Summary: Myp Biology

Read the summary and the most important questions on MYP biology

• 1 Balance

  This is a preview. There are 27 more flashcards available for chapter 1
  Show more cards here

• How is glucose supllied in the body?

  Glucose is supplied by the blood to cells throughout the body. The correct si units for measuring the concentration are millimoles per liter (mmol/L).

• Name a range of possible blood glucose concentrations?

  between 0,0 - 1.0 = extreme hypoglycemia with seizures and loss of consciousness
  
  between 2,0 - 3,0 = lowest concentration for normal brain function
  
  between 3,0 - 4,0 = lowest normal concentration after fasting
  
  between 5,0 - 6,0 = average concentration
  
  between 7,0 - 8,0 = highest normal concentration after eating
  
  10 = hyperglycemia with serious health risks of persisting for more than short periods
  
  blood glucose concentration (mmol/L)
  

• Why cant the glucose concentration be kept at a constant level?

  The glucose concentration cannot be kept at a constant level because the entire volume of blood contains only about 5 grams of glucose and body processes can add or remove it rapidly.

• How is the glucose concentration kept between narrow limits?

  To keep blood glucose concentrations between narrow limits, the amount of glucose removed from the blood must be balanced with the amount which is added. This is achieved by hormones. A hormone is a chemical messenger secreted by a gland cell and transported in the blood. The two principal hormones used to control blood glucose concentration are insulin and glucagon. They are both secreted by the cells in the pancreas. Insulin decreases blood glucose concentration whereas glucagon increases it.

• List the process that add glucose to the blood?

  1. Release of glucose produced in liver cells from amino acids or glycerol
  2. Release of glucose produced in liver cells by breaking down glycogen
  3. Absorption of glucose from digested food in the gut

• List the process that removes glucose from blood?

  1. Uptake of glucose by body cells for use in respiration
  2. Uptake of glucose into muscle and liver cells for coversion to glycogen
  3. Uptake of glucose into adipose cells and its conversaion to fats

• Why is a person with diabetes unable to keep their blood glucose concentration in balance?

  A person with diabetes is unable to keep their blood glucose concentratiom in balance, either because the pancreas does not produce insulin (type 1 diabetes) or because their body cells no longer respond to it effectively (type 2 diabetes). The role of insulin is to reduce blood glucose concentration, it therefore tends to rise too high, either recurrently or persistently.

• What concentrations of millimoles per liter are likely to cause a diabetic coma and are life-threatening?

  Concentrations over 30 mmol/L are likely to cause a diabatic coma and are life threathening.

• When is it likely a person has developed diabetes?

  It is likely a person has developed diabetes when there is glucose present in the urine, or blood glucose concentrations are still high two hours after drinking a test solution containg glucose.

• What is the cause of type 1 diabetes and how is it treated?

  Type 1 diabetes is the result of the body's own immune system destroying the insulin-producing cells in the pancreas. It usually develops in children, onset diabetes. Type 1 diabetes is treated by monitoring blood glucose concentration and injecting insulin to prevent it from rising to high.