10.3 Enzymes 🔬
1 – Why enzymes matter
- All the life-giving reactions inside our body (digestion, absorption, energy release) run smoothly at body temperature because of special biocatalysts called enzymes 😊 :contentReference[oaicite:0]{index=0}
- Almost every enzyme is a globular protein, neatly folded so that just the right part (the active site) meets its matching molecule, or substrate.
2 – Key features
| Feature | What it means for you |
|---|---|
| Specificity | Each enzyme fits one reaction and (usually) one substrate, like a lock-and-key 🔑 :contentReference[oaicite:1]{index=1} |
| Naming | Named after the substance they act on (maltase acts on maltose) or the reaction type (oxidoreductase catalyses coupled oxidation-reduction). All names end in -ase. :contentReference[oaicite:2]{index=2} |
| Tiny amounts | A pinch is plenty! Only minute quantities are needed to speed up reactions. :contentReference[oaicite:3]{index=3} |
| Lowering “energy hill” | They slash the activation energy. Example: acid hydrolysis of sucrose needs , but the enzyme sucrase trims it to . ⚡ :contentReference[oaicite:4]{index=4} |
3 – A classic enzyme reaction
The enzyme maltase snaps the disaccharide maltose into two glucose units:
\[ \mathrm{C_{12}H_{22}O_{11} + H_2O \xrightarrow{\text{Maltase}} 2\,C_6H_{12}O_6} \] :contentReference[oaicite:5]{index=5}
4 – Mechanism in a nutshell
The process follows three easy steps:
- Approach: Enzyme (E) and substrate (S) collide under gentle body conditions.
- Fit: They form a short-lived enzyme–substrate complex (ES). Think of the substrate sitting snugly in the enzyme’s active pocket 😊.
- Finish: Bonds reshape, the product (P) departs, and the enzyme emerges unchanged—ready for another round!
Important Concepts for NEET 🔥
- Enzymes are globular proteins that act as highly specific catalysts.
- The -ase naming rule (substrate-based and reaction-based names).
- Role of enzymes in lowering activation energy (numerical values are test-friendly!).
- Example reaction: maltase converting maltose to glucose.
- Basic outline of the enzyme–substrate complex mechanism.
