digestion and blood

• What is the definition of digestion?

  Hydrolysis of large insoluble molecules
• What are the three main types of molecules involved in digestion for AQA biology?

  • Carbohydrates
  • Lipids
  • Proteins
• What are the two types of enzymes involved in carbohydrate digestion?

  Amylases and membrane-bound disaccharidases
• Where is amylase produced?

  In the pancreas and saliva glands
• Where does the digestion of carbohydrates begin?

  In the mouth
• What does amylase hydrolyze carbohydrates into?

  Disaccharides from polysaccharides
• What is the first part of the small intestine where digestion continues?

  Duodenum
• What do sucrase and lactase hydrolyze?

  Sucrose into fructose and glucose
• What are the three key sets of enzymes that hydrolyze proteins?

  Endopeptidases, exopeptidases, dipeptidases
• Where does protein digestion start?

  In the stomach
• What is the role of lipase in lipid digestion?

  Hydrolyzes ester bonds in triglycerides
• Where is lipase produced?

  In the pancreas
• What is the function of bile salts in lipid digestion?

  Emulsify lipids into tiny droplets
• Why is emulsification advantageous for digestion?

  It increases surface area for faster hydrolysis
• How do micelles aid in lipid absorption?

  Deliver fatty acids to epithelial cells
• What structures increase the surface area for absorption in the ileum?

  Villi and microvilli
• How are monosaccharides and amino acids absorbed?

  By co-transport and active transport
• What happens to fatty acids and monoglycerides after entering epithelial cells?

  They are reformed into triglycerides
• What is a chylomicron?

  A triglyceride combined with a protein
• How are chylomicrons released from epithelial cells?

  By exocytosis
• Where do chylomicrons go after being released?

  Into the lacteal or lymph vessel
• How do lipids eventually enter the capillary system?

  Through the lacteal draining into capillaries
• What is the main topic of the video by Mr. Stroke?

  Transport of oxygen by hemoglobin
• What is the function of red blood cells?

  To transport oxygen in the blood
• What type of structure does hemoglobin have?

  Quaternary structure
• How many polypeptide chains does hemoglobin contain?

  Four polypeptide chains
• What is the role of heme groups in hemoglobin?

  They bind oxygen due to iron content
• What is myoglobin's function compared to hemoglobin?

  Stores oxygen at low partial pressures
• What are key phrases related to the oxyhemoglobin dissociation curve?

  • Affinity
  • Saturation
  • Loading (Association)
  • Unloading (Dissociation)
• What does the affinity of hemoglobin refer to?

  Its ability to attract or bind oxygen
• What does saturation mean in the context of hemoglobin?

  Maximum amount of oxygen bound to hemoglobin
• What happens at high partial pressures of oxygen?

  Hemoglobin is almost completely saturated
• Why is it advantageous for hemoglobin to unload oxygen at low partial pressures?

  Oxygen is needed in respiring tissues
• What is cooperative binding in hemoglobin?

  First oxygen binding eases subsequent bindings
• What is the Bohr effect?

  Effect of carbon dioxide on hemoglobin's affinity
• What happens to the oxyhemoglobin curve during the Bohr effect?

  It shifts to the right with high CO2
• What does a rightward shift in the oxyhemoglobin curve indicate?

  Decreased affinity for oxygen
• How does acidity affect hemoglobin's affinity for oxygen?

  Increased acidity decreases affinity
• How does fetal hemoglobin differ from adult hemoglobin?

  Fetal hemoglobin has a higher affinity for oxygen
• Why does fetal hemoglobin need a higher affinity for oxygen?

  To extract oxygen from maternal blood