Organisms and exchange

• What is Digestion?

  Where large insoluble molecules are hydrolysed into smaller molecules that can be absorbed across cell membranes.
• Enzymes that are used to hydrolyse carbohydrates are

  amylase and membrane bound disaccharide’s
• Where is Amylase produced

  In the pancreas and salivary glands
• Digestion begins where

  In the the mouth, continues in the duodenum and completed in the ilium
• What is Endopeptidase

  When peptide bonds are hydrolysed within the amino acids in the middle of polymer chain
• What is Exopeptidase

  Where peptide bonds are hydrolysed between amino acids at the end of the polymer chain
• What is Membrane bound dipeptidase?

  When Peptide bonds between 2 amino Acids are hydrolysed
• Where does the digestion of Proteins occur

  In the stomach, into the duodenum and into the ielum
• What does Lipase do?

  Hydrolyse Ester bonds in the triglycerides to form Monoglycerides and fatty acids
• What do Bile salts do?

  Produced in the liver emulsify lipids to form michelles
• Physical Digestion Lipids

  Emulsification of lipids covered in bile salts making an emulsion make small droplets of lipids increasing surface area which enables faster hydrolysis action by lipase
• What Is the point of valves

  Prevent the backwards flow of the blood creating one way outlets of blood
• What is between the Atrium + the ventricles (that prevent backfloe of blood)

  The left Atrioventricular (bicuspid) valve

  The Right Atrioventricular (tricuspid) valve
• what is the aorta

  carries oxygenated blood from left ventricle into all parts of the body Excl lungs
• Pulmonary Artery

  carries deoxygenated blood from the right atrium into to the lungs where the oxygen is replenished and carbon dioxide is removed
• Pulmonary vein

  Carries oxygenated blood from the lungs to the heart & Connected to left Atrium
• Suggest why it is important to prevent mixing of the blood in the two sides of the heart?

  The mixing of Oxygenated and Deoxygenated would result In partially oxygenated blood reaching the tissues& Lungs, less oxygen and there would be reduced diffusion as the gradient will decrease limiting rate of oxygen uptake
• Cardiac muscles

  Have thick myogenic walls which will contract&Relax without hormonal stimulation and never fatigues
• What supplies the cardiac muscles with blood

  The Coronary arteries supply it with oxygenated blood (branching off the aorta)
• If the coronary arteries are blocked what happens?

  Cardiac muscles can’t receive oxygen and won’t respire and cells will die resulting in myocardial infarction (A heart attack)
• What is the structure of the Atria in the 4 chambers

  Has Thinner walls because it doesn’t need to contract for blood and stretch when blood enters
• What is the structure of the ventricles

  Thickets walls to enable contracting and a high blood pressure to make blood flow to more parts of the body eg lungs and rest of body
• What is the Vena Cava

  Brings deoxygenated blood from the body to the right atrium
• What happens during diastole

  The Atria and the Ventricular muscles are relaxed, this is when blood will enter the atria via vena cava and pulmonary vein.
• What happens during Atrial systole ?

  the Atria muscles contract, increasing the pressure and increases blood flow. causing atrioventricular valves to open and blood flows into the Ventricles
• What happens during Ventricular Systole?

  After a short delay the ventricles fill with blood and walls contract increasing pressure. causing atrioventricular valves close and the semi lunar valves to open
• What is the movement of Ventricles in Ventricular systole?

  Ventricles have thick muscular walls , meaning they can contract creating a high blood pressure, the left ventricular is more thick as it has to be pump blood to the body and the right thinner as it pushes to the lungs
• What happens to the remaining tissue fluid?

  It is absorbed into lymphatic system and eventually drains back into bloodstream near heart.
• What does the lymph system contain

  Lymph nodes which filter out bacteria and foreign material from fluid with the help of lymphocytes (Which destroy pathogens as part of immune defence)
• What is the stuff that remains in the capillaries?

  Red Blood Cells, Platelets and Large proteins
• What is forced out the capillaries?

  Water Glucose amino acids fatty acids ions and oxygen also known as (Ultrafiltration)
• Circulatory system of Mammal 


  Please look at this

  
• What is affinity in oxygen?

  how strongly oxygen is bound to globin
• What is saturation in Oxygen?

  How much oxygen is bound to haemoglobin
• What is association/dissociation?

  how oxygen loads and unloads, how it attaches and how it gets dropped of the oxygen
• What does a) low temperature and b) high temperature do to the affinity of oxygen

  • left shift -A
  • right shift -B
• How does A) alkaline and B) acidic affect the affinity

  if ph goes higher (ALKALINE) it shifts to the left

  if ph goes lower (acidic) it shifts to the right
• what is the difference between fetal haemoglobin and adult haemoglobin?

  Fetal shifts to the left, meaning it has a higher affinity and even though its at the same partial pressure the saturation levels are also higher in fetal
• Why is it an advantage that fetal haemoglobin has a higher affinity for oxygen even at the same partial pressure as adult?

  Maternal-fetal oxygen transfer. Easier to pick up and load from mother, in order to grab adults oxygen
• Llamas live at high altitudes where there is lower partial pressure of oxygen, what is their affinity?

  Its higher so shifts to the left