bind to specific substrates, which is essential for catalytic activity. Signup and view all the answers

What is the function of an oxidoreductase enzyme, and provide an example?

An oxidoreductase enzyme catalyzes redox reactions, transferring electrons between molecules; an example is lactate dehydrogenase. Signup and view all the answers

Define the role of a coenzyme and provide two examples.

A coenzyme assists enzymes in catalyzing reactions, enhancing their activity; examples include Vitamin B12 and NAD+. Signup and view all the answers

Describe the function of lyases and give an example.

Lyases split chemical bonds without using water and often create double bonds by removing groups; an example is isocitrate lyase. Signup and view all the answers

What is the role of coenzymes in enzyme activity?

Coenzymes carry or shuttle chemical groups between enzymes, facilitating biochemical reactions. Signup and view all the answers

Define a holoenzyme.

A holoenzyme is a complete functional enzyme that includes both its protein and non-protein parts. Signup and view all the answers

How does the presence of activators influence enzyme activity?

Activators temporarily bind to the active site, enhancing the positive charge of the enzyme's proteins and increasing its activity. Signup and view all the answers

What must be attached to an apoenzyme for it to function?

A cofactor must be attached to an apoenzyme for it to function. Signup and view all the answers

Name the two models that describe enzyme-substrate interactions.

The two models are the Lock and Key Model and the Induced Fit Model. Signup and view all the answers

What distinguishes competitive inhibitors from non-competitive inhibitors in enzyme activity?

Competitive inhibitors mimic the substrate and block the active site, while non-competitive inhibitors attach elsewhere on the enzyme, altering its shape. Signup and view all the answers

How many digestive enzymes are produced in the human body, and what is their significance?

Twenty-two digestive enzymes are produced, essential for breaking down food and facilitating nutrient absorption. Signup and view all the answers

Explain the nature of specificity in enzymes.

The nature of specificity means that enzymes are highly selective and only catalyze reactions with substrates that fit their unique shape. Signup and view all the answers

Study Notes

Enzymes - Types of Enzymes Reviewer

Enzymes are selective, controlling chemical reactions within cells.
Enzymes are composed of proteins.
Substrate is the molecule that binds to the enzyme.
Enzyme-substrate complex forms when the enzyme and substrate meet.
Products are formed when the enzyme and substrate undergo a reaction.
Enzymes are typically globular in shape.
Enzyme structure involves intramolecular and intermolecular bonds.
Intramolecular bonds are strong bonds within a single molecule.
Intermolecular bonds are weak bonds between separate molecules.
Cofactors (or helper molecules) are non-protein chemical compounds that aid enzymes in biological reactions.
Organic cofactors are prosthetic groups and coenzymes.
Inorganic cofactors are metallic ions.
An enzyme without cofactors is inactive.
Coenzymes are loosely bound to enzymes and can carry or shuttle chemical groups between enzymes.
Coenzymes are derived from vitamins.
Holoenzyme is the complete functional enzyme, containing the apoenzyme and the cofactor.
Apoenzyme is the inactive enzyme without the cofactor.
Prosthetic groups are firmly bound to proteins.
Activation energy is the energy needed to start a chemical reaction.
Enzyme activity is affected by concentration of the enzyme.
Active site is the location where enzymes and substrates bind.
Coenzymes temporarily bind to the active site, enhancing protein charge.
Two models describe enzyme-substrate interaction: Lock and Key, and Induced Fit.
The Lock and Key model (proposed by Emil Fischer in 1894) suggests a precise fit between enzyme and substrate.
The Induced Fit model (proposed by Daniel Koshland in 1958) suggests the active site changes shape to accommodate the substrate.
Inhibitors interfere with enzyme function, hindering enzyme-substrate binding.
Competitive inhibitors mimic substrates, competing for the active site.
Non-competitive inhibitors bind to allosteric sites, changing the enzyme's shape.
Redox reactions involve electron loss or gain. Reduction is gaining electrons, Oxidation is losing electrons.

Enzyme Classification

Oxidoreductases catalyze redox reactions (electron transfer).
Transferases transfer functional groups between molecules.
Hydrolases use water to break chemical bonds.
Lyases remove atoms or groups from substrates without using water.
Isomerases rearrange atoms within a molecule.
Ligases join two molecules, usually using ATP energy.

Enzyme Action Examples

Examples of enzymes (and their types) are given:
- Glucose is a reduced molecule.
- NAD+ is an oxidized molecule.
- NADH is a reduced molecule.
- Oxidation leads to loss of electrons.
- Reduction leads to gain of electrons.
- Energy is released when glucose is oxidized in cells.

Studying That Suits You

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

Description

This quiz covers the essential types of enzymes, their structures, and functions. It explores the role of substrates, the enzyme-substrate complex, and the importance of cofactors. Test your understanding of enzyme activity and composition through focused questions.