Digestion

Traps in Digestion

• Enzyme misconceptions
  Enzymes are protein catalysts, specific (lock and key), unchanged by reaction. High temperature denatures them; low temperature only slows them. Each has an optimum pH (pepsin ≈ 2, salivary amylase ≈ 7).
• Enzyme-substrate mismatches in digestion
  Amylase: starch → maltose (mouth, duodenum). Pepsin: protein → polypeptides (stomach, acid). Lipase: fats → fatty acids + glycerol (small intestine). Bile emulsifies but is NOT an enzyme.
• Confuses food classes and their functions
  Carbohydrates and fats: energy. Proteins: growth and repair. Vitamins and minerals: protection (e.g. vitamin C → scurvy, iron → anaemia, iodine → goitre). Water and roughage are needed too. A balanced diet has all classes in the right proportions.
• Gives the job of a neighbouring structure or stage
  Learn structures as pairs of 'name → one job' and contrast neighbours: ribosome makes protein, mitochondrion releases energy; cochlea hears, semicircular canals balance. When two options sit in the same organ or process, ask which one does exactly the job in the stem.
• Takes one contributing factor as the whole answer
  Watch for 'only', 'just', 'mainly'. Ask: is this the MAIN reason, or one contributor? If it would need other things to work (plasma proteins need platelets), it is incomplete.