Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

level: 7.1 Haemoglobin

Questions and Answers List

level questions: 7.1 Haemoglobin

QuestionAnswer
Structure of haemoglobin- Large protein, quaternary structure - Made up of 4 polypeptide chains - Each chain has a haem group - High affinity for oxygen
Haem group- Has iron ions - Gives haemoglobin its red colour
Affinity for oxgyen meaning- Tendency to combine with oxygen
High affinity for oxygen- Each molecule carries 4 oxygen molecules - In lungs, oxygen binds to haemoglobin in red blood cells - Forms oxyhaemoglobin
Reaction of forming oxyhaemoglobin- Reversible reaction - When oxygen leaves oxyhaemoglobin (dissociates from it) near body cells - Turns back to haemoglobin
Reaction of haemoglobin and oxygen equationHb + 4O2 <-----> HbO8 haemoglobin + oxygen <-----> oxyhaemoglobin
Loading or association meaning- Haemoglobin binding with oxygen - Forms oxyhaemoglobin where there's a high pO2 - In humans, takes place in lungs
Unloading or dissociation meaning- Oxyhaemoglobin releases its oxygen - Where there is a lower pO2 - In humans, takes place in tissues
How high or low affinity of oxygen affects haemoglobin molecules- The higher it is, the easier it is to take up oxygen, but the harder it is to release oxygen - The lower it is, the harder it is to take up oxygen, but the easier it is to release oxygen
The role of haemoglobin- Transports oxygen
2 things must happen for haemoglobin to carry out its function- Readily associate with oxygen at the surface where gas exchange takes place - Readily disassociate from oxygen at tissues requiring it
How it achieves its function- It changes its affinity for oxygen under different conditions - Changes shape in the presence of different substances e.g. CO2 - The new haemoglobin shape binds more loosely to oxygen, releasing it easier
Why are there different haemoglobins- Organisms have different types of haemoglobin with different oxygen transporting capacities - Adaptation that helps organism survive in particular environment
Organisms in environment with low concentration of oxygen- Organisms have haemoglobin with higher affinity for O2 than humans, disassociation curve is to left of humans
Organisms in environment with high concentration of oxygen- Organisms are very active, high O2 demand, have haemoglobin with lower affinity for oxygen than humans, curve is to the right of humans