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exchange and digestion Flashcards

1
Q

where in a cell has highest CO2 conc and lowest O2 conc and why

A

mitrochondria
to maintain diffusion gradient

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2
Q

why do small and inactive organisms not require specialised gas exchange surfaces

A

they have a low surface area to volume ratio
so gas can exchange across a thin membrane

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3
Q

why do large organisms require a circulatory system

A

because of their large surface area to volume ratio

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4
Q

why do specialised exchange surfaces have large surface area to volume ratio

A

increases rate of exchange

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5
Q

why do specialised exchange surfaces have very thin membranes

A

to decreases diffusion pathway

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6
Q

why do specialised exchange surfaces have selectively permeable membrane

A

allows only certain materials across

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7
Q

why do specialised exchange surfaces have movement of environmental medium in them

A

maintain diffusion gradient

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8
Q

why do specialised exchange surfaces have movement of internal medium

A

maintain diffusion gradient

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9
Q

what is ficks law

A

diffusion = SA x conc difference /length of pathway

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10
Q

describe the relationship between size of microorganism and SA;V

A

as the size of something increases the surface area to volume ratio decreases

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11
Q

what are the two ways terrestrial insects prevent water loss

A

exchange system has a small surface area to volume ratio
waterproof covering on exposed exoskeleton

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12
Q

name the parts of an insects tracheal system

A

spiracle
trachea
muscle tissue
tracheoles

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13
Q

what happens when insects respire anaerobically

A

lactic acid is produced which is solute and lowers the water potential of water in the tracheoles
the water is then moved via osmosis from trachea to cells.
air is drawn into tracheoles creating a lower pressure to increase rate of diffusion because muscle cells are swollen so closer to tracheoles

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14
Q

how are spiracles adapted to help maintain humidity

A

body segments pull skeleton plates together
air squeezes into the sacs to limit gas exchange

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15
Q

how are spiracle hairs used to reduce water loss

A

trap water molecules which maintains the hummidity around the spiracles to reduce conc gradient so less water is lost

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16
Q

what is the function of chitin in the trachea
also what is chitin

A

nitrogen containing polysaccharide
maintain trachea shape even at low pressure

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17
Q

name the parts of a fish gill

A

gill arch
gill
operculum
operculum opening
gilll filament
lamella

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18
Q

how do fish get oxygen from the water/
describe its structure

A

water is taken in the through the mouth and passed over the gills and out the operculum
gills comprise of filaments which increase the surface area
on the fillaments are lamella which also increase surface area
counter current flow - oxygen and water flow in opposite directions to maintain conc gradient

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19
Q

why do fish die in air

A

lamella stick together in air so decrease surface area and gas exchange cant happen so quick

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20
Q

by what process does water move out of the stoma

A

diffusion

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21
Q

what are stoma

A

pores on the underside of leaves which are surrounded by guard cells which control their opening and closing

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22
Q

what are the guard cells when stoma is open

A

turgid

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23
Q

what are the guard cells when stoma is closed

A

plasmalised
because water moves down water potential gradient and into the mesophyll

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24
Q

how do plants prevent water loss

A

closing the stoma
waterproof cuticle on leaves
rolling up leaves creates a high water potential so does hairs on leaves
reduced SA:V (pines)

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25
name the parts of the human exchange system
nasal cavity trachea bronchi bronchiole alvioli capillaries
26
why do humans need to respire aerobically
to have regular supplies of oxygen to make ATP during respsiration in the mitrochondira which also produces CO2 as a waste product
27
describe the specific qualities of the trachea
C shaped rings of cartalige ciliated epithelial cells which waft rythmically smooth muscle cells elastic tissue
28
describe the specific qualities of the bronchus
small sections of cartalige ciliated epithelial cells which waft rythmically smooth muscle cells elastic tissue
29
describe the specific qualities of the bronchioles
ciliated epithelial cells which waft rythmically smooth muscle cells - contract t control air movement in the lungs elastic tissue
30
describe the specific qualities of the alvioli
squaremous epithelial cell elastic tissue - allows them to stretch and fill with air
31
what is the difference between bronchioles and bronchus by appearance
bronchioles have rough felled inner surface whereas bronchus are less likely to and will have chunks of cartilage
32
in what direction does gas move
from an area of high pressure to low pressure
33
what is inspiration
air pressure inside the lungs is reduced so air moves in
34
what is expiration
air pressure inside lungs is increased so air moves out
35
describe the steps of inspiration
1. external intercostal muscles contract 2. internal intercostal muscles relax 3. ribs and sternum move up and out 4. diaphragm contacts and flattens 5. volume of thorax increases 6. elastic tissue of lungs os streched 7. lunges expand 8. pressure in lungs is reduced 9. air is forced into alvioli
36
describe the steps of expiration
1.external intercostal muscles relax 2. internal intercostal muscles contract 3. ribs and sternum move down and in 4. diaphragm relaxes and returns to dom shpe 5. volume of thorax decreases 6. elastic tissue recoils 7. lung size decreases 8. pressure inside the lungs increases 9. air is forced out of the alvioli
37
what is pulmonary ventilation
volume of air moved into the lungs in one minute
38
what is ventilation rate
number of breaths in one minute
39
what is tidal volume
resting breathing rate
40
what is vital capacity
max inhale + max exhale
41
what is the formula for pulmonary ventilation
tidal volume / ventilation rate
42
what is the formula for cardiac output
stroke volume ( volume of blood per beat) x heart rate
43
how does large surface area influence rate of gas exchange in the lungs
large area for diffusion so is quicker
44
how does very thin walls influence rate of gas exchange in the lungs
short diffusion pathway so is quicker
45
how does movement of medium influence rate of gas exchange in the lungs
maintain diffusion gradient more movement = more diffusion
46
how many cells does a gas cross from alvioli to lungs
2 epithelial of alveoli and capillary
47
what does the line in a spirometer mean
down = inhale up = exhale
48
what does the line in a lung capacity graph mean
down = exhale up = inhale
49
what are the symptoms of pulmonary fibrosis
chronic dry cough pain in chest short breath weakness/fatigue
50
what are the causes of pulmonary fibrosis
pollutants ( common among minners) ideopathic - unknown cause
51
what is pulmonary fibrosis
scar tissue in the lungs causing less diffusion and less elasticity which causes difficulty breathing because alvioli cant recoil or fully inflate
52
what are the symptoms of asthma
tight chest difficulty breathing wheezing coughing
53
what are the causes of asthma
family history allergens ( fur , cold air , anxiety)
54
what is asthma
inflamation of the linng of the bronchi more mucus is produced so there is a resistance to air flow and oxygen conc decreases so less diffuses into the blood
55
what are the symptoms of emphysema
short breath chronic cough bluish skin colour
56
what are the causes of emphysema
smoking
57
what is emphysema
damage to elastin proteins ins the lungs so they loose elasticity so cant force air out or in so decreases diffusion into blood diffusion pathway is increased because walls of alvioli are broken down
58
what are the risk factors for COPD
smoking air pollution genetics frequent infections occupation
59
what is a casual link in data
direct cause and effect relationship
60
what are the 3 stages of the scientific process
establish hypothesis design and perform experiments establish casual link and formulate theories to explain this
61
why do lipids lubricate the lungs
prevent alvioli being stuck together after a large inhalation
62
how does the digestive system work
glands produce enzymes that hydrolyse macromolecules into simple molecules ready for absorption
63
why are your intestines not technically part of your body
molecules and ions only truley enter your body when they are absorbed in the epithelial cells your intestines are an outside environment
64
what does the salivary gland do
secret amylase via a duct to the mouth which catalyses the hydrolysis of starch into maltose
65
what does the oesophagus do
carries food from the mouth to the stomach made up of thick muscular walls
66
what does the stomach do
inner layer produces enzymes stores and digests food especially proteins glands produce digestive proteins other glands produce mucus which prevents self digestion of its own enzymes
67
what does the pancreas do
a large gland below the stomach secrets protease to digest proteins lipase to digest lipids and amylase for the hydrolysis of starch
68
what does the small intestine do
long muscular tubes where food is digested inner walls are folded into villi for large SA and covered in micro villi absorbs products into the bloodstream
69
what does the large intestine do
reabsorbs water food becomes thicker and drier making faeces
70
what does the rectum do
faeces is stored here before being removed via egestion
71
what is absorption
moving soluble molecules into the cell from the small intestine
72
what is assimilation
absorbed amino acids that are used to make new proteins
73
what is physical breakdown
breaking large food into smaller foods via chewing and muscular contractions in the stomach to increase SA
74
what is chemical breakdown
using enzymes to hydrolyse molecules
75
name 2 membrane bound enzymes
sucrase and lactase
76
summaries starch digestion
amylase from salivary gland and pancreas not membrane bound makes maltose
77
summaries maltose digestion
maltase from the ileum membrane bound makes alpha glucose
78
summaries sucrose digestion
sucrase from the small intestine membrane bound makes alpha glucose and fructose
79
summaries lactose digestion
lactase from the ileum membrane bound makes alpha glucose and galactose
80
summaries proteins digestion
endopeptidase - from the pancreas- not membrane bound - makes amino acids exopeptidase - from pancreas - not membrane bound - makes amino acids dipeptidase - from the ileum - membrane bound - amino acids
81
summaries lipids digestion
lipase from pancreas not membrane bound glycerol +fatty acid (monoglyceride)
82
what is the role of bile salts in lipid digestion
emulsifies large fat droplets into small ones
83
what is lactose intolerance
when your body doesn't digest lactose because it cannot produce lactase
84
why does lactose intolerance lead to diarrhea
because solutes have not been absorbed are in the faeces so the water potential is lower so cannot be drawn out in the large intestine
85
How are amino acids absorbed into the blood stream
Co transport from ileum to epithelial cell Facilitated diffusion through carrier proteins from epithelial cell to blood stream
86
Steps of Lipid digestion
1 bile salts produced in the liver emulsify lipids into Micelles to increase surface area 2ester bonds in the triglycerides are hydrolysed by pancreatic lipase the fatty acids and monoglycerides produced are packaged into micelles 3micelles come into contact with epithelial cells of villi and release monoglycerides and fatty acids 4they diffuse into epithelial cells and move towards the endoplasmic reticulum where they form triglycerides 5 these triglycerides in the chlymicrons are hydrolysed and fatty acids diffuse into tissue 6 they move out of epithelial cell via exocytosis and into lacteals 7chlyomicrons move from lacteals into blood stream
87
Are chlycomircons water soluble
Yes they can pass from lacteals to capillaries
88
Describe carbohydrate digestion
1 saliva enters mouth from salivary gland and mixes with food during chewing 2 hydrolysis of glycosidic bonds in starch by amalayse to form maltose 3 food is swallowed and enters the stomach 4 food moves to ileum where is mixes with pancreatic amylase 5 pancreatic amylase continues hydrolysis of starch to maltose 6 epithelial lining of the ileum produces the disaccharide maltase Which is membrane bound and hydrolysed maltose into alpha glucose 7molcules are absorbed via co transport of sodium

biology (29 decks)

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