4 - Exchange and Transport Flashcards
1
Q
Define metabolic rate
A
Rate of chemical reactions in an organism over time
2
Q
Define exchange
A
Expel a substance and receive another
3
Q
Define facilitate
A
To make an action
4
Q
How to calculate surface area?
A
Length x length x number of sides cm2
5
Q
How to calculate volume?
A
Width x height x length cm3
6
Q
How to calculate Surface area : Volume
A
SA/V
7
Q
How to calculate area of a cirlce
A
𝜋𝑟^2 cm2
8
Q
How to calculate SA of a sphere
A
4𝜋𝑟^2
9
Q
How to calculate volume of a sphere
A
(4𝜋𝑟^3)/3
10
Q
How to calculate SA of a cylinder
A
𝜋ⅆℎ+2𝜋𝑟^2
11
Q
How to volume SA of a cylinder
A
𝜋r^2 ℎ
12
Q
4 common features of efficient gas exchange
A
Simple diffusion
Moist surface
Thin and permeable
Big SA
13
Q
Why does a moist surface lead to efficient gas exchange
A
Oxygen dissolves in the water
14
Q
What is Flick’s Law?
A
Rate of diffusion = surface area x con. difference
——————————————
thickness of membrane
15
Q
What are the holes in insects called?
A
Spiracles
16
Q
What are spiracles controlled by?
A
Valves
17
Q
Why can’t the spiracles stay open all the time?
A
When open, there is water loss
18
Q
Describe the tracheal system in insects (4)
A
1 - Air moves into trachea through spiracles
2 - O2 travels down conc. gradient towards cells
3 - Trachea branches off into tracheoles so O2 diffuses directly into body cells
4 - CO2 from cells moves down con. towards spiracles (released into atmosphere
19
Q
What does the tissue of insects contain?
A
A fluid that diffuses the hypotonic cytoplasm of resting cells
20
Q
What happens if lactic acid is produced in the tracheal system in insects?
A
Reduces osmotic potential so fluid is withdrawn from tracheoles
21
Q
How is air moved in larger insects?
A
Abdominal pumping
22
Q
Fish have a …………… metabolic rate
A
High
23
Q
What is the operculum?
A
Flap that protects the gills
24
Q
What colour is oxygenated blood in diagrams?
A
Red
25
What colour is deoxygenated blood in diagrams?
Blue
26
What is a gill arch
Tube that connects to the gill fillaments
27
What are gill filaments?
```
Attached to gill arch. Increase SA
I--------------------------
I______________
I
I-----------------------------
I-----------------------------
I------------------------------
I------------------------------
I
```
28
What are lamellae?
Lots of capillaries on top of filaments to increase SA
29
What are the two types of flow?
Parallel and counter-current
30
Graph for parallel flow
```
I \
I \
I \
I \__________________
I /--------
I /
I /
I /
_____________________________
```
Click on edit to see graph
31
Graph for counter-current flow
```
\\
\\
\\
\\
\\
```
32
Describe counter-current flow (5)
Blood and water flow are in opposite directions
Water always has a higher oxygen concentration than blood in gill capillaries
Oxygen diffuses into gill capillaries across entire length of lamellae
Gills absorb ~80% oxygen from water across gills
Equilibrium is never reached
33
What is the buccal cavity?
The mouth of the fish
34
What is inspiration in fish? (6)
```
Mouth opens
Operculum valve closes
Buccal chamber lowers
Volume increases
Pressure decreases
Water flow into mouth
```
35
What is expiration in fish? (6)
```
Mouth closes
Operculum valve opens
Buccal chamber raises
Volume of cavity decreases
Pressure inside increases
Water flows over gills
```
36
Limitations of tracheal system (2)
Relies on diffusion
| Limit insect size
37
5 ways to increase exchange effectiveness in insects
```
BIG SA
Steep conc. gradient
Continual flow
Short pathway
Abdominal pumping
```
38
2 reasons why we need lots of gas to exhcnage
High metabolic rate
High respiratory rate
So we need to maintain out temperature
39
Do humans have a high or low SA:V
Low
40
Why are our lungs inside our body? (2)
Body would lose H2O as surfaces are moist
Air isn't dense enough to support and protect
41
Name the body parts that are involved in respiration (in order)
```
Lungs / mouth
Trachea
Bronchi
Bronchioles
Alveoli
```
42
Where does air enter in people?
Mouth or nose
43
Why is it preferred for air to enter through our nose? (3)
Warm and lined with capillaries
Moist and secretes mucus
Contains hairs to filter
44
What shaped are the rings on the trachea? Why?
C- shaped.
| Provide strength but still flexible
45
What is the trachea lined with? Why?
Cilia - beat upwards to secrete mucus. Prevent foreign bacteria from entering lungs
46
What is the pharynx?
Where trachea and oesophagus meet behind mouth
47
What are the bronchi and bronchioles?
Each bronchus enters a lung and divides into bronchioles
48
4 adaptations of alveoli
1 cell thick - short pathway
600 million - high SA:V
Next to capillaries (maintain conc. grad)
Moist - O2 dissolved
49
What are epithelial cells?
Cells that are in contact with the external environment
50
What are endothelial cells?
Cells that are NOT in contact with the external environment
51
What type of cells are in contact with the external environment?
Epithelial
52
What type of cells are NOT in contact with the external environment?
Endothelial
53
Where does gas exchange happen in humans?
Alveoli walls
54
What are the two things are involved in the mechanisms of breathing?
Diaphragm
| Intercostals muscles
55
What does the intercostals muscles do?
Move ribs up and down
56
Describe the process of inhalation in humans (5)
1. Intercostals muscles contract and move up
2. Diaphragm contracts and flattens
3. Chest cavity increases so volume increases
4. Internal pressure of air in lungs reduces
5. Outside air flows into lungs
57
Describe the process of exhalation in humans (5)
1. Intercostals muscles relax
2. Diaphragm relax and return to arc position
3. Volume reduces
4. Pressure increases
5. Air forces outside of lungs
58
3 ways insects reduce water loss
Small SA:V
Waterproof coating
Spiracles
59
2 ways plants reduce water loss
Close stomata
| Waterproof cotaing
60
Why can't plants have a small SA:V
Needed for photosynthesis
61
What is a xerophyte?
Plant adapted to having a low water supply
62
What type of plants are adapted to having a low water supply?
Xerophyte
63
4 adaptations of plants reducing water loss
Thick cuticle
Roll up leaves
Hairy leaves
Small SA:V on leaves
64
Why do leaves roll up and how?
Reduce water loss - protects lower epidermis and traps air so no concentration gradient
65
Why are leaves hairy?
Trap moist air to reduce concentration gradient
66
Define stomata
Pores mainly found on underside of leaf. Surrounded by guard cells
67
Where are stomata mainly found?
Underside of leaf
68
What do the stomata do?
Control rate of gas exchange to minimise water loss
69
Where does deoxygenated blood go? (4)
Vena cava
Right atrium
Right ventricle
Pulmonary valve then artery
70
Where does oxygenated blood go? (4)
Enter through pulmonary vein
Left atrium
Left ventricle
Aortic valve then aorta
71
Atrium associated with deoxygenated blood
Right
72
Atrium associated with oxygenated blood
Left
73
Artery associated with deoxygenated blood
Pulmonary
74
Valve associated with oxygenated blood
Aorta
75
Describe the process of digesting lipids (5)
1. Emulsification of fat droplets
2. Micelle formation
3. Micelle breakdown when in contact with epithelial cells, releasing FA and monoglycerides
4. Triglyceride combines with cholesterol and lipoproteins to form chylomicrons
5. Chylomicrons move out of cell by exocytosis and enter lacteals
76
What are chylomicrons?
Triglyceride combines with cholesterol and lipoproteins
77
Describe the co-transport of Na, glucose and K (5)
1. Sodium moves from epithelial cells into blood by active transport
2. Reduce sodium conc. in cell
3. Sodium diffuses into the cell by diffusion
4. Symporter protein used as AA can also be transported
5. Glucose does facilitated diffusion into blood
78
Define peristalsis
Moves food down the oesophagus
79
What is the alimentary canal?
Passage from mouth to anus
80
What are lacteals?
Lymphatic vesicles found in the centre of the villi
81
What is a lumen?
Hollow part of something
82
What are micelles?
Emulsified fat droplets
83
Define exocytosis
Move out of a cell
84
What is the ileum?
Small intestine
85
What is the colon?
Large intestine
86
Define hydrolysis
Chemical breakdown of a compound with water
87
Define assimilate
Nutrients in food are taken into the cells of the body
88
Define emulsification
Breakdown of fats into smaller molecules to provide a bigger SA
89
What happens during the emulsification of lipids
Triglyceride is added to lipase to form a monoglyceride and two FA
Ester bond hydrolyses
90
What type of digestion happens at each stage of the digestive cycle?
```
Mouth - mechanical and chemical
Oesophagus
Stomach - mechanical and chemical
S.Intetsine - chemical
L.intesine
```
91
Where does ingestion happen
Mouth
92
Where does egestion happen?
Rectum and anus
93
Two parts of the small intestine
Duodenum and ileum
94
What is the right spelling: ilium or ileum?
Ileum
95
What happens in the duodenum?
Pancreatic juices and bile is released
96
What happens in the ileum?
Main site of absorption
97
2 examples of physical digestion
Teeth and muscles (churning)
98
What is chemical digestion?
Hydrolyse large, insoluble molecules by enzymes
99
Process of digesting carbohydrates (4)
1. Amylase hydrolyses glyosidic bond of starch
2. Maltose is produced
3. Maltase hydrolysis A1-4 glyosidic bond of maltose
4. Alpha glucose is produces
100
Process of digestion (6)
1. Salvia mixed with food, which contain salivary enzymes
2. Starch goes into maltose
3. Food enters stomach and sal. enz. are denatures
4. Go to ileum to ix with pancreatic juices
5. Peristalsis happens
6. Maltase released so maltose goes into glucose
101
3 ways to digest proteins
Endopeptidases
Exopeptidases
Dipeptidases
102
What is endopeptidases?
Hydrolysis peptide bond in AA central region
103
What is exopeptidases?
Hydrolysis bond on terminal AA (end of AA)
104
What is dipeptidases?
Hydrolyse the bond between the two AA of a dipeptide.
105
4 adaptations for absorption
Villi contracts so epithelial cells are in contact with food
Microvilli increase SA
Capillary network to maintain conc. grad
Lacteal - fats are absorbed
106
Define digestion
Break down of large, insoluble food molecules into smaller, soluble ones that can be absorbed into the small intestine
107
What is the vein rich in?
Nutrients
108
What is the artery rich in?
Oxygen
