The first page introduces fundamental concepts about cellular metabolism, membrane structure, and enzymatic processes. The content explains how metabolic pathways function through enzyme-controlled reactions and details the importance of membrane structure in cellular processes.

Definition: Metabolism encompasses all chemical reactions occurring within a cell, while a metabolic pathway represents an integrated series of enzyme-controlled reactions.

Highlight: Cell membranes contain three crucial protein types: pores for specific molecular diffusion, pumps for active transport, and enzymes for catalyzing reactions.

Example: The induced fit model demonstrates how enzymes change shape when binding to substrates, improving the efficiency of chemical reactions.

Vocabulary:

• Anabolic reactions: Energy-requiring processes that build larger molecules from smaller ones
• Catabolic reactions: Energy-releasing processes that break down larger molecules into smaller ones
• Activation energy: Initial energy required to start a chemical reaction

Quote: "Enzymes speed up chemical reactions by lowering the activation energy required to form products."

The page also details three types of enzyme inhibition:

1. Competitive inhibition where molecules compete with substrates for active sites
2. Non-competitive inhibition where binding occurs away from the active site
3. Feedback inhibition where end products regulate pathway activity