Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > ✅7 - Mass Transport > Flashcards

✅7 - Mass Transport Flashcards

(96 cards)

Start Studying
1
Q

What is associating?

A

When haemoglobin binds with oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where does loading take place?

A

In the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is dissociating?

A

When haemoglobin releases its oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where does unloading take place?

A

The tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Haemoglobins with a high affinity for oxygen…

A

…take it up easily but release it less easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Haemoglobins with a low affinity for oxygen…

A

…don’t take it up easily but release it easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the role of haemoglobin?

A

To transport oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What features must haemoglobin have to be efficient at transporting oxygen?

A

Readily dissociate with oxygen at the surface where gas exchange occurs
Readily dissociate from oxygen at the tissues requiring it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When does haemoglobin change affinity?

A

Under different conditions, such as O2 and CO2 concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why do different haemoglobins have different affinities for oxygen?

A

Because they have different shapes as each species produces a different amino acid sequence so the tertiary and quaternary structure are different

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an oxygen dissociation curve?

A

The graph of the relationship between the saturation of haemoglobin and oxygen partial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

At low oxygen concentrations, why does little oxygen bind to haemoglobin?

A

Because the shape of the haemoglobin molecule makes it difficult for the first oxygen molecule to bind to one of the sites on its four polypeptide subunits because they are closely united

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why is it easier for the second oxygen molecule to bind to haemoglobin?

A

Because the binding of the first oxygen molecule changes the quaternary structure of the haemoglobin and uncovers another binding site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is positive cooperativity?
(Mass transport)

A

Binding the first molecule makes binding of the second easier and so on

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens after the binding of the third oxygen molecule?

A

It is harder to bind the fourth, as the majority of the binding sites are filled and it is less likely that a single oxygen molecule will find an empty site to bind to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the shape of the oxygen dissociation curve?

A

Sigmoidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The further the curve is to the left…
(oxygen dissociation graph)

A

…the greater the affinity of haemoglobin for oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The further the curve is to the right…

A

…the lower the affinity of haemoglobin for oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does haemoglobin’s affinity for oxygen change in the presence of carbon dioxide?

A

Its affinity is reduced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the Bohr effect?

A

The greater the concentration of Carbon Dioxide, the more rapidly haemoglobin releases its oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why is a transport system required?

A

To take materials from cells to exchange surfaces and the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What factors does the presence of a transport system depend on?

A

The surface area to volume ratio

How active an organism is

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the features of transport system?

A

A suitable medium in which to carry materials
A form of mass transport
A closed system of tubular vessels
A mechanism for moving the transport medium within vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What do animals use as transport mechanisms?

A

Muscular contraction either of the body muscles or of the organs eg heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What do plants rely on for exchange?
Natural, passive processes such as evaporation
26
What kind of circulatory system to mammals have?
A closed, double system
27
Why does the blood pass through the heart twice for reach circuit of the body?
Because pressure is reduced when the blood is passed through the lungs, and it otherwise would circulate the body very slowly
28
What is the atrium?
A thin walled and elastic chamber which stretches as it collects blood
29
What is the ventricle?
A much thicker, more muscular chamber
30
Why do the ventricles have thicker more muscular walls?
Because they have to contract strongly to pump blood a further distance
31
Where does the right ventricle pump blood to?
The lungs
32
Where does the left ventricle pump blood to?
The rest of the body
33
What are the two valves?
The left atrioventricular (bicuspid) The right atrioventricular (tricuspid)
34
What is the problem with the large surface area needed for the capillaries in the lungs?
There has to be a significant drop in pressure
35
What is the aorta connected to?
The left ventricle
36
What does the aorta do?
Carries oxygenated blood to all parts of the body except the lungs
37
What is the vena cava connected to?
The right atrium?
38
What does the vena cava do?
Brings deoxygenated blood back from the tissues of the body
39
What is the pulmonary artery connected to?
The right ventricle
40
What does the pulmonary artery do?
Carried deoxygenated blood to the lungs where it is replenished with oxygen and carbon dioxide removed
41
What is the pulmonary vein connected to?
The left atrium
42
What does the pulmonary vein do?
Brings oxygenated blood back from the lungs
43
Which blood vessels supply the heart?
The coronary arteries
44
What is a myocardial infarction?
A heart attack
45
Where do the coronary arteries branch off from?
The aorta
46
What is systole?
Contraction
47
What is diastole?
Relaxation
48
What happens in diastole?
Blood returns to atria, pressure rises. AV valves open, blood passes into ventricles, pressure drops and semi lunar valves close
49
What happens in atrial systole?
Contraction of atrial walls forces blood into ventricles from atria
50
What happens in ventricular systole?
Ventricles fill with blood, wall contract, increasing pressure. AV valves shut and backflow prevented. Blood forced out into arteries
51
Where are the atrioventricular valves located?
Between the left atrium and ventricle and the right atrium and ventricle
52
What do the atrioventricular valves do?
Prevent backflow of blood when contraction of ventricles means that ventricular pressure exceeds atrial pressure
53
How do atrio ventricular valves maintain uni-directional flow of blood | Exam Q
Pressure in (left) atrium is higher than in ventricle/B causing valve to open; Pressure in (left) ventricle/B is higher than in atrium causing valve to close;
54
Where are the semi-lunar valves?
In the aorta and pulmonary artery
55
What do the semi-lunar valves do?
Prevent backflow of blood into ventricles when pressure in the vessels exceeds the pressure in the ventricles
56
Where are the pocket valves?
In veins
57
What is cardiac output?
The volume of blood pumped by one ventricle of the heart in one minute?
58
How would you calculate cardiac output?
heart rate x stroke volume (volume of flood pumped out of left ventricle per cardiac cycle)
59
What do arteries do?
Carry blood away from the heart to the arterioles
60
What do arterioles do?
Smaller arteries that control the blood flow from arteries to capillaries
61
How can arterioles reduce blood flow into capillaries
Muscle contracts; Constricts/narrows arteriole/lumen;
62
What do capillaries do?
Tiny vessels that link arterioles to veins
63
What do veins do?
Carry blood from capillaries back to the heart
64
What is the basic structure of arteries, arterioles and veins?
``` Tough fibrous outer layer Muscle layer Elastic layer Thin inner lining Lumen ```
65
What is the function of the tough fibrous layer?
Resists pressure changes from both within and outside
66
What is the function of the muscle layer?
Can contract and so control the flow of blood
67
What is the function of the elastic layer?
Helps maintain blood pressure by stretching and springing back **smoothing blood flow**
68
What is the function of the thin inner lining? (Blood vessels)
Smooth to reduce friction and thin to allow diffusion
69
What is the function of the lumen?
The central cavity, allows blood to flow
70
How are arteries adapted to their function?
Thick muscle layer to constrict and dilate Thick elastic layer to come with high blood pressure Thick wall to resist pressure No valves
71
How are arterioles adapted for their function?
Muscle layer is thicker to allow constriction Thin elastic layer because blood pressure is lower
72
How are veins adapted for their function?
Muscle layer is relatively thin as constriction and dilation can't control blood flow Elastic layer is thin due to low pressure Overall thickness is small, low pressure Valves throughout
73
How are capillaries adapted for their function?
Walls consist mostly of the lining layer Numerous and highly branched Narrow diameter to permeate tissues Narrow lumen to squeeze RBCs flat
74
What is tissue fluid?
A watery liquid that contains glucose, amino acids, fatty acids, ions in solution and oxygen
75
How is tissue fluid formed?
High hydrostatic pressure at the artery end forces the fluid out through the capillary
76
What is ultrafiltration?
Filtration under pressure
77
How is tissue fluid returned to the circulatory system?
The loss of tissue fluid reduces hydrostatic pressure in capillaries, so higher hydrostatic pressure outside forces fluid back in. Water also leaves the tissue by osmosis.
78
How are fluids moved around the body?
Hydrostatic pressure of the tissue fluid Contraction of body muscles
79
How does water move across the cells of the leaf?
Water from mesophyll cells is lost by evaporation from their cell walls to the air spaces in the leaf, then water moves by osmosis into the drier cells
80
What is the main factor responsible for the movement of water up the xylem?
Cohesion tension
81
How does water move up the xylem?
Water evaporates from mesophyll Water molecules form hydrogen bonds and have cohesion Water forms a continuous column down the xylem The column is pulled up the xylem
82
What is transpiration pull?
When a column of water is pulled up the xylem as a result of transpiration
83
What evidence supports cohesion-tension theory?
Tree trunks change in diameter according to the rate of transpiration If a xylem vessel is broken and air enters, a tree can no longer take up water When a xylem vessel is broken, water does not leak out as it would if it was under pressure
84
What is needed to drive the process of transpiration?
Energy from the sun
85
What is translocation?
The process by which organic molecules and some mineral ions are transported from one part of a plant to another
86
What is the phloem?
The tissue that transports biological molecules in flowering plants
87
What is evidence for the fact that translocation occurs in the phloem?
When phloem is cut, a solution of organic molecules flows out Plants provided with radioactive carbon dioxide can be shown to have radioactively labelled phloem
88
Explain the cohesive-tension theory
Water evaporates from mesophyll cells due to the sun and transpiration Water molecules form hydrogen bonds between one another and therefore stick together (cohesion) Water from a continuous unbroken column column which is pulled up
89
Describe the mechanism for translocation
Sucrose is actively transported into phloem By companion cells Lowers the water potential in the phloem **and water enters by osmosis** Produces high pressure Mass transport towards the sink At sink, sugars are removed
90
What are ringing experiments
Cut a ring of bark from around the stem of a plant. After a period of time, the section of stem above the removed area will start to swell This is because sugars are accumulating above the ring
91
What are tracer experiments
Radioactive isotopes are put in CO2 (e.g. carbon 14). The plant will then incorporate this into its sugars which can be tracked through the plant
92
Evidence for the mass flow hypothesis
When a phloem is cut, stuff flows out Plants provide with radioactive CO2 have radioactive carbon in the phloem after a short time Aphids which feed out of the phloem show sucrose conc. variation changes each day A ring experiment leads to accumulation of sugars around the stem
93
2 ways cell surface membranes are adapted for rapid transport
Membrane folded to increase S.A Large number of protein channels/carriers for facilitated diffusion
94
Why should a person be treated with an experimental and established drug at the same time
1. New/old antibiotic does not kill all bacteria; 2. Resistant bacteria will reproduce to produce (more) resistant bacteria; 3. One antibiotic will kill bacteria resistant to the other antibiotic;
95
How do micelles work
1. Micelles include bile salts and fatty acids; 3. Bring/release/carry fatty acids to cell/lining (of the ileum); 5. Fatty acids (absorbed) by diffusion; 6. Triglycerides reform in cells 7. Vesicles move to cell membrane
96
What is a hierarchy
groups within groups with no overlap

Biology (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions