Learn: Proteins, Enzymes and Biological Roles

Welcome!You've already learned about the heart, blood vessels, and key molecules like carbohydrates and lipids. Now, we'll explore proteins, how enzymes work, and their essential roles in biological processes. Let's dive in!

What are Proteins?Proteins are large molecules made of amino acids. They perform vital functions like enzyme activity, structural roles, and transport in cells. They're essential for the body to function properly.

Amino Acids and Protein StructureAmino acids are the building blocks of proteins. A protein's structure determines its function. Proteins have four levels of structure: primary (sequence of amino acids), secondary (folding into alpha helices or beta sheets), tertiary (overall 3D shape), and quaternary (multiple polypeptides joined).

Enzymes: Biological CatalystsEnzymes are proteins that speed up chemical reactions without being used up themselves. They lower the activation energy, making reactions occur faster. For example, digestive enzymes help break down food.

How Enzymes WorkEnzymes have an active site, where substrates bind. The substrate fits like a 'key' to the enzyme's 'lock'. This forms an enzyme-substrate complex, leading to the reaction and formation of products.

Factors Affecting Enzyme FunctionEnzyme activity is influenced by temperature, pH, and substrate concentration. Extreme temperatures or pH levels can denature enzymes, changing their shape and preventing them from functioning.

Enzymes in Biological RolesEnzymes play roles in processes like digestion (e.g., amylase breaking down starch) and respiration (e.g., ATP production in mitochondria). Without enzymes, these processes would be too slow for life.

Practical: Investigating Enzyme ActivityOne core practical involves studying how temperature affects enzyme-catalysed reactions. For example, you can measure the rate of starch breakdown by amylase at different temperatures. What do you think happens if the temperature is too high?

Review Time!Great work! You've learned about proteins, enzyme structure, and biological roles. Let's test your understanding with a few questions.