mass transport

Question 1

what kind of structure does haemoglobin have

Answer 1

quaternary

Question 2

define a quaternary protein

Answer 2

many polypeptides bonded togteher by peptide bonds

Question 3

describe the structure of haemoglobin

Answer 3

4 polypeptides
each polypeptide is associated with a haem group #

Question 4

what does each haem group contain

Answer 4

Fe2+

Question 5

what does the Fe2+ combine with

Answer 5

o2

Question 6

how many O2 molecule can be carried by a single haemaglobin molecule

Answer 6

4

Question 7

what is the process to which O2 BIND WITH HAEMAGLOBIN CALLED

Answer 7

association

Question 8

why do different haemoglobins have different affinities for oxygen

Answer 8

each species produces a haemoglobin wiht a slightly different amino acid sequence. therefore each species will have a slightly different quaternary structure and therefore different oxygen binding properties .

Question 9

explain oxygen dissociation curves

Answer 9

the initial shape of haemoglobin makes it difficult for the first oxygen to bind to the haem because they are all so close together. therefire concs are low
after the first o2 molecule has binded the haemoglobin changes shape and it akes it easier for other molecules to bind - positive cooperativity because there is a smaller change in partial pressure.
- however after the binding of the third oxygen molecule there trhe haemoglobin becomes saturated and it is now difficult ot bind because there is only one site left.

ON A GRAPH IT IS SLOW THEN INCREASES THEN PLATEAUS

Question 10

how are arteries adapted for their function

Answer 10

thick and muscular with elastic tissue to allow stretch and recoil

Question 11

how are veins adapted to their function

Answer 11

valves to prevent backflow and pooling

Question 12

what do veins capilliaries and arteries have in common

Answer 12

endothelium tissue

Question 13

what are some adaptations of capillaries

Answer 13

endothelium is only one cell thick = short diffusion pathway
large number of capillaries - increases the SA for exchange

Question 14

what si the hydrostatic pressure like at the arteriole end of the capillary

Answer 14

higher than in the tissue fluid

Question 15

what is tissue fluid

Answer 15

watery fluid formed from blood plasma that contains glucose, amino acids, fatty acids, ions in solution and O2

Question 16

how is tissue fluid formed

Answer 16

at the arteriole end the hydrostatic pressure is greater than the hydrostatic pressure in the tissue fluid.
the difference in hydrostatic pressure means that fluid will be forced out of the capillaries and into the spaces to form the tissue fluid.
as fluid leaves the capillary bed the hydrostatic pressure will decrease. therefore at the venule end the hydrostatic pressure is much lower.. BTW PLASMA PROTEINS DO NOT LEAVE.
- due to fluid loss and an increasing conc in plasma proteins the water potential is lower in the venule end than in the tissue fluid therefore some water re- enters via osmosis.

Question 17

what is done with excess tissue fluid

Answer 17

drained into the lymphatic system

Question 18

how are the alveoli adapted for gas exchange

Answer 18

• thin exchange surface - alveolar epithelium is only one cell thick = short diffusion pathway
• large SA

Question 19

which vessels carry oxygenated blood through the heart

Answer 19

aorta
pulmonary vein

Question 20

which vessels carry deoxygenated blood through the heart

Answer 20

vena cava
pulmonary artery

Question 21

where does blood flowing through the aorta go

Answer 21

pushes oxygenated blood around the body

Question 22

where does blood from the vena cava go

Answer 22

deoxygenated blood back from the body tissue

Question 23

where does the pulmonary vein go

Answer 23

brings oxygenated blood back from the lungs

Question 24

where does the pulmonary artery go

Answer 24

carries deoxygenated blood to the lungs

Question 25

how is the heart muscle supplied with oxygen

Answer 25

coronary arteries

Question 26

what will a blockage in the coronary arteries cause

Answer 26

myocardial infarction

Question 27

what does systole mean

Answer 27

contraction

Question 28

what does diastole mean

Answer 28

relaxation

Question 29

describe the cardiac cycle

Answer 29

DIASTOLE
- blood enters the atria and ventricles from pulmonary veins and vena cava
- semi lunar valves are closed
- left and right av valves open
- relaxation of ventricles allows blood to enter from the atria
atria are relaxed and will fill with blood. ventricles are also relaxed.

ATRIAL SYSTOLE
- atria contract to push the remaining blood into ventricles
- semi lunar valves are closed
- left and right AV valves open
- blood is pumped from atria to ventricles
atria contract pushing blood into the ventricles . ventricles remain relaxed

VENTRICULAR SYSTOLE
-blood pumped into pulmonary arteries and aorta
-semi lunar valves open
- left and right AV valves closed
-ventricles contract and walls thicken
atria relax, ventricles contract, pushing blood away from the heart through the pulmonary arteries and aorta

Question 30

how does a valve open

Answer 30

a higher pressure behind it will force it open
pressure gradients and that

Question 31

how do valves remain closed

Answer 31

there is not a high enough pressure to open it from behind and also the higher pressure below it forces it closed.