circulatory systems Flashcards
what is the function of haemoglobin
co transportation of oxygen and carbon dioxide through the blood stream
Readily associate with oxygen at the surface where gas exchange occurs and readily dissociate from oxygen at respiring tissues
What is the function of blood?
Carry substances around the body
What are the features of haemoglobin?
It is a protein found in an erythrocyte
It is made up of four polypeptide chains
It is a quaternary protein
Each chain is associated with a haem group
It contains an iron ion
Can carry four oxygen molecules at a time (fully saturated)
What is the process of oxygen transportation?
Haemoglobin transport oxygen from the lungs to respiring tissues
Including picking up oxygen at lungs (loading)
Transporting
Dropping oxygen off at tissues ( unloading)
Why is carbon monoxide dangerous?
It takes the place of oxygen in haemoglobin as it is easier to bind making it harder to get oxygen to respiring tissue in the lungs
What does fully saturated mean?
Haemoglobin is bound to 4 oxygen molecules forming Oxy haemoglobin
What are the two contradictory jobs of haemoglobin?
Loading oxygen at lungs
Unloading oxygen at respiring tissues
Why can’t we do both loading and unloading of oxygen at the same time?
Oxygen partial pressure
Shape of haemoglobin
Carbon dioxide partial pressure
PH
Temperature
What is partial pressure a measure of?
It’s a way of measuring the proportion of a mixture of gases that are specific gas occupies similar to concentration
Give an example of low partial pressure of oxygen
Respiring cells using oxygen and producing carbon dioxide
Is respiring cell use oxygen and produce carbon dioxide an example of low or high partial pressure of oxygen?
Low
Give an example of high partial pressure of oxygen
Site of alveoli
When is is partial pressure of oxygen higher
When there is a higher affinity of haemoglobin for oxygen so oxygen loads easier
When is partial pressure of oxygen lower?
When there is a low affinity of haemoglobin for oxygen so oxygen unloads easier
How does the saturation of haemoglobin affect the affinity for oxygen?
When there is a high affinity for oxygen, one oxygen loads with difficulty so haemoglobin changes shape and makes it easier for oxygen to bind
More oxygen binds and haemoglobin becomes more saturated, losing affinity
What happens during the Bohr effect
Carbon dioxide is loaded onto haemoglobin as oxygen is unloaded,
More oxygen is readily loaded into respiring tissue
How does the partial pressure of carbon dioxide affect affinity of haemoglobin at high partial pressure of oxygen
Low partials pressure of carbon dioxide= haemoglobin has a higher affinity for oxygen meaning it loads easier
Higher partial pressure of carbon dioxide=
Haemoglobin has a lower affinity for oxygen so it unloads easier
If there is a higher affinity for carbon dioxide , which way it does the curve shift on a graph
Left
If hemiglobin has a low affinity for carbon dioxide which way does the curve shift on a graph?
Right
If there is a high oxygen demand in the body, is there a low or a high affinity?
Low affinity as oxygen is unloaded at respiring tissues easier
If there is a higher affinity for oxygen, which way does it shift on the graph?
Left- oxygen is easy to load
If there was a lower affinity for oxygen which way does the curve shift on the graph?
Right- oxygen easy to unload
Give an example of an organism to show the partial pressure of oxygen and saturation of haemoglobin on the graph
Lugworm-
They are not active, live in sand burrows, and have low oxygen availability
The curve shifts to the left as there is a low partial pressure of oxygen and a higher affinity
Do smaller organisms have a small metabolic rate?
Yes
They have a high oxygen affinity