💚 3.3 Topic 3 - 3.3.4 Mass transport - 3.3.4.1 Mass transport in animals Flashcards
1
Q
Is haemoglobin a large or small protein?
A
Large.
2
Q
What level of protein structure is haemoglobin in?
A
Quaternary.
3
Q
How many polypeptide chains is haemoglobin made from?
A
4.
4
Q
What group does each polypeptide chain have? + what ion does it contain?
A
Haem group, which contains an iron ion.
5
Q
True or false? The haem group in haemoglobin gives it its red colour.
A
True.
6
Q
Does haemoglobin have a high or low affinity for oxygen?
A
High.
7
Q
How many oxygen molecules can each haemoglobin molecule carry?
A
4.
8
Q
What forms when oxygen joins to haemoglobin in red blood cells in the lungs?
A
Oxyghaemoglobin.
9
Q
Is it a reversible reaction? + how?
Haemoglobin + oxygen = oxyheamoglobin.
A
Yes. When oxygen leaves oxyhaemoglobin [dissociates from it] near the body cells, it turns back to haemoglobin.
10
Q
What does haemoglobin saturation depend on?
A
Depends on the partial pressure of oxygen.
11
Q
What is the partial pressure of oxygen a measure of?
A
Oxygen concentration in a cell.
12
Q
The greater the concentration of dissolved oxygen in cells, the _ _ _ _ _ _ the partial pressure.
A
Higher.
13
Q
What is the partial pressure of carbon dioxide a measure of?
A
Carbon dioxide concentration in a cell.
14
Q
What does haemoglobins affinity for oxygen depend on?
A
The partial pressure of oxygen.
15
Q
Oxygen loads onto haemoglobin to form oxyhemoglobin where there is a _ _ _ _ partial pressure of oxygen.
A
High.
16
Q
Oxyhemoglobin unloads its oxygen where there is a _ _ _ _ _ partial pressure of oxygen.
A
Lower.
17
Q
Do alveoli have a high or low partial pressure of oxygen to allow oxygen to load onto haemoglobin to form oxyhaemoglobin?
A
High.
18
Q
What happens to the partial pressure of oxygen in cells when they respire?
A
It is lowered.
19
Q
What does a dissociation curve show?
A
It shows how saturated the haemoglobin is with oxygen at any given partial pressure.
20
Q
Where the partial pressure of oxygen in high, haemoglobin has a high _ _ _ _ _ _ _ _ for oxygen, so it has a high saturation of oxygen.
A
Affinity.
21
Q
Where the partial pressure of oxygen in low, haemoglobin has a low _ _ _ _ _ _ _ _ for oxygen, meaning it releases oxygen rather than combining with it, so it has a low saturation of oxygen.
A
Affinity.
22
Q
Why is the dissociation ‘S-shaped’?
A
Because when haemoglobin combines with the first oxygen molecule, its shape alters making it easier for the second and third oxygen molecule to bind. However, as the haemoglobin molecule becomes saturated it makes it harder for the fourth oxygen molecule to bind.
23
Q
Does haemoglobin give up its oxygen more readily at higher partial pressures of carbon dioxide?
A
Yes.
24
Q
When cells respire they produce carbon dioxide which raises the partial pressure of what?
A
Carbon dioxide.
25
Give a definition for oxygen unloading.
The rate at which oxyhaemoglobin dissociates to form haemoglobin and oxygen.
26
Using the Bohr effect, when does the dissociation curve shift to the right?
27
Organisms that live in environments with a low concentration of oxygen have haemoglobin with a _ _ _ _ _ _ affinity for oxygen than human haemoglobin.
Higher.
28
Is the dissociation curve to the left or right of ours when ...
Organisms that live in environments with a low concentration of oxygen have haemoglobin with a higher affinity for oxygen than human haemoglobin.
Left.
29
Organisms that are very active and have a high oxygen demand have haemoglobin with a _ _ _ _ _ affinity for oxygen than human haemoglobin.
Lower.
30
Is the dissociation curve to the left or right of ours when ...
Organisms that are very active and have a high oxygen demand have haemoglobin with a lower affinity for oxygen than human haemoglobin.
Right.
31
Do multicellular organisms like mammals have a low or high surface area to volume ratio?
Low.
32
What is the circulatory system made up of?
The heart and blood vessels.
33
What are the names of all the blood vessels which enter the heart, lungs and kidneys?
{5}
Pulmonary vein
Aorta
Hepatic artery
Hepatic portal vein
Renal artery
34
What are the names of all the blood vessels which leave the heart, lungs and kidneys?
{4}
Pulmonary artery
Vena cava
Hepatic vein
Renal vein
35
Name the three different blood vessels.
Arteries, arterioles and veins.
36
Do arteries carry blood from the heart to the rest of the body or from the body to the heart?
From the heart to the rest of the body.
37
What are the artery walls like?
Narrower lumen that veins
Thick
Muscular
Have elastic tissue {stretch and recoil as heart beats = helps maintain the high pressure}
38
The inner lining {endothelium} in arteries is _ _ _ _ _ _ to allow the artery to stretch? + What does this feature help to maintain?
Folded.
High pressure.
39
Which arteries are the only arteries which carry deoxygenated blood to the lungs rather than oxygenated blood to the body?
Pulmonary arteries.
40
What layers are arteries made from?
The endothelium, a thick muscle layer and the elastic tissue located in the wall.
41
What are the smaller vessels called which arteries are divided into?
Arterioles.
42
How is blood directed to different areas of demand in the blood?
By muscles which are inside the arterioles.
43
What do the muscles inside the arterioles do?
They contract to restrict the blood flow or relax to allow full blood flow.
44
Do veins take blood back to the heart or away from the heart?
To the heart.
45
Is blood at high or low pressure in the veins?
Low.
46
What are veins walls like?
Wider lumen that arteries
Very little elastic
Very little muscle tissue
47
True or false veins have valves?
True.
48
Which veins are the only veins which carry oxygenated blood to the heart rather than deoxygenated blood?
Pulmonary veins.
49
What do arterioles branch off into?
Capillaries.
50
Give two examples of substances which are exchanged between cells and capillaries.
Glucose and oxygen.
51
What are adaptations capillaries have which allows them to carry out efficient diffusion?
1} Found very near cells which are in exchange tissues so SDP.
2} Their walls are only one cell thick so SDP.
3} There are a large number of capillaries so increase SA.
52
What are networks of capillaries in tissue called?
Capillary beds.
53
What is tissue fluid?
Tissue fluid is the fluid that surrounds cells in tissues.
54
What is tissue fluid made from?
Small molecules that leave the blood plasma {oxygen, water and nutrients}.
55
What does tissue fluid {unlike blood} not contain? Why?
Red blood cells and big proteins because they are too large to be pushed through capillary walls.
56
What do cells release into tissue fluid once they have taken in the oxygen and nutrients from inside it?
Metabolic waste.
57
By what process in a capillary bed do substances move out of the capillaries and into the tissue fluid by?
Pressure filtration.
58
Describe the process of pressure filtration.
1} At the arteriole end the hydrostatic {liquid} pressure inside the capillaries is greater than the hydrostatic pressure in the TF.
2} Therefore, there is an overall outward pressure which forces fluid out of the capillaries and into the spaces around the cells, forming TF.
3} As fluid leaves, the hydrostatic pressure reduces in the capillaries - so the hydrostatic pressure is much lower at the venule end of the capillary bed {nearest to the veins}.
4} Due to the fluid loss, and an increasing concentration of plasma proteins, the water potential at the venule end of the capillary bed is lower than the water potential in the tissue fluid.
5} Therefore, some water re-enters the capillaries from the tissue fluid at the venule end by osmosis.
59
What system is any excess tissue fluid drained into?
Lymphatic system.
60
What does the lymphatic system do with the tissue fluid which has drained into it?
It transports this excess tissue fluid from the tissues and puts it back into the circulatory system.
61
What can high blood pressure which means a high hydrostatic pressure in the capillaries lead to?
An accumulation of tissue fluid in the tissues.
62
What blood does the right side of the heart pump and where to?
Deoxygenated blood to the lungs.
63
What blood does the left side of the heart pump and where to?
Oxygenated blood to the whole body.
64
Why does the left ventricle of the heart have thicker and more muscular walls?
Because it needs to contract powerfully to pump blood all the way round the body.
65
Why do the ventricles have thicker walls than the atria?
Because they have to push blood out of the heart whereas the atria just need to push blood a short distance into the ventricles.
66
Why do the cords attach the atrioventricular valves to the ventricles?
To stop them being forced up into the atria when the ventricles contract.
67
If there's _ _ _ _ _ _ pressure behind a valve, it's forced _ _ _ _.
Higher
Open
68
When ventricles relax, atria what?
Contract.
69
When ventricles contract, atria what?
Relax.
70
When at a high pressure which artery and vein lead the atria to fill up when blood returns to the heart?
Vena cava and pulmonary vein.
71
What is cardiac contraction also called?
Systole.
72
What is cardiac relaxation also called?
Diastole.
73
What formation do most cardiovascular disease start with?
Atheroma formation.
74
How does an atheroma form?
If damage occurs to the endothelium in an artery which is usually smooth and unbroken, white blood cells and lipids from the blood will clump together under the lining to form fatty streaks. Overtime, this builds up and hardens, which forms fibrous plaque (an atheroma).
75
In short terms what is an atheroma?
It is fibrous plaque formed from a build up of white blood cells and lipids and connective tissue over a period of time.
76
Why are atheromas bad?
The plaque partially blocks the lumen of the artery which causes blood flow to be restricted, leading to an increase in blood pressure.
77
What type of disease is coronary heart disease?
Cardiovascular disease.
78
When does coronary heart disease which is a type of cardiovascular disease occur?
It occurs when the coronary arteries have a lot of atheroma in them. This restricts blood flow to the heart muscle. It can lead to myocardial infarction.
79
What are two diseases which atheromas increase the risk of?
Aneurysm and thrombosis.
80
In simple terms what is an aneurysm?
A ballon-like swelling of the artery.
81
How do atheromas cause aneurysms?
1} The fibrous plaque damages and weakens the arteries. Also narrowing them, increasing blood pressure.
2} When blood travels through a weakened artery at high pressure, it may push the inner layers through the outer plastic layer to form an aneurysm. T
3} The aneurysm could burst leading to a haemorrhage.
82
What can an aneurysm lead to if it bursts?
A haemorrhage {bleeding}.
83
In simple terms what is a thrombosis?
A formation of a blood clot.
84
How do atheromas cause thrombosis?
1}If an atheroma plaque ruptures the endothelium, the artery wall is now damaged as a rough surface is left.
2} Platelets and fibrin which is a protein accumulate at the damage and form a blood clot {a thrombus}.
3} This blood clot can cause an artery to become completely blocked/can come dislodge and cause one elsewhere.
5} Debris from the rupture can lead to another blood clot which forms further down the artery.
85
What is a myocardial infarction caused by?
Interrupted blood flow to the heart.
86
What happens if a coronary artery becomes completely blocked {e.g. by a blood clot}]?
An area of the heart muscle will be totally cut off from its blood supply, receiving no oxygen.
87
What is a myocardial infarction more commonly known as?
A heart attack.
88
What can a heart attack cause?
Damage and death of the heart muscle.
89
What are symptoms of a heart attack?
Pain in the chest and upper body, shortness of breath and sweating.
90
What are 3 factors which increase the risk of cardiovascular disease?
1} High blood cholesterol and poor diet.
2} Cigarette smoking.
3} High blood pressure.
91
Why does high blood cholesterol and poor diet increase your risk of cardiovascular disease?
Cholesterol is one of the main parts of the fatty deposits that form atheromas = increased blood pressure and blood clots = block flow of blood to coronary arteries = myocardial infarction.
A diet high in saturated fat is associated with high blood cholesterol levels.
A diet high in salt also increases the risk of cardiovascular disease because it increases the risk of high blood pressure.
92
Why is cigarette smoking a risk factor of cardiovascular disease?
Cigarette smoke has both nicotine and carbon monoxide in it.
Nicotine = increases the risk of high blood pressure.
Carbon monoxide = combines with haemoglobin and reduces the amount of oxygen transported in the blood = reduces amount of oxygen available to tissues = if heart muscle does not receive enough oxygen = heart attack.
Smoking decreases the amount of antioxidants in the blood {protect cells from damage} = cell damage in the artery walls = atheroma formation.
93
Why is having high blood pressure a risk factor for cardiovascular disease?
High blood pressure increases the risk of damage to the artery walls. Damaged walls have an increased risk of atheroma formation = increase in blood pressure & {atheromas can cause blood clots = block flow of blood to heart muscle = heart attack}.
94
Give some risk factors of cardiovascular disease which cannot be controlled?
Having a genetic predisposition to coronary heart disease, having high blood pressure as a result of another condition e.g. diabetes.
