Topic 7: Mass transport Flashcards
(69 cards)
Briefly describe the diff levels of protein structure
- Primary structure - sequence of amino acids
- Secondary structure - local motifs held by hydrogen bonding(alpha helices and b pleated sheets)
- Tertiary structure - 3D structure, held by hydrogen bonding, ionic bonds, disulfide bridges, covalent bonds
- Quaternary structure - multiple polypeptide chains bonded together by hydrogen bonds, ionic bonds, covalent bonds
What kind of structure do haemoglobins have?
Quaternary structure with 4 polypeptide chains
What do haemoglobins consist of?
Four polypeptide chains, each with a heme group and iron at the centre
How many oxygens can haemoglobin carry at any one time
4
At what kind of partial pressures does myoglobin bind at
Low partial pressues
What is myoglobin
A related heme protien that acts as an oxygen binding protien
Where do you find Myoglobin?
In muscle tissues
What does Myoglobin serve as
It serves as a site for intracellular oxygen storage, binding oxygen in very low partial pressues.
What is “affinity of haemoglobin for oxygen”
The ability of haemoglobin to attract or bind to oxygen
What is “saturation of haemoglobin with oxygen”
When haemolgobin is holding the maximum amount of oxygen that it can bind to
What is “loading/association of haemoglobin”
The binding of oxygen to haemoglobin
What is “unloading/dissociation of haemoglobin”
When oxygen detatched or unbinds with haemoglobin
Where is oxygen loaded/unloaded
(give examples aswell)
Loaded - high partial pressure of oxygen (alveoli)
Unloaded - low partial pressure of oxygen (resporing tissues)
What is the affinity of haemoglobin like at low partial pressures
Low affinity to oxygen, unloads
What is the haemoglobin like at high partial pressues
High partial pressures = fully saturated hameoglobin, loading
What happens when the first oxygen has bonded to the haemoglobin
a slight conformational change occurs in the haemoglobin
Why does the haemoglobin undergo a conformational change?
I then becomes easier for the other 3 oxygens to bind to the haemoglobin
What is cooperative binding
When the haemoglobin undergoes a conformational change to allow oxygen to easily bind to it.
What is the Bohr Effect?
When a high concentration of CO2 cuses the dissociation curve to shift to the right
Explain the Bohr Effect
- When there is CO2 and H2O, you will form carbonic acid
- Which has an acidic, lower pH
- The lower pH causes the slight conformational change in the haemoglobin
- Which decreases its affinity for oxygen
- Shifting the curve to the right
Why is haemoglobin being able to change its affinity advantageous to organisms
They can adapt to their environment, for example in an environment with more/less CO2 present, mammals with ater metabolism etc.
Where does the foetal haemoglobin dissociation curve shift?
Shifts to the left
Explain the shift of disocciation curve, for foetal haemoglobin
- higher affinity for O2
- shifts to the left for given partial pressure
- needs to grab as much oxygen from mothers blood (through placenta) as possible
Where does the dissociation curve shift to for Llamas
Shifts to the left