Biology A03 Flashcards
Where is the haemoglobin found?
In red blood cells
What is the haemoglobin responsible for?
Carrying oxygen around the body because oxygen does not dissolve into the circulatory system.
What is haemoglobin?
It is a large protein and has a quaternary structure (made up of four polypeptide chains).
Describe the polypeptide chain
Each chain has haem group which contains an iron ion (gives it its red colour).
Each haemglobin molecule can carry four oxygen molecules.
The ability for oxygen to bind with the haemoglobin is also known as…
haemoglobin’s affinity for oxygen.
What does haemoglobin’s affinity for oxygen depend on?
The partial pressure of oxygen, which is a measure of oxygen concentration.
Describe the relationship between concentration of oxygen dissolved in cells and the partial pressure.
The higher the concentration of oxygen dissolved in cells, the higher the partial pressure.
As partial pressure increases, haemoglobin’s affinity for oxygen increases too.
How is oxyhaemoglobin formed?
Oxygen associates onto the haemoglobin where there is a high partial pressure of oxygen.
What happens to oxyhaemoglobin?
It unloads the oxygen to where there is a low partial pressure of oxygen and becomes a haemoglobin again.
What do oxygen dissociation curves show?
They show how saturated with oxygen haemoglobin is, which is affected by haemoglobin’s affinity.
What is the partial pressure of carbon dioxide a measure of?
The concentration of Co2 in a cell.
How is oxygen dissociation affcetd?
By the partial pressure of carbon dioxide.
Explain why oxygen dissociation is affected?
When cells respire they produce carbon dioxide.
Haemoglobin dissociates with oxygen easier when there is a…
higher partial pressure of carbon dioxide. This is how the body gets more oxygen to cells when they need it.
What does a high partial pressure of carbon dioxide cause?
The dissociation curve to keep its shape but shift to the right.
What is the bohr effect?
When oxygen saturation is lower at any given partial pressure of oxygen, meaning more oxygen is released.
What is there partial pressure of oxygenlike at high altitudes?
Its reduced, meaning there is less oxygen available in the environment to be used in for respiration.
What does a high altitude cause?
Body produces ore EPO (erythropoietin) in the kidneys and causes an increases in red blood cells.
Why do athletes train at high altitudes?
When they perform at a normal altitude they will have more oxygen carrying red blood cells and therefore easier transport of oxygen.
What does it mean when more oxygen can be transported around the body at once?
Muscles can respire quicker and produce more energy, which is very useful as it can have a big impact on athletes performance.
What is a pulse oximeter?
A non-invasive method of measuring someone’s blood oxygen saturation.
How is a pulse oximeter used?
The device is usually attached to the subject’s finger and works by sending two wavelengths through the finger.
How is a pulse oximeter measured?
By a photodetector as the light exits.
Why can the blood oxygen saturation be determined?
Haemoglobin absorbs light differently depending on its saturation with oxygen.
What is the normal range for blood saturation levels?
95-99%
What does emphysema cause?
Enlarged alveoli by the destruction of alveoli walls, meaning there is a smaller surface are for gas exchnage.
If someone has emphysema what happens to the rate of diffusion.
Rate of diffusion of oxygen in the blood is slowed, meaning they would have a low saturation of oxygen.
How is cystic fibrosis caused?
A faulty gene that disrupts the movement of salt and water around the body which leads to a build up of sticky mucus around the body.
What can the stick mucus cause?
Problems in the airway by widening the walls of the airway, causing bacterial infections and causing blood in the airway.
What is the blood oxygen saturation like for a person with cystic fibrosis?
Much lower.
What is a sphygmomanometers?
Device used to measure blood pressure.
Describe a sphygmomanometers
Usually a rubber cuff and are wrapped around the arm.
Describe how a sphygmomanometers is used
The heart beats, blood is forced through the arteries which causes a rise in pressure known as systolic pressure.
Then followed by a decrease in pressure as the heart’s ventricles prepare for another beat, which is also known as a diastolic pressure.
An example of a typical reading?
120/80
systolic pressure/diastolic pressure
