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AQA AS Level Biology > Mass Transport In Animals & Animals 3.3.4.1/2 > Flashcards

Mass Transport In Animals & Animals 3.3.4.1/2 Flashcards

1
Q

What are the reactants constantly needed provided for metabolism?

A

Oxygen and Glucose

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2
Q

Why cannot larger organisms use diffusion?

A

Larger organisms have multiple layers of cells and so diffusion paths are greater

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3
Q

What solves the problem of larger organisms not being able to use just diffusion?

A

A mass transport system

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4
Q

What is a mass transport system?

A

Bulk movement of gases or liquids in one direction via a system of vessels or tubes

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5
Q

What is the difference between a closed circulatory system and an open circulatory system?

A

Closed
Blood is pumped around the body and always contained within a network of blood vessels

Open
Blood is not contained within blood vessels and blood is pumped directly into body cavities

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6
Q

What is a double closed circulatory system?

A

In one complete circuit of the body, blood passes through the heart twice

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7
Q

What is the pulmonary and systemic circulatory system?

A

Pulmonary circulatory system
Right side of the heart pumps deoxygenated blood to lungs for fas exchange

Systemic circulatory system
Blood returns to left side of the heart so oxygenated blood can be pumped around the body

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8
Q

What is the coronary arteries function?

A

To supply the cardiac muscle cells with nutrients and remove waste products

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9
Q

What is the sound the heart makes and what are they caused by?

A

S1 - Lub - Closing of the AV valves
S2 - Dub - Closing of the SL valves

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10
Q

What happens in atrial systole?

A

Walls of atria contact so atrial volume decreases and pressure increases which force the AV valves open. This pushes blood into the ventricle which causes a slight increase in ventricular pressure

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11
Q

What is ventricular systole?

A

Walls of ventricle contract so ventricular volume decreases and pressure increases which forces the AV valves to close (preventing backflow). Ventricular rises above pressure in arteries which force SL valves open and blood through.

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12
Q

What is cardiac diastole?

A

Ventricles and atria are both relaxed and ventricular pressure drops below artery pressure so SL valves close. Atria fills with blood again

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13
Q

Advantage and disadvantage of a double circulatory system

A

Disadvantage
High pressure needed to pump blood around the body

Advantage
Lower pressure needed in lung capillaries for gas exchange

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14
Q

What is the septum?

A

Divides left and right side of the heart

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15
Q

What type of blood is transported from vena cava and where does it go?

A

Deoxygenated blood into the right atrium from body.

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16
Q

What type of blood is transported from pulmonary artery and where does it go?

A

Deoxygenated blood to the lungs.

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17
Q

What type of blood is transported from pulmonary vein and where does it go?

A

Oxygenated blood into the heart from lungs.

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18
Q

What type of blood is transported from aorta and where does it go?

A

Oxygenated blood leaves the heart to the body.

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19
Q

Properties of myogenic muscle

A

Myogenic so contract and relax without need for stimulation.
Never fatigues as long as it has glucose or oxygen.

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20
Q

Cardiac output equation

A

Cardiac output = heart rate x stroke volume

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21
Q

What is cardiac output?

A

Volume of blood leaving the ventricle in one minute.

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22
Q

What is stroke volume?

A

Volume of blood leaving heart per beat.

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23
Q

What is the cardiac cycle?

A

Series of events that happen within one heart beat.

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24
Q

Structure of valves

A

Cusps of tough, flexible tissue attached to muscle by tendons.

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25
Purpose of valves
Prevent back flow
26
What happens when there is greater pressure in front of the valve
The valve shuts
27
What is the structure level of haemoglobin? Why?
Quaternary structure as it has 4 polypeptide chains
28
What is each polypeptide chain associated with?
A haem group
29
Function of a haem group?
Responsible for the transportation of oxygen molecules and carbon dioxide through the bloodstream
30
What does a haem group contain? What does the do and so make?
An iron ion which combines with a singular, whole O2 molecule. Makes 4 O2 molecules carried by a single haemoglobin.
31
How does haemoglobin efficiently transport oxygen?
Readily associate with oxygen at the surface area where gas exchange takes place. Readily dissociate from oxygen at tissues requiring oxygen.
32
What is the structure of haemoglobin at primary, secondary and tertiary?
Primary - 4 polypeptide chains Secondary - Each polypeptide coils into an alpha helix Tertiary - Each polypeptide folds into a precise shape
33
What does high and low affinity mean?
High affinity = Readily associates Low affinity = Readily dissociates
34
What does a high affinity haemoglobin for oxygen mean? Whats an example?
Oxygen is taken up more easily but is released less readily. Organisms in an environment with little oxygen.
35
What does a low affinity haemoglobin for oxygen mean? Whats an example?
Oxygen is taken up less easily but is released more readily. Organisms with a high metabolic rate requiring more oxygen to tissue.
36
What does loading mean?
Process where haemoglobin binds with oxygen.
37
What does unloading me?
Process where haemoglobin unbinds to oxygen.
38
Process on how haemoglobin travels around the body?
Oxygen diffuses from alveoli into capillaries and intro red blood cells where it associates to form oxyhemoglobin. Travels to muscle or tissue. Disassociates and releases oxygen.
39
Why is carbon monoxide dangerous in the body in context to haemoglobin?
CO more readily binds to haemoglobin than oxygen as it has a higher affinity. Reducing the amount of oxygen being transported around the body.
40
How does tissue hypoxia happen in the body?
COhb is the dominant form when CO is present so oxygen is not delivered effectively and hypoxia occurs.
41
What shape is the oxygen-haemoglobin dissociation curve?
A signoid shape
42
What is positive cooperating?
Once one O2 molecule associates, the rest quicker and more readily also associate as their shape slightly changes in response.
43
Why is the oxygen-haemoglobin dissociation curve have a slow gradient at first?
As the initial shape makes the oxygen hard to bind to any of the four sites at first.
44
Why does the gradient become steeper on the oxygen-haemoglobin dissociation curve?
As one oxygen molecule manages to bind which leads to positive cooperating. The quaternary structure so it easier for other subunits to bind. Thus a smaller increase in partial pressure is required to ind the second and third subunit which steepens the gradient.
45
Why does the gradient level off on the oxygen-haemoglobin dissociation curve?
After binding the third molecule, it is less likely the oxygen molecule will find the empty site so curve flattens off.
46
What is the chemical 2,3-DPG?
The chemical controlling haemoglobin loading
47
What is the affinity of left shift?
Increased affinity of O2
48
What is the properties of left shift?
Lower/Less... Partial pressure of oxygen Alkaline 2,3-DPG Temperature
49
What is the affinity of right shift?
Decreased affinity for O2
50
What is the properties of right shift?
Higher/more... Partial pressure of oxygen Acidic 2,3-DPG Temperature
51
Loading or unloading reversible equation
Hb + 4O2 <--> HbO8 Haemoglobin + oxygen <--> oxyhaemoglobin
52
What are conditions which affect haemoglobin affinity for oxygen?
Partial pressure of oxygen Haemoglobin saturation Partial pressure of carbon dioxide
53
How does oxygen saturation affect affinity for oxygen?
As each molecule binds, it becomes easier for the next to bind due to positive cooperation (slight change in quaternary structure). However as saturation of oxygen increases, it becomes harder for final oxygen molecule to bind.
54
Where is partial pressure of oxygen high? What happens here?
The lungs. Haemoglobin have a higher oxygen affinity and so a higher oxygen saturation.
55
Where is partial pressure of oxygen low? What happens here?
In respiring tissues. Haemoglobin have a lower oxygen affinity and so a lower oxygen saturation.
56
Why do foetus in the womb have a higher affinity?
Has a different structure to have a higher affinity since it needs to steal oxygen from the mother via the placenta and is more reluctant to dissociate. The higher affinity is the reason why foetus can load the oxygen more.
57
Why do animals in a low oxygen environment have a higher affinity?
Haemoglobin needs a much higher affinity for loading more at a partial pressure to make sure enough oxygen is absorbed.
58
Why do small organisms with a high metabolic rate have a lower affinity?
Smaller SA:V mean they loose heat more quickly so have a higher metabolic temperature to keep temperature. This requires a lower affinity so oxygen can easily unload.
59
What is the Bohr effect?
After right shift and the pH decreases, the tertiary structure of haemoglobin is altered which decreases its affinity for oxygen and so increasing the dissociaton of oxygen.
60
What is partial pressure of oxygen?
Concentration of oxygen in the air or dissolved in a solution

AQA AS Level Biology (5 decks)

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