Learn: Proteins, Enzymes and Biological Roles

Welcome!You've already learned about the heart, blood vessels, and how the cardiovascular system works. Now, let's explore proteins, enzymes, and their biological roles. These are essential for processes like digestion, respiration, and cellular functions!

What are Proteins?Proteins are large molecules made of amino acids. They are crucial for building and repairing tissues, acting as enzymes, and supporting immune responses. Proteins are essential for nearly every function in your body.

Amino Acids and Protein StructureAmino acids are the building blocks of proteins. Proteins have four levels of structure: primary (sequence of amino acids), secondary (folding into shapes like alpha-helices), tertiary (three-dimensional structure), and quaternary (multiple chains working together).

What are Enzymes?Enzymes are proteins that act as biological catalysts. They speed up reactions by lowering the activation energy needed, without being consumed in the process.

How Do Enzymes Work?Enzymes function using their active site, which binds to a specific substrate. This forms the enzyme-substrate complex, leading to a reaction. Enzymes are highly specific and can be affected by factors like temperature, pH, and substrate concentration.

Factors Affecting Enzyme ActivityThree main factors affect enzyme activity: temperature, pH, and substrate concentration. For example, high temperatures can denature the enzyme, while extreme pH levels can alter the active site shape.

Biological Roles of EnzymesEnzymes play vital roles, including breaking down food during digestion (e.g., amylase breaks down starch), facilitating respiration (ATP synthase produces energy), and supporting immune responses (e.g., lysozyme fights bacteria).

Review Time!Great work! You've learned about proteins, their structures, enzymes, and the factors affecting their activity. Let's test your understanding with a few questions.