Topic 3: Mass Transport In Animals Flashcards
Describe the structure haemoglobin
Haemoglobin is a protein with a quaternary structure. It has four haem groups, containing iron
Describe the oxyhaemoglobin dissociation curve
Oxygen is loaded in regions with high partial pressure of oxygen (eg alveoli) and is unloaded in regions of low partial pressure of oxygen (eg respiring tissues) This is shown on the oxyhaemoglobin dissociation curve
Explain cooperative binding
The affinity haemoglobin has for oxygen changed depending on how many oxygen molecules are already associated with it. Haemoglobin can associate with four oxygen molecules and as each molecule binds, the shape of the haemoglobin changes making the binding of further oxygen molecules easier.
Therefore, in areas with high partial pressure of oxygen, mean meaning a high concentration, the affinity of haemoglobin for oxygen is high and it loads more oxygen.
In humans, the aveoli have a high partial pressure of oxygen and therefore haemoglobin will readily load with oxygen here.
What is Bohr effect?
The Bohr effect is when a high CO2 concentration causes the oxyhaemoglobin curve ti shift to the right. The affinity for oxygen decreases because acidic carbon dioxide changes the shape of haemoglobin slightly. When co2 dissolves in liquid carbonic acid forms and this decrease in pH changes the shape of haemoglobin slightly, which is why the affinity for oxygen decreases. In respiring tissues, this is advantageous, as the haemoglobin delivers the oxygen to the site of respiring cells so that aerobic respiration can continue
describe and explain how llama
haemoglobin is adapted to their environment:
Llamas live at high altitudes where the atmospheric pressure is low and so there is a lower partial pressure of oxygen. Llamas have a type of haemoglobin with a higher affinity of oxygen so that despite the low partial pressure of oxygen, it is still loaded onto haemoglobin. The curve shifted to the left, indicating a higher affinity even at low pp Oxygen
Use the graph to describe and explain how dove haemoglobin is adapted to their environment:
Animals with faster metabolisms, like a fast-moving dove, need more oxygen for respiration to provide energy for contracting muscles.
Therefore their haemoglobin has a lower affinity so that it can readily unload oxygen, which is why the curve has shifted to the right.
What type of circulatory system do mammals have?
In mammals, their circulatory system is a closed, double circulatory system.
What is meant by:
Closed -the blood remains within the blood vessels.
Double - the blood passes through the heart twice in each circuit. There is one circuit that delivers blood to the lungs and another circuit that delivers blood to the rest of the body.
Explain why mammals require a double circulatory system:
To manage the pressure of blood flow. The blood flows through the lungs at a lower pressure. This prevents damage to the capillaries in the alveoli and also reduces the speed at which the blood flows, enabling more time for gas exchange.
The oxygenated blood from the lungs then goes back through the heart to be pumped out at a higher pressure to the rest of the body. This is important to ensure that the blood reaches all the respiring cells in the body.
Tissue fluid is the liquid that surrounds cells. What does it contain?
1 water
2 glucose
3 amino acids 4 fatty acids
5 ions
6 oxygen
How tissue fluid is formed?
Capillaries have small gaps in the walls so that liquid and small molecules can be forced out.
As blood enters the capillaries from arterioles, the smaller diameter results in a high hydrostatic pressure so water, glucose, amino acids, fatty acids, ions and oxygen are forced out. This is known as ultrafiltration. Red blood cells, large proteins and platelets are too big to fit through the tiny gaps, so they remain within the capillary.
Describe How the liquid is reabsorbed?
Large molecules remain in the capillaries and therefore create a lowered water potential.
Towards the venule end of the capillaries, the hydrostatic pressure is lowered due to the
loss of liquid, but the water potential is very low due to the proteins that remained within the capillary. Therefore, water re-enters the capillaries by osmosis at the venule end.
Not all the liquid will be reabsorbed by osmosis, as equilibrium will be reached.
How is the rest of the liquid reabsorbed?
The rest of the liquid is absorbed into the lymphatic system and eventually drains back into the bloodstream near the heart. This liquid that is transferred in the lymphatic system is called lymph.
What unique properties does cardiac muscle have?
- It is myogenic, meaning it can contract and relax without nervous or hormonal stimulation
- It never fatigues, as long as it has a supply of oxygen
Describe the location and function of coronary arteries.
These are the blood vessels that supply the cardiac muscle with oxygenated blood. They branch off from the aorta.
Which ventricular wall is thickest and why?
The left ventricle has a much thicker muscular wall in comparison to the right ventricle to enable larger contractions of the muscle to create a higher pressure to pump blood around the body
