RG Digestion and Absorption

• why cant large biological molecules cross cell membranes?

  too big too cross cell membranes this means they cannot be absorbed from the gut into the blood
• give examples of large biological molecules?

  starch

  proteins
• what happens to the large molecules during digestion?

  they are broken down into smaller molecules which can move across cell membranes

  • = they can be easily absorbed from the gut into the blood , to be transported around the body for use by the body cells
• What are most large biological molecules?

  polymers
• what can happen to polymers ?

  polymers can be broken down into smallermolecules/monomers using hydrolysis reactions
• what do hydrolysis reactions do?

  break bonds by adding water
• what happens during hydrolysis?

  • carbs are broken down into disaccharides and then monosaccharides
  • fats are broken down into fatty acids and monoglycerides
  • proteins are broken down into amino acids
• what monosaccharides is sucrose made from?

  glucose fructose
• what monosaccharides is lactose made from?

  glucose galactose
• what monosaccharides is maltose made from?

  GLUCOSE GLUCOSE