Circulatory System: Circulatory Fluid and Components of Blood Flashcards
What is the problem encountered by the circulatory fluid of the circulatory system, blood?
Oxygen doesn’t readily dissolve in liquid water, which is the main component of blood.
What are respiratory pigments used for?
They are proteins that transport oxygen, greatly increasing the amount of oxygen that blood can carry.
They transport oxygen through their ability to bind to that molecules - Adaptations!
What is hemoglobin?
Contained in red blood cells, act as respiratory pigments in most vertebrates and some invertebrates.
At the center of hemoglobin protein is IRON
A single hemoglobin molecule can carry _____ oxygen molecules, _____ per iron-containing heme group.
Four; One
What are the oxygen-binding components in arthropods and many molluscs?
Hemocyanin!
A different respiratory pigment!
It is blue, thanks to the copper that is at the center.
What is blood, in composition?
Cells and platelets immersed in plasma.
Plasma + Cellular elements
Plasma = Water, osmoregulation through blood electrolytes (ions) and plasma proteins, substances transported (nutrients, waste products, gases, hormones)
Cellular elements = Leukocytes (WBC) + Platelets + Erythrocytes (RBC)
What are erythrocytes?
Red blood cells - most numerous!
What do erythrocytes contain?
Hemoglobin, an iron-protein that transports oxygen AND carbon dioxide
Carries oxygen where it needs to go, carbon dioxide away from tissues = Reversible binding, with a preference for oxygen
What do mature erythrocytes lack, in mammals?
Nuclei and mitochondria - Sole job = Oxygen buses!
What does the ability to bind depend on?
This binding affinity is thanks to its SHAPE!
Binding at one of the four subunits => Changes protein shape => Changes binding affinities of the other sites (BINDING COOPERATIVITY)
Reversely, if one subunit becomes unbound, the others will tend to do the same
A small change in the partial pressure of oxygen translates into…
Relatively large amounts of oxygen unloading –> STEEP response slope!
A drop in partial pressure (minor change in partial pressure) leads to a much steeper response in oxygen saturation = Highly sensitive!
This is related to the binding cooperativity - positive feedback, snowball effect.
This indicates the likelihood of hemoglobin to bind.
What is the Bohr shift?
A characteristic of hemoglobin, which retain less oxygen at low pH
This has a key effect on the binding ability, by changing the shape of the curve!
What effect does a falling pH have on hemoglobin?
Hemoglobin retain less oxygen at lower pH (more acidic), thus there is a higher concentration of carbon dioxide = The ability to hold to oxygen lessens
Tissues are undergoing INCREASED RESPIRATION –> More rapid unloading of oxygen
As muscles start to work and produce more carbon dioxide, we make our blood more acidic = Faster unloading of oxygen = Increased respiration = When fed oxygenated blood, hemoglobin unloads oxygen really fast.
What evolutionary adaptations do diving mammals have?
- Changing their buoyancy to glide passively (more efficient)
- Decreasing blood supply to muscles (“budgeting”)
- Deriving ATP in muscles from fermentation, once oxygen is depleted
- Storing oxygen in their muscles, thanks to the MYOGLOBIN protein
What are leucocytes?
White blood cells, involved in the innate and acquired immune system = Defense!
