Metabolism

<aside> 🗣 All chemical reactions take place inside body cells of an organism

1. Catabolism: break down complex molecules into simpler ones
   • breaking down glucose to release energy
2. Anabolism: build up complex molecules from simpler ones
   • making complex organic food molecules from simple inorganic molecules </aside>

Catalyst

• substance that increases the rate of chemical reaction and is not changed by the reaction

Enzymes

• Protein that functions as biological catalysts speeding up chemical reactions in an organism
  1. Proteins in nature
  2. Speed up biochemical reactions
  3. Remains unchanged at the end of the reaction; can be reused
  4. Effective in small quantities
  5. Reversible catalyzed reaction
  6. Highly specified: each enzyme can only catalyze one type of reaction
  7. Affected by temperature/ pH: work efficiently within particular range
     • Extreme temperature/ pH → shape of active sites changed → denaturation
• Enzyme biocatalysts are needed for a reaction
  • Low metabolism inside organisms
  • X catalysts → most reactions would be too slow to allow life to go on

Enzyme-substrate complex

• Substrate: molecule that an enzyme acts on
• Active site: small area where the substrate binds to the enzyme
  • 3D shape which must match the shapes of specific substates for reaction to take place

Enzyme + Substrate anabolic → Enzyme-substrate complex - catabolic → Product + Enzyme

• Lock and key hypothesis: substrate is changed, enzyme remains unchanged

Factors affecting enzyme activity

Temperature

• increasing chance to collide with active site | | 40 °C (Optimum Temperature) | activated | Rapidly increases | | > 40 °C | denatured | Rapidly drops
• bonding within enzymes are broken → shapes of active sites are changed |

<aside> 🗣 Heat-resistance enzymes can still function >80 °C

</aside>

pH

• Most enzymes can only function within narrow range of pH
• Above/ below optimum pH:
  • structure of active sites changed → denaturation