Understanding Enzymes and Their Functions

What is the function of enzymes?

What is the area on an enzyme that binds to the substrate molecule called?

What is the name for the molecule that an enzyme catalyzes reactions for?

Each enzyme is specific to a particular substrate.

What is the name of the complex formed when an enzyme binds to its substrate?

What are the two models that describe the interaction between an enzyme and its substrate?

The Induced-Fit Model states that the active site changes shape slightly to accommodate the substrate, strengthening the bond.

What is the function of the catalytic site?

What is the function of the binding site?

Which of the following is NOT an example of an enzyme?

Which enzyme breaks down lactose?

What are the four levels of protein structure?

Secondary structure refers to the sequence of amino acids in a polypeptide chain.

How do enzymes lower the activation energy required for a reaction?

What is the difference between the catalytic site and the binding site?

All enzymes end with the suffix '-ase'.

Enzymes

Biomolecules speeding up chemical reactions in cells.
Function via catalysis.
Many enzymes end with the suffix "-ase".

Active Site

Region on an enzyme recognizing and binding the substrate.

Substrate

Molecule on which an enzyme catalyzes a reaction.
Each enzyme is specific to a particular substrate.

Enzyme-Substrate Complex

Formed when an enzyme binds to its substrate.

Lock-and-Key Model

Active site and substrate have a precise fit, like a lock and key.

Induced-Fit Model

Active site changes shape slightly to accommodate the substrate, enhancing bonding.

Catalytic Site

Amino acid residues within the active site directly catalyzing the reaction.

Binding Site

Amino acid residues binding and orienting the substrate.

Examples of Enzymes

Amylase: Digests starch in saliva.
Trypsin: Breaks down proteins in the small intestine.
Helicase: Unwinds DNA during replication.
Lactase: Breaks down lactose (sugar).

Functions of Enzymes in the Body

Digestion: Amylase, trypsin, pepsin, lactase, etc.
Cell Division: Cyclin-dependent kinases (Cdks).
Nervous Function: Acetylcholinesterase.
DNA Replication: Helicase, DNA polymerase, etc.

Catalysis and Activation Energy

Enzymes lower the activation energy needed for a reaction.
This happens by modifying reactants to a transition state.

Protein Structure

Primary Structure

Sequence of amino acids in a polypeptide chain.

Secondary Structure

Folding pattern of the polypeptide chain (e.g., alpha helix, beta pleated sheet).

Tertiary Structure

Overall three-dimensional shape of a single polypeptide chain.

Quaternary Structure

Arrangement of multiple polypeptide subunits in a protein.

Additional Information

Not all enzymes end with the suffix "-ase".
Exceptions include pepsin, pepsinogen, trypsin, and rennin.
Difference between catalytic and binding sites: The catalytic site directly catalyzes the reaction, while the binding site is responsible for binding and orienting the substrate.

This quiz explores the essential concepts related to enzymes, including their function, structure, and interaction with substrates. Key models like the Lock-and-Key and Induced-Fit are discussed, along with examples of specific enzymes and their roles in biochemical reactions.