Learn: Proteins, Enzymes and Biological Roles

Welcome!You've already learned about the role of carbohydrates and lipids in diet and health. Now, let's explore proteins, their structure, how enzymes work, and their biological importance.

What are Proteins?Proteins are large molecules made from building blocks called amino acids. They have many roles, such as providing structure, enabling movement, and speeding up chemical reactions as enzymes.

Amino Acids and PolypeptidesAmino acids link together via peptide bonds to form long chains called polypeptides. When folded, these chains create functional proteins, essential for cells.

Protein StructureProteins have four levels of structure: primary (amino acid sequence), secondary (folding into alpha helices or beta sheets), tertiary (3D shape), and quaternary (multiple polypeptides working together).

What are Enzymes?Enzymes are proteins that act as biological catalysts. They speed up chemical reactions without being used up, ensuring vital processes like respiration happen quickly.

How Do Enzymes Work?Enzymes work via the lock and key model, where the substrate fits into the enzyme's active site. Alternatively, the induced fit model suggests the enzyme changes shape slightly to bind the substrate.

Factors Affecting Enzyme ActivityEnzyme activity is influenced by temperature, pH, and substrate concentration. Extreme conditions can cause enzymes to denature, losing their function.

Biological Importance of Proteins and EnzymesProteins play critical roles, from forming antibodies to transporting oxygen via haemoglobin. Enzymes are essential for processes such as digestion, respiration, and DNA replication.

Review Time!Great work! You've learned about proteins, enzymes, and their biological significance. Let's test your understanding with a few final questions.