Topic 1- Chapter 1B- Mammalian transport system Flashcards
which mode of transport do smaller , single celled organisms use + reason (3 points)
diffusion
1) as they are smaller organisms. so diffusion is sufficient to meet their requirements.
2) they have a large s.a to volume ratio so diffusion distance is shorter. 3) and their metabolic demands r low , they require less oxygen and food and do not produce a lot co2
how are substances transported in large organisms + reason
they use mass transport systems. diffusion osmosis and active transport
1)to overcome the limitation in meeting the organisms requirements.
2)larger organisms have higher demand of substances which must be transported quickly into the body
3) waste products must be removed quickly
what is mass transport
bulk movement of gases or liquids in one direction, usually via a system of vessels and tubes
closed vs opened circulatory systems
In a closed circulatory system: blood is pumped around the body and is always contained within a network of blood vessels
In an open circulatory system the blood, or blood equivalent, is inside the body cavity and bathes the organs
double vs single circulatory system
Double circulatory systems have two loops; one to the lungs and one to the body. blood flows through heart twice in one circulation
Single circulatory systems have one loop that includes the lungs and the body. blood flows through heart once in one circulation
advantages of closed system
the pressure can be increased to make blood flow more fast
flow can become directed more precisely to organs that need the most nutrient & oxygen
why do birds and mammals have a double circulation (2)
because they are much larger organisms and they require more oxygen and nutrients
and double circulation is needed to maintain a constant internal temperature
advantages of double circulation (2)
prevents the 02 and dob from mixing
the 02 blood can be transported quickly at high pressure
the scientific name of red blood cells
erythrocytes
word and symbol equation of haemoglobin binds with oxygen
4O2+ Hb = Hb4O2
oxygen+ hemoglobin= oxyhaemoglobin
role of hemoglobin in transporting oxygen. complete process + explain haem and bonds etc.
there’s a high oxygen level in lungs and low concentration of 02 in the blood/ rbc. therefore o2 moves out of the lungs by diffusion and into the rbc.
each hemoglobin is made up of 4 haems (subunits) which is a combination of iron and oxygen. every haem group binds to one oxygen molecule. so there’s 4 o2 molecules and 8 oxygen atoms
the hemoglobin binds with oxygen to form oxyhemoglobin
hb+402= hb402
when the first oxygen molecule binds its changes the hemoglobin molecule structure making it easier for the other o2 molecules to bind
what is the form of haemoglobin by nature
it is a protein
how is hemoglobin responsible for c02 transport
respiring tissue cells release c02 which diffused into the blood in 2
what are the 3 ways co2 passes into the blood from respiring tissue cells
dissolve directly In into blood plasma and carried in solution
2- c02 combine with haemoglobin to form carbaminohaemglobin
3- c02 is converted into hyfrogencarbonate ions
how is co2 converted to hydrogen carbonate ion
1- co2 diffuses into rbc
2- co2 reacts with water forming carbonic acid using catalyst carbonic anhydrase
3- carbonic acid disassociates into h+ ions and hc03- (hydrogen carbonate ion)
4- haemoglobin reacts with the hydrogen to prevent it from lowering the PH so hamelgobin acts as a buffer
