Digestive System Basics and Enzyme Action
Ever wondered how your body turns a sandwich into energy? Your digestive system has two main jobs: breaking food down into small, soluble molecules and absorbing these nutrients into your bloodstream.
Enzymes are the real stars here - they're incredibly picky workers! Each enzyme has a uniquely shaped active site that only fits one specific substrate, like a lock and key. This is why enzymes are so specific - only the right molecule can fit.
The lock and key model explains this perfectly: the substrate locks into the enzyme's active site because they have complementary shapes. The enzyme then breaks the bonds in the substrate, creating products that no longer fit the active site, so they leave and the enzyme can work again.
Quick Tip: Remember that enzymes are reusable - they don't get used up in the reaction, which is why your body doesn't need massive amounts of them!
Different organs produce different enzymes. Amylase (breaks down starch into glucose) comes from your salivary glands, pancreas, and small intestine. Protease (breaks proteins into amino acids) is made in your stomach, pancreas, and small intestine. Lipase (breaks fats into fatty acids and glycerol) is produced by your pancreas and small intestine.
