Ch7 Haemoglobin Flashcards
1
Q
How structure of haemoglobin affects oxygen transport
A
- four polypeptides in quaternary structure
- each associated with haem group
- each haem binds to one oxygen
- one protein binds to four oxygens
- globular protein
1
Q
Lungs
A
- Co2 removed- low concentration
- pH increases
- high partial pressure oxygen
- haemoglobin structure changes
- higher affinity
- loads oxygen easily
2
Q
Tissue
A
- Co2 produced by respiration
- decreases pH
- low partial pressures of oxygen
- haemoglobin structure changes
- lower affinity
- unloads oxygen easily
3
Q
Affinity
A
- how easily haemoglobin loads and transports oxygen
- level of attraction
4
Q
Role of haemoglobin
A
- transport oxygen
- load oxygen at gas exchange surface
- unload oxygen at respiring tissues
5
Q
Dissociation curve shifted to the right
A
1.haemoglobin less saturated with oxygen
2. at low partial pressure
3. decreased affinity
4. dissociates more readily
5. more oxygen released
6. increased respiration rate
6
Q
Dissociation curve shifted to the left
A
- haemoglobin becomes more saturated
- at lower partial pressure
- increased affinity
- associated more readily
7
Q
What causes pH decrease
A
- aerobic respiration produces CO2
- CO2 dissolves in blood
- increases hydrogen ion concentration
8
Q
Positive cooperativity
A
- first oxygen binds to haemoglobin
- quaternary structure changes
- other haem groups associate oxygen more easily
- o-d curve gradient steepens
9
Q
Organisms in low O2 environment
A
- high affinity
- curve to the left
- readily associates at low partial pressure
10
Q
Active organisms
A
- low affinity
- curve to the right
- dissociates readily
- more oxygen to meet respiration demand
11
Q
Small organisms
A
- low affinity
- curve to the right
- dissociates readily
- more oxygen for high respiration rate
- large SA:vol ratio
- need to generate heat
