mass transport

Question 1

what is in the quatenary structure of haemoglobin that allows it to carry out it’s function

Answer 1

it contains 4 polypeptide chains all with an iron prosthetic group that a single oxygen molecule can bind to

Question 2

with what kind of haemoglobin will more oxygen associate with?

Answer 2

high affinty haemoglobin

Question 3

where will haemoglobin have a low affinity for oxygen

Answer 3

• places where the is a low concentration of oxygen
• in metabollically active organisms
• when there’s a high CO2 concentration

Question 4

why is the oxygen dissociation curve an S shape?

Answer 4

as for the first oxygen it is hard to load
the second and third oxygen is easier to load
the fourth oxygen is hard to load
-due to the change of shape of haemoglobin every time an oxygen associates

Question 5

what does a left shift of the oxygen dissociation curve mean?

Answer 5

• a higher affinity haemoglobin

Question 6

what does a right shift of the oxygen dissociation curve mean?

Answer 6

-a lower affinity haemoglobin

Question 7

what is the process of the bohr effect

Answer 7

1- carbon dioxide reacts with water to form carbonic acid (the reaction is catalysed carbonic anhydrase)
2- H+ ions released as well the hydrogen carbonate ion
3- the presence of the H+ ion lowers Hbs affinity for oxygen so oxygen dissociates and diffuses out of the cell
4-H+ and Hb form HHb

Question 8

in what kind of organisms will low affinity Hb be present? and why?

Answer 8

metabollically active organisms, as oxygen needs to be unloaded quickly for respiration

Question 9

in what kind of organisms will high affinity Hb be present and why?

Answer 9

organisms that live in a low PPO2 enviroment so Hb can be fully saturated at the low partial pressures

Question 10

name two features of a transport system

Answer 10

• they have a closed system of tubular vessels

- a form of mass transport in which the transport medium is moved around in bulk over large differences

Question 11

what is a closed cirulatory system

Answer 11

a circulatory system in which the fluid is contained in vessels

Question 12

what is a open circulatory system

Answer 12

a circulatory system in which the fluid is not contained in vessels

Question 13

what are the features of an atrium

Answer 13

it is thin walled

it is elastic

Question 14

why do ventricles of thicker walls than atria?

Answer 14

as they have to contract strongly to pump blood either to the lungs or rest of the body

Question 15

what is the function of the atrioventricular valves?

Answer 15

they prevent back flow of blood

Question 16

what is the function of the aorta?

Answer 16

it carries oxygenated blood to all parts of the body except the lungs

Question 17

what is the funcation of the coronary arteries?

Answer 17

to carry oxygenated blood to the heart

Question 18

what is the function of the pulmonary artery?

Answer 18

it carries deoxygenated blood to the lungs

Question 19

what is the function of the pulmonary vein?

Answer 19

it carries oxygenated blood from the lungs back to heart

Question 20

what is diastole?

Answer 20

the relaxation of the whole heart both the atria and ventricles

Question 21

what is the loading of oxygen

Answer 21

the process of which oxygen and haemoglobin bind together

Question 22

what is the unloading of oxygen

Answer 22

the process by which haemoglobin releases oxygen

Question 23

what is the role of haemoglobin

Answer 23

to transport oxygen

Question 24

how is haemoglobin efficient at transporting oxygen

Answer 24

it readily associates with oxygen where gas exchange takes place
it readily dissociates with oxygen at tissues requiring it

Question 25

why do hameogolbins have different affinities for oxygen

Answer 25

in different organisms hameoglboin have slightly different amino acid sequences
so has a slightly different tertiary and quaternary structure
hence different oxygen binding properties

Question 26

why do large organisms have a special transport system

Answer 26

as surface area to volume ratio decreases to a point

where needs of the organism cannot be met by the body surface alone

Question 27

what does the presence of a pump and transport medium depend on

Answer 27

the surface area to volume ratio

how active the organism is

Question 28

how is the movment of transport medium in vessels occur in animals

Answer 28

via muscle contraction of either body muscles or of a specalised pump organ

Question 29

how is the movement of transport medium in vessels occur in plants

Answer 29

plants rely on natural processes such as evaporation

Question 30

what kind of circulatory system do mammals have

Answer 30

A closed double circulatory system

blood is confined to vessels and pass twice through the heart for each complete circuit of the body

Question 31

why do mammals have a double circulatory system

Answer 31

as when the blood is passed through the lungs it’s pressure decreases
blood is returned to heart to boost it’s pressure so it can flow to the other tissues

Question 32

outline atrial systole

Answer 32

ventricles relaxed
atria contract decreasing volume of chambers and increasing the pressure
pushing blood into ventricles

Question 33

outline ventricular systole

Answer 33

ventricles contract
atria relax
decreasing their volume increasing their pressure
pressure in ventricles higher than atria
atrioventricular valve shuts
semi lunar valves open as pressure in ventricles higher than in arteries

Question 34

outline diastole

Answer 34

atria and ventricles relax
higher pressure in arteries closes the semi lunar valve
blood returns to the heart and fills the atria again due to high pressure in veins
Atrioventricular valve opens as pressure in ventricles falls allowing blood to flow passively from the atria

Question 35

what is the equation for cardiac output

Answer 35

cardiac output=heart rate x stroke volume

Question 36

what does haemoglobin and oxygen join together to form in the lungs

Answer 36

haemoglobin and oxygen join together in the lungs to form oxyhaemoglobin