Section 3: Chapter 7: Mass transport NEED TO DO PLANTS Flashcards
How many oxygen molecules can bind to haemoglobin?
4.
What is haemoglobin made up of?
2 beta polypeptide chains, 2 alpha polypeptide chains and 4 haem groups.
(good picture pg161 of textbook)
As partial pressure of oxygen increases, haemoglobin’s affinity for oxygen ______.
Increases.
What happens to the oxygen attached to haemoglobin if the partial pressure of oxygen decreases?
Oxygen is unloaded/disassociated.
What are the x and y axis on an oxygen dissociation curve?
x - Partial pressure of oxygen.
y - Saturation of haemoglobin with oxygen.
Briefly explain the oxygen disassociation curve.
1) Initally shallow as hard for 1st oxygen to bind.
2) Changes shape after 1st oxygen so 2nd and 3rd bind easier - positive cooperativity.
3) Graph flattens - chance 4th oxygen will bind is low.
What is positive cooperativity? (think haemoglobin)
The 1st oxygen binding to haemoglobin makes it easier for the 2nd and 3rd to bind as Hb’s shape changes.
How is fetal haemoglobin different from adults?
Higher affinity for oxygen as oxygen saturation of blood has decreased by the time it reaches placenta.
What is the Bohr effect?
The greater the concentration of CO2 the more readily haemoglobin releases oxygen.
In the presence of carbon dioxide, the affinity of haemoglobin for oxygen ________.
Decreases.
What does CO2 do to make haemoglobin have a lower affinity of oxygen?
Created slightly acidic conditions, so Hb changes shape and unloads oxygen easier.
What are some common features of circulatory systems? (3 points)
1) Suitable medium - For substances to dissolve in. eg/ blood.
2) Means of moving medium - a pump. eg/ heart.
3) Means of controlling flow. eg/ valves.
Why is a mammals circulatory system described as a closed double circulatory system?
- Blood is confined to vessels.
- Blood is passed through he heart twice.
Which chamber has thicker, more muscular walls, atrium or ventricle?
Ventricle.
What are the 4 main vessels connected to the heart?
Aorta, pulmonary artery, pulmonary vein, vena cava.
What is the aorta connected to and what does it carry?
- Left ventricle.
- oxygenated blood → body.
What is the pulmonary artery connected to and what does it carry?
- Right ventricle.
- Deoxygenated blood → lungs.
What is the pulmonary vein connected to and what does it carry?
- Left atrium.
- Oxygenated blood from the lungs.
What is the vena cava connected to and what does it carry?
- Right ventricle.
- Deoxygenated blood from the body.
What are the 3 stages of the cardiac cycle?
1) Cardiac diastole.
2) Atrial systole.
3) Ventricular systole.
What happens during cardiac diastole? (5 points)
1) Atria and ventricles relax.
2) Heart elastic recoils - lowers pressure.
3) Blood - Pulmonary vein and vena cava → atria.
4) Atrioventricular valves open - blood flows - atrium → ventricles.
5) Semi lunar valves closed.
What happens during atrial systole? (1 point)
Atria contract so all blood goes to ventricles.
What happens during ventricular systole?
1) Ventricles contract - atrioventricular valves close.
2) Semi-lunar valves open.
3) Blood leaves ventricles through aorta and pulmonary artery.
What is the structure of the arteries related to function?
- Thick walls - bc of high blood pressure.
- Elastic tissue - stretch and recoil for smooth blood flow.
- Smooth muscle lined with smooth epithelium - reduce friction, smooth blood flow.
