exchange and transport systems Flashcards
1
Q
the rate of heat loss depends on what
A
surface area
2
Q
animals with a compact shape have a what surface area
A
small surface area
3
Q
why do compact animals have a small surface area
A
minimises heat loss from their surface
4
Q
what are the 2 main adaptations for gas exchange surfaces
A
large surface area
thin walls( one cell thick)
5
Q
where do single celled organisms undergo diffusion
A
on their outer surface
6
Q
why do single celled organism not need a gas exchange system
A
they have a large SA
thin surface and short diffusion pathway
7
Q
where does oxygen enter and leave in fish
A
in water through the mouth and passes out through gills
8
Q
what are the thin plates that make up the gills called
A
gill filaments
9
Q
what do the gill filaments do
A
give a big surface surface area for exchange of gases
10
Q
what are the gil filaments covered in
A
tiny structures called lamellae
11
Q
what is the function of the lamellae
A
increase surface area even more
12
Q
how are he lamellae adapted to carry out diffusion
A
thin surface layer of cells to speed up diffusion and lots of capillaries
13
Q
explain the counter-current system in fish
A
blood flows through lamellae in one direction and water flows in opposite
14
Q
why is the counter current system good in fish
A
it maintains a large concentration gradient between water and blood
15
Q
is there a higher concentration of water or blood naturally in fish and what does this mean
A
water so oxygen diffuses from water into the blood
16
Q
what do insects use for gas exchange
A
air filled pipes called trachae
17
Q
how does air move into the trachea of insects
A
by pipes called spiracles
18
Q
what do the trachae break of into
A
smaller tracheoles
19
Q
how are the trachae adapted and why
A
thin, permeable walls an go directly to individual cells
20
Q
how does carbon dioixide move out of insects
A
towards the spiracles to be released from the atmosphere
21
Q
how do insects move air in and out
A
rhythmic abdominal movements
22
Q
what is the main gas exchange surface on plants
A
on the surface of the mesophyll cells
23
Q
how is the surface of the mesophyll cells adapted for gas exchange
A
have a large surface area
24
Q
where do gases move in and out of in a plant
A
pores in the epidermis called stomata
25
what do insects do if they are loosing too much water
close their spiracles using muscles
26
how are insects adapted to conserve water
have a waxy cuticle and tiny hairs around spiracles which reduces evaporation
27
how are plants adapted to conserve water
guard cells loose water making them flaccid which closes the pores
28
what kind of plants are adapted for extreme conditions
xerophytes
29
how are the stomata adapted in xerophytes
they are sunk in to trap moist air , reducing concentration gradient between leaf and air , reducing evaporation
30
what is inspiration
breathing in
31
what does the layer of hairs on the epidermis do for xerophytes
traps moist air round the stomata
32
what do the curled leaves on xerophytes do
protect the stomata from wind
33
what happens in the first stage of inspiration
what happens in the second stage of inspiration
external intercostal and diaphragm muscles contract
ribcage moves up and out, diaphragm flattens volume of thoracic cavity increases
34
what happens in the 3rd stage of inspiration
lung pressure decreases as volume of thoracic cavity increases
35
what direction does air always flow and what does this mean for the lungs
from high pressure to low pressure so from trachea to lungs
36
what kind of process is inspiration and what does this mean
active process so requires energy
37
what is expiration
breathing out
38
what happens in the first 2 stages of expiration
external muscles relax and internal contract
ribcage move downwards and inwards and diaphragm becomes curved
39
what happens to the volumes in expiration
- thoracic cavity
- lungs
volume of TC decreases so air pressure increases
air is forced out of the lungs as it moved down pressure gradient
40
can expiration be forced
yes
41
what happens during forced expiration
external intercostal muscles relax and internal contract
moving ribcage down and in
42
what can the movement of the intercostal muscles be described as during expiration
antagonistic
43
what are the 2 ways alveoli are adapted for gas exchange
thin exchange surface- one cell thick so a short diffusion pathway
large surface area
44
what is tidal volume
volume of air in each breath
45
what is ventilation rate
number of breaths per minute
46
what is FEV
forced expiratory volume - maximum amount of air you can force out
47
what happens when someone has pulmonary tuberculosis
cells build up a wall of bacteria in the lungs
infected tissue dies and gas exchange susyem is damaged
48
what does reduced tidal volume lead to
less air that can be inhaled with one breath
49
what are some common symptoms of tuberculosis
persistent cough, coughing up blood or mucus
chest pain
shortness of breath
fatigue
50
what is fibrosis and what can it be a result of
formation of scar tissue in the lungs
infection or exposure to asbestos/ dust
51
why is scar tissue bad for the lungs
thicker and less elastic then normal tissue
so lungs arent able to expand so cant hold as much air
52
what does fibrosis result in for the lungs
reduced tidal volume
reduction in rate of gaseous exchange
fast ventilation rate
53
what happens in asthma
airways become inflamed and irritated
54
what happens during an asthma attack
smooth muscle lining contracts and lots of mucus is produced
55
what is a result of the mucus production in asthma
constriction of the airways, reduced air flow so FEV reduced
56
what are some symptoms of asthma
wheezing
shortness of breath
increased ventillation rate
57
what is emphysema caused by
smoking or air pollution
58
what does emphysema cause
inflammation which attracts phagocytes to the area which produce an enzyme which breaks down elastin
59
what impact does emphysema have
destruction of alveoli walls which reduces surface area and causes a gas exchange decrease
60
what impact does emphysema have on ventilation rate and why
increases as they try to increase amount of air reaching lungs
61
what did the EU do as a result of high emisions
set upper limits for the 4 major pollutants in the atmosphere
62
what happens to molecules in digestion
large molecules are hydrolysed and broken down into smaller ones
63
what enzyme breaks down carbohydrates
amylase into maltose
64
where is amylase produced
in the salivary glands
65
what is a membrane- bound disaccharide and why is it significant
enzymes that are attached to cell membranes of epithelial cells
they help break down disaccharides into monosaccharides
66
what do lipase enzymes do
catalyse the breakdown of lipids into monoglycerides and fatty acids
67
what bond does lipase break in lipids
ester bond
68
where are lipases made and where do they work
made in pancreas and work in small intestine
69
what are bile salts and what is their purpose
produced in liver ad they emulsify lipids
70
what does emulsify mean
break down
71
why is the breaking down of lipids so important
breaking down lipids increases their surface area
72
what happens once the lipid has been broken down
monoglycerides and fatty acids stick with bile salts to form micelles
73
what do endopeptidases aim to do
hydrolyse peptide bonds within a protein
74
what is an example of an endopeptidase
pepsin
75
what do exopeptidases aim to do
hydrolyse peptide bonds at ends of protein molecules. they remove single AA from proteins
76
what are dipeptidases
exopeptidases that work specifically on dipeptides
77
where are dipeptidases often located
on the cell surface membrane of epithelial cells in the small intestine
78
how is glucose and galactose absorbed across cell membranes
by active transport with sodium ions using a co- transporter protein
79
how are monoglycerides and fatty acids absorbed
micelles help them towards the cell membrane - which break up and reform
they can then diffuse through
80
how are amino acids absorbed across cell membrane
co-transport
81
how are sodium ions used in the absorption of AA
sodium ions are actively transported out of ileum into blood. creating conc gradient . they the diffuse into ileum through sodium- dependant transporter proteins
82
what is the circulatory system made up of
heart and blood vessels
83
aorta
oxygenated blood to body
artery
84
pulmonary artery
deoxygenated blood to lungs
85
vena cava
vein
deoxygenated blood to heart
86
renal vein
deoxygenated blood to kidney
87
renal artery
oxygenated blood to kidney
88
how are the arteries adapted
walls are thick and muscular and have elastic tissue to stretch and recoil
inner lining folded to allow artery to stretch
89
what is the function of arterioles
form a network through the body and blood is directed to areas of demand
90
how are veins adapted
wide lumen with very elastic muscle tissue
have valves to stop backflow of blood
91
what are the main adaptations of the capillaries
found near cells in exchange tissues so theres a short diffusion pathway
walls are one cell thick
capillaries increase surface area
92
what is a capillary bed
a network of tissues in capillaries
93
what is tissue fluid
fluid that surrounds cells in fluid
94
at start of capillary bed what is hydrostatic pressure like
greater than hydrostatic pressure in tissue fluid
95
what does this difference in hydrostatic pressure cause
fluid to be forced out into spaces around the cell forming tissue fluid
96
as fluid leaves what happens to hydrostatic pressure
it reduces in capillaries so its lower at the venule end ( one closest to veins)
97
what happens to tissue fluid as a result of fluid loss
the water potential at the venule end is lower then water potential from tissue fluid
so some water re- enters capillaries from tissue fluid by osmosis
98
what type of blood does each side of the heart pump
left side pumps oxygenated and right side pumps deoxygenated
99
how is the left ventricle specialised for its job and why
left ventricle thicker, more muscular walls then right as it needs to powerfully contract to pump blood around body
100
why do the ventricles have thicker walls then the atria
have to push blood out of heart whereas atria push blood to ventricles
101
what is atrioventricular valves( AV ) function
link atria to ventricles to stop blood flowing back into atria when ventricles contract
102
what is the semi- lunar (SL) valves function
link ventricles to pulmonary artery and aorta
103
what happens in the first stage of the cardiac cycle
ventricles are relaxed and atria contract
104
describe the first stage of the cardiac cycle
atria contract
decrease volume and increase pressure pushing blood into ventricles.
105
describe the second stage of the cardiac cycle
atria relax and ventricles contract, increasing pressure. high pressure forces AV valves shut to prevent back- flow. pressure in ventricles higher then aorta and PA so forces SL valves open
106
describe the final stage of the cardiac cycle
ventricles and atria relax
higher pressure in aorta and PA closes SL valves.
blood returns to heart in atria to refill again
107
if damage occurs to the endothelium what happens
white blood cells and lipids clump together forming fatty streaks
108
what is an atheroma and how does it form
WBC, lipids and connective tissue build up
109
why are atheromas bad
they partially block lumen and restrict blood flow causing blood pressure increase
110
what does affinity mean
ability to bind with oxygen
111
haemoglobin has a high what
affinity for oxygen
112
what is the product of oxygen joining with haemoglobin
oxyhaemoglobin
113
what is the partial pressure of oxygen a measure of
oxygen concentration
114
the greater the concentration of dissolved oxygen the what
the higher the partial pressure
115
when does oxygen form oxyhaemoglobin
where there is a high pO2
116
when does oxyhaemoglobin unload oxygen
when there is a low pO2
117
do alveoli have a high or low pO2
high
118
why does loading happen in the alveoli
high pO2
119
when respiration happens does pO2 get higher or lower
lower
120
describe what happens when pO2 is high
high affinity
so high saturation of oxygen
121
describe what happens where pO2 is low
low affinity
low saturation of oxygen
122
what shape can the affinity curve be described as
S shaped
123
what does haemoglobin at high partial pressures of co2 do
gives up oxygen more readily
124
what does respiration do to the rate of oxygen unloading
increases it
125
why does respiration increase the rate of oxygen unloading
higher pCO2 levels
126
which way does dissociation curve shift when higher levels of CO2
to the right
127
organisms that live in low oxygen concentration environments have a what affinity
what way does curve shift
higher then human
left
128
organisms that have high metabolic demand have a what
what way does curve shift
low affinity for oxygen
right
129
Name a three-way adaptations for efficient, diffusion in insects
Large number of tracheoles for a large surface area.
Thin walls in tracheoles  a short diffusion pathway.
Use of oxygen and carbon dioxide, bring the steep diffusion gradient. 
130
What are the three main ways insects prevent water loss?
Waterproof, exoskeleton
Small surface area to volume ratio.
Spiracles.
131
How does the counter current system work in fish?
Water flows in the opposite direction of blood 
132
Describe the process involved in the transport of digestive lipid molecules from ileum to lymph vessels
Micelles contain bile salts and fatty acids.
They help make fatty acids more soluble.
Fatty acids are absorbed by diffusion.
Triglycerides we found in cells.
Vesicles move to cell membrane.
133
How does the movement of sodium out of the cell help with the absorption of glucose into the cell lining of the ileum
Create a concentration gradient.
So sodium moves out by co-transport.
An amino acids move in by facilitated diffusion
134
Describe the role of micelles in the absorption of fats into the cell lining of the ileum
My cells contain bile salts and fatty acids.
How to make fatty acids more soluble
So they can diffuse into the ileum easier.
135
Describe the role of enzymes in the digestion of protein is in a mammal
Hydrolysis breaks peptide bonds.
Endopeptidases produces shorter polypeptide
Exopeptidase act at the end of the protein and produce dipeptides.
Dipeptidase as produces single amino acids. 
136
What are the advantages of lipid droplets?
The increase the surface area so faster hydrolysis
137
What is the significance of the Goldie apparatus in the absorption of lipids?
Processors and packages lipids back into triglycerides.
Combines lipids with proteins
Packages lipids For release
138
Describe the advantage of the counter current principal in gas exchange across a fish gill
Water blood flow in opposite directions.
Maintains a steep concentration gradient.
Diffusion along the lamallae
139
Describe the pathway taken by oxygen molecule from the alveolus to the blood
Through Alveolar epithelium
Into Endothelium 
140
Why does a mouse have a higher metabolic rate than a horse?
Larger surface area to volume ratio.
Mouse has higher rate of respiration.
Mouse has faster heat loss.
141
what is the role of the rough ER for chylomicrons
proteins synthesised by rough ER
vesicle formations
142
what is a chylomicron
contain triglycerides, cholesterol, and other lipids; they have proteins on their surface
143
describe the path by which oxygen goes from alveolus to the blood
-alveolar epithelium
- through capillary epithelium
144
what is the role of the diaphragm in inhilation
diaphragm contracts
flattens increasing chest vol
reduced pressure allows air to enter
145
why is there a difference in thickness between pulmonary artery and pulmonary vein
high pressure of artery smooths out blood flow
146
explain how the thickness of the aorta wall change over time during cardiac cycle
- aorta stretches as pressure increases
- aorta recoils as ventricles relax
-maintains smooth pressure
