Organisms exchange substances with their environment Flashcards
(104 cards)
1
Q
What is the formula for calculating surface area to volume ratio?
A
Surface Area ÷ Volume
2
Q
What happens to the surface area to volume ratio as the size of an organism increases?
A
It decreases
3
Q
Why do small organisms like amoeba not require special adaptations for gas exchange?
A
They have a large surface area compared to their volume
4
Q
What is a key adaptation that larger organisms have for gas exchange?
A
Mass transport systems
5
Q
Name two adaptations in the small intestines that maximize absorption of digested food.
A
- Villi
- Microvilli
6
Q
What structures are involved in gas exchange for mammals?
A
- Alveoli
- Bronchioles
- Bronchi
- Trachea
- Lungs
7
Q
What is the role of the diaphragm during inhalation?
A
It contracts and moves downwards
8
Q
What do antagonistic muscles refer to in the context of ventilation?
A
Muscles that contract and relax oppositely
9
Q
What is pulmonary ventilation?
A
Total volume of air moved into the lungs in one minute
10
Q
How is pulmonary ventilation calculated?
A
Tidal volume × Ventilation rate
11
Q
What is the primary function of alveoli?
A
Gas exchange
12
Q
How many alveoli are typically found in each lung?
A
Around 300 million
13
Q
What unique feature of alveoli aids in gas exchange?
A
Very thin epithelium to minimize diffusion distance
14
Q
What adaptation do terrestrial insects have for gas exchange?
A
Tracheal system
15
Q
What are sphericals in the context of insect respiration?
A
Valvular openings for gas exchange
16
Q
What are the three methods of gas movement in the tracheal system of insects?
A
- Diffusion
- Mass transport
- Anaerobic respiration during flight
17
Q
What is a challenge terrestrial insects face regarding gas exchange surfaces?
A
Minimizing water loss
18
Q
How do insects limit water loss at their gas exchange surfaces?
A
- Small surface area for gas exchange
- Waterproof exoskeleton
- Ability to open and close sphericals
19
Q
What is the primary adaptation of fish for gas exchange?
A
Gills
20
Q
Why do fish require adaptations for gas exchange?
A
They have a small surface area to volume ratio and live in water with less oxygen
21
Q
True or False: Respiration is the movement of air in and out of the lungs.
A
False
22
Q
What is the difference between breathing and respiration?
A
Breathing is air movement; respiration is a chemical reaction releasing energy (ATP)
23
Q
What is the primary gas exchange surface for fish?
A
Gills
Fish obtain oxygen from water using gills, which are adapted for efficient gas exchange.
24
Q
How much less oxygen is dissolved in water compared to the atmosphere?
A
30 times less
This requires fish to have adaptations to maintain diffusion and concentration gradients.
25
What are the three essential features of gas exchange surfaces?
* Large surface area compared to volume
* Short diffusion distance
* Mechanism to maintain concentration gradients
26
What is the formula for calculating the rate of diffusion?
Diffusion is proportional to (surface area * difference in concentration) / length of diffusion pathway
27
What anatomical structures create a large surface area in fish gills?
Gill filaments and gill lamellae
## Footnote
The numerous gill lamellae positioned at right angles to the filaments enhance the surface area.
28
How does water flow over fish gills to facilitate gas exchange?
Water flows over the gills in the opposite direction to blood flow
## Footnote
This is known as the counter-current flow mechanism.
29
What is the advantage of the counter-current flow mechanism in fish gills?
It prevents equilibrium of oxygen concentration, allowing continuous diffusion
## Footnote
This ensures that oxygen can always diffuse from water into blood.
30
What are the main gas exchange structures in leaves?
* Palisade mesophyll
* Spongy mesophyll
* Stomata
31
What is the role of stomata in gas exchange in leaves?
Oxygen diffuses out and carbon dioxide diffuses in
## Footnote
Stomata open during the day and close at night to minimize water loss.
32
What adaptations do xerophytic plants have to minimize water loss?
* Rolled leaves
* Deep sunken stomata
* Tiny hairs on leaves
* Thicker cuticle
* Longer root network
33
What is the purpose of bile salts in lipid digestion?
They emulsify lipids to form micelles
## Footnote
This increases the surface area available for lipase action.
34
What are the three types of enzymes involved in protein digestion?
* Endopeptidases
* Exopeptidases
* Dipeptidases
35
Where does carbohydrate digestion begin?
In the mouth
## Footnote
It continues in the duodenum and is completed in the ileum.
36
What type of transport is used for the absorption of monosaccharides like glucose?
Active transport via co-transport
## Footnote
This is due to the higher concentration of glucose in epithelial cells.
37
What is hemoglobin and its primary function?
A quaternary structure protein involved in mass transport of oxygen
## Footnote
Hemoglobin consists of four polypeptide chains.
38
What is the oxyhemoglobin dissociation curve used for?
To analyze how hemoglobin behaves under different oxygen partial pressures
39
What effect does a high partial pressure of carbon dioxide have on hemoglobin?
It shifts the oxyhemoglobin dissociation curve to the right
## Footnote
This decreases hemoglobin's affinity for oxygen.
40
What happens to hemoglobin's shape when the first oxygen binds?
It changes shape, facilitating the binding of additional oxygen
## Footnote
This is known as cooperative binding.
41
What effect does a lower pH have on hemoglobin's affinity for oxygen?
It decreases hemoglobin's affinity for oxygen, causing it to unload oxygen more readily
## Footnote
This is known as the Bohr effect.
42
What is the Bohr effect?
It is the phenomenon where hemoglobin's oxygen unloading increases as carbon dioxide levels rise and pH decreases.
43
What is the significance of fetal hemoglobin compared to adult hemoglobin?
Fetal hemoglobin has a higher affinity for oxygen, allowing it to extract oxygen from maternal blood.
44
How does llama hemoglobin adapt to high altitudes?
Llama hemoglobin has a higher affinity for oxygen at lower partial pressures.
45
What is the primary function of hemoglobin in doves?
Dove hemoglobin is adapted for high oxygen demand due to their flying, resulting in lower affinity for oxygen.
46
What type of circulatory system do mammals have?
Mammals have a closed and double circulatory system.
47
What does a double circulatory system imply?
Blood passes through the heart twice in each circuit—once to the lungs and once to the rest of the body.
48
What is the function of coronary arteries?
They supply the heart muscle with oxygenated blood.
49
List the four key blood vessels associated with the heart.
* Vena cava
* Aorta
* Pulmonary artery
* Pulmonary vein
50
What is the role of the pulmonary arteries?
They carry deoxygenated blood from the heart to the lungs.
51
What is the role of the pulmonary veins?
They carry oxygenated blood from the lungs back to the heart.
52
What does the term 'renal' refer to in blood vessels?
It refers to blood vessels attached to the kidneys.
53
Describe the unique properties of cardiac muscle.
* Myogenic
* Never fatigues
* Requires a constant supply of oxygen and glucose
54
What happens if a coronary artery gets blocked?
It can cause a myocardial infarction (heart attack) due to lack of oxygen and glucose to the cardiac muscle.
55
What are the two types of heart valves?
* Semilunar valves
* Atrioventricular valves
56
What is the function of heart valves?
To prevent the backflow of blood.
57
What separates the deoxygenated and oxygenated blood in the heart?
The septum.
58
What is the primary function of capillaries?
To facilitate the exchange of materials between blood and cells.
59
What is the structure of capillaries?
They are one cell thick to minimize diffusion distance.
60
What is the cardiac cycle composed of?
* Diastole
* Atrial systole
* Ventricular systole
61
What occurs during diastole?
The atria and ventricles are relaxed, allowing blood to enter the atria.
62
What happens during atrial systole?
The atrial muscles contract, increasing pressure and pushing blood into the ventricles.
63
What is the role of the ventricles?
To pump blood out of the heart at high pressure.
64
Why do arteries have thicker walls than veins?
To withstand higher pressure and allow for constriction and dilation.
65
What is the primary function of veins?
To carry deoxygenated blood back to the heart.
66
What aids in preventing backflow in veins?
Valves.
67
What is the difference between arteries and arterioles?
Arterioles are smaller and connect arteries to capillaries.
68
What is the diameter of capillaries compared to arteries?
Capillaries are very narrow in diameter.
69
What causes an increase in pressure in the Atria?
Blood entering the Atria through the vena cava and pulmonary vein increases the volume of liquid in the Atria
## Footnote
This increase in volume leads to atrial systole, where the Atria muscles contract.
70
What is the role of atrioventricular valves during atrial systole?
The atrioventricular valves open, allowing blood to move from the Atria into the ventricles.
71
What occurs during ventricular diastole?
The ventricle muscles are relaxed.
72
What happens during ventricular systole?
The ventricle muscles contract, increasing pressure above that of the Atria and causing the atrioventricular valves to shut.
73
What triggers the opening of the semilunar valves?
Increased pressure in the ventricles beyond that of the Atria and pulmonary artery.
74
How is cardiac output calculated?
Cardiac output = heart rate × stroke volume.
75
Define stroke volume.
The volume of blood that leaves the heart with each beat.
76
What is tissue fluid?
A fluid containing water, glucose, amino acids, fatty acids, ions, and oxygen that bathes the cells.
77
What process forms tissue fluid?
Ultrafiltration, where high hydrostatic pressure forces water and small molecules out of capillaries.
78
What cannot pass through the capillary walls?
Red blood cells, platelets, and large proteins.
79
What happens at the venous end of the capillary?
The hydrostatic pressure decreases, allowing water to re-enter the capillary by osmosis.
80
What is the role of the lymphatic system?
To transport excess liquid that is not reabsorbed back into the blood.
81
What is transpiration?
The loss of water vapor from the stomata of leaves.
82
List the four key factors that affect the rate of transpiration.
* Light intensity
* Temperature
* Humidity
* Wind
83
What is cohesion in the context of water movement in plants?
The sticking together of water molecules due to hydrogen bonding.
84
What is adhesion in the context of xylem?
The sticking of water molecules to the walls of the xylem.
85
Define root pressure.
The positive pressure created as water moves into the roots by osmosis.
86
What is the cohesion-tension theory?
The theory explaining how water moves up the plant against gravity due to cohesion, adhesion, and root pressure.
87
What are the two key cell types in phloem tissue?
* Sieve tube elements
* Companion cells
88
What is the function of companion cells in phloem?
To provide ATP for active transport of organic substances.
89
What is the source-sink model in phloem transport?
A model explaining how sugars produced in photosynthesis (source) are transported to respiring cells (sink).
90
How does sucrose affect water potential in source cells?
It lowers the water potential, causing surrounding water to enter the cells by osmosis.
91
What happens to water in the sink cells?
Water leaves the sink cells by osmosis, increasing hydrostatic pressure in the source cells.
92
What is the process of translocation in phloem?
The movement of sugars from source cells to sink cells driven by pressure differences.
93
What is the co-transport mechanism in phloem?
The simultaneous transport of sucrose with protons into sieve tube elements via a co-transporter protein.
94
What occurs when sucrose enters the sieve tube elements?
It lowers the water potential, causing water to enter from the xylem and increasing hydrostatic pressure.
95
What happens to sucrose at the sink?
It is used in respiration or stored, affecting water potential and causing water to leave the sieve tube elements.
96
What is the process by which water moves from the sieve tube elements into the zinc cell?
Osmosis
## Footnote
Water moves due to osmotic pressure differences.
97
What effect does the removal of water from the sieve tube element have on hydrostatic pressure?
Decreases hydrostatic pressure
## Footnote
This is due to the decrease in volume in the sieve tube element.
98
What drives the movement of soluble organic substances in the sieve tube element?
Difference in hydrostatic pressure between source and sink
## Footnote
This difference facilitates translocation.
99
What is the name of the investigation that uses radioactively labeled carbon to prove translocation?
Traces
## Footnote
Involves providing plants with radioactive carbon dioxide.
100
How do plants utilize radioactively labeled carbon during the traces investigation?
Absorbed through stomata and used in photosynthesis
## Footnote
Organic substances created will contain the radioactive label.
101
What happens to the x-ray film when it is exposed to sections of the stem containing sugars?
Turns black
## Footnote
This indicates the presence of sugars and highlights the location of phloem.
102
What is the outcome of the ringing experiment on a plant trunk?
Trunk swells above the removed section
## Footnote
Indicates that sugars cannot be transported when phloem is removed.
103
What analysis is performed on the liquid from the swelling in the ringing experiment?
Analysis shows it contains sugar
## Footnote
Confirms that phloem is responsible for sugar transport.
104
Fill in the blank: The removal of the phloem in the ringing experiment demonstrates that _______ cannot be transported.
Sugars
## Footnote
This illustrates the role of phloem in translocation.
