6 Markers

• In a person with CF, cells lining the digestive system create too much mucus

  The mucus can block duct leading from pancreas to small intestine and block tubes leading to the alveoli in the lungs...Explain why children with CF grow more slowly than children without

  • Less enzymes in the small intestines
  • enzymes breakdown less food so less nutrients are absorbed
  • less glucose enters bloodstream for respiration which releases energy for growth
  • There are also fewer amino acids which are used for growth
  • Tubes leading to alevoli being blocked means less oxygen carried to body cells which means less respiration
  • Less respiration means less energy needed for growth
• Describe how a student could test cows milk for protein and different carbohydrates

  • Test for protein involves biurette reagent
  • Add 3 drops of the reagent to 10cm of cows milk
  • Positive test = colour change from blue to purple
  • Test for starch is iodine;
  • Add 3 drops of iodine to the cows milk
  • Positive test= orange to blacky blue
  • Test for sugars is benedicts;
  • Add 3 drops of benedicts reagent to cows milk
  • Heat solution in a water bath over 60 degreed
  • Positive test= colour change from blue to yellow