Oxygen Dissociation & Haemoglobin
This curve represents haemoglobin’s affinity for oxygen at different partial pressures.
What is the oxygen dissociation curve?
The shift of the oxygen dissociation curve to the right due to high CO₂ is called this.
What is the Bohr shift (Bohr effect)?
This pressure forces plasma out of capillaries at the arterial end.
What is hydrostatic pressure?
Bony fish have this type of circulatory system.
What is single circulation?
Root pressure is generated by the active transport of these substances into the xylem.
What are mineral ions?
The S-shaped curve is explained by this phenomenon.
What is cooperative binding?
High carbon dioxide levels cause haemoglobin’s affinity for oxygen to do this.
What is decrease?
This pressure, caused by plasma proteins, pulls tissue fluid back into capillaries at the venous end.
What is oncotic pressure?
Mammals have this type of circulatory system due to their four-chambered heart.
What is double circulation?
Water enters root hair cells by this process.
What is osmosis?
This term refers to the pressure exerted by a single gas in a mixture.
What is partial pressure?
Most carbon dioxide in the blood is transported in this form.
What are hydrogen carbonate ions (bicarbonate ions)?
Tissue fluid differs from plasma because it lacks these two major components.
What are red blood cells and large plasma proteins?
This structure initiates the heartbeat and is known as the pacemaker.
What is the sinoatrial node?
Water can travel through the cytoplasm of adjacent cells via this pathway.
What is the symplastic pathway?
Foetal haemoglobin differs from adult haemoglobin because it contains these polypeptide chains instead of beta chains.
What are gamma chains?
This enzyme catalyzes the conversion of carbon dioxide and water into carbonic acid.
What is carbonic anhydrase?
Approximately what percentage of tissue fluid returns directly to the blood, and what happens to the rest?
What is about 85% returns to blood and 15% enters lymph ducts as lymph?
These fibers carry the action potential to the apex of the heart, initiating ventricular systole.
What are Purkinje fibers?
These pores connect sieve tube elements and allow sap to flow between cells.
What are sieve plates?
Explain why oxygen transfers from maternal to foetal blood in the placenta.
What is foetal haemoglobin has a higher affinity for oxygen than adult haemoglobin, so oxygen dissociates from maternal haemoglobin and binds to foetal haemoglobin?
Explain why haemoglobin releases oxygen at respiring tissues but binds oxygen in the lungs, referring to partial pressures and the Bohr shift.
What is high CO₂ and low O₂ at tissues reduce haemoglobin affinity (right shift), causing oxygen release; high O₂ and low CO₂ in lungs increase affinity, causing oxygen binding?
Describe two structural adaptations of lymph vessels that ensure unidirectional flow of lymph.
What are thin walls compressed by skeletal muscles and valves preventing backflow?
Explain why the left ventricle has thicker cardiac muscle than the right ventricle.
What is it must generate higher pressure to pump blood around the entire body?
Explain how phloem loading at a source creates hydrostatic pressure that drives translocation to a sink.
What is active transport of sucrose into sieve tubes lowers water potential, water enters by osmosis, building hydrostatic pressure that drives mass flow to sinks?