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biology > topic 3 - organisms exchange substances with their environment > Flashcards

topic 3 - organisms exchange substances with their environment Flashcards

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1
Q

small organisms have a _ surface area to volume ration

A

very large
big surface for ecashnge of substances
so small orgnsisms can simpy exchange susbstances across their surface

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2
Q

larger organisms have a _ surface to volume ratio

A

small
much large distasnce from the middle to the outisde
typically have a bigger metabolic rate

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3
Q

what is beasthing

A

the movement of air into and out of the lungs

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4
Q

what is ventilation

A

scientific term for breathing

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5
Q

what is respiration

A

chemical reaction to relase energy in the form of atp

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6
Q

what is gasseous exchange

A

diffusion of oxygen from the air in the alveoli into the blood and of carbon diozide from the bllod into the air in the alveoli

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7
Q

ventilation involves…

A

diaphram
antaganositc interaction betwen the extenral and internal intercostal muscles

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8
Q

inspirartion process:

A

extenrla intercostal muscles - contract pulling ribs up and out
internasl intercostal muscles - relax
diaphram - contracts to move down and flasttens
air pressure in lungs - instranly drops as air moves in it rises above atmpshperic pressure
lung volume - increases
mocement of air - into lungs

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9
Q

expiration process

A

extenral intercorstasl mucles - relax
internal - contract pulling ribds down and in
diaphram - relaxes and mvoed up into a dome shape
air pressure in lungs - intnially grater than atmpspheric pressure drops as air moves out
lung volume decreases
air mvoes out

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10
Q

what is pulmanory ventilation

A

the total voume of air moved into the lings in one minute

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11
Q

how do we calculate pulmiary ventilation

A

tidal volume x ventiatoin rate

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12
Q

adaptations of alveoli

A

300 million tiny air sacs in each lungs - large surface area for gas exchange
epithelium cells very thin - minimise diffusion distance
neotwork of capilaries surrounding each alveolus - maintain conc gradient

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13
Q

what are spiracles

A

round valve like openings along the length of the abdomem

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14
Q

trachea what is

A

network of internal tubes, the teache tubes have rings within them to strengthen tubes and keep them open

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15
Q

tracholes what are

A

teachea branch into them
they extend throught all tissues in the insect to deliver oxygen to all resporing cells

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16
Q

adaptations for efficient diffusion - insects

A
  • large numebr of fine tracheoles - large surface area
  • walls of teaches anre thin and short distnce between spiracles and tracheoles - short diffusion pathway
    use of oxygen and producion of co2 - steep difusion gradients
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17
Q

3 methods of moving gasses in the teacheal system:

A

diffusion - when cells repisre they use up oxygen and produce co2 creating conc graident from tracheoles to the atmosphere
mass transport - contracts and relaxes abdominal muscles to move gasses on mass
repire anaerobially - produce lactate, this lowers the water potential of the cvells and water moves from the teacheoles into the cells by osmosis, this decreases the volume of air int he teacheoles and more air from the atmpsphere is drawn in

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17
Q

3 insect adaptations to prevent water loss

A
  1. small surfave area to volume ration where water can evaporate from
  2. waterproff expsceleton
  3. spiracles, gasses enter and water can evaporate from, can open and close to reduce water loss
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17
Q

fish - 3 adaptions for efficient gas exvhanfe

A

large surface to volume ration - created by many gill filaments covered in many gil lameli
short diffusion pathway - capilary network in every lameli and very thin gil lameli
maintaining conc graidet - counter current flow mechanism

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18
Q

why do fish have to maintan a conc gradient to enable diffusion to occur?

A

30x less oxygen in the water than air

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19
Q

how can the rate of diffusion be calculated?

A

ficks law
( surface area x difference in concentration ) / length of difusion path

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19
Q

how does the counter current flow mechanism work?

A

water flows over gills in opisite direction to direction of blood flow in the capilaries
this ensures equilibrium is not reached
emsures the difusion gradient is maintrianed across the entire length of the gil lameli

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20
Q

what are xerophytic plants

A

thes epaknts are addapted to survive in pantsa with limited water suply

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21
Q

5 adaptations of xerophytes

A

trap moisture and mainstain local humidity:
- curled leaves
- hairs
- sunken stomata

reduce evaporation
- thicker cuticle

longer root netwrok to reach more water

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22
carbohydrates rewuire mroe than one enzyme to hydrolise them into monosacherides:
amalayse membrene bound disacheridases
23
amalayse produced in? hydrolises?
salivary glands hydrolisies into the disacheride maltose by hydrolising the glycosidic bonds
24
examples of membrene bound disacheridases and what do they break down?
sucrase and lactase - examples into lactose and sucrose
25
protiens can by hydrolised by three enzymes:
1. endopeptidases - hydrolise peptide bonds betwene amino acids in the midle of the plypeptide chain 2. exopeptidases - hydrolise peptide bonds between amino acids at the end of the polypeptide chain 3. membrene bound dipeptidases - hydrolise peptide bonds between two amino acids
26
digesting lipids inviolves two stages:
physical and chemical
27
outline physical stage of lipid digestion
lipids are coated in bile salts to creat an emulsion many small droplets of lipids provide a large surface area to enable faster hydrolysis by lipase
28
outline chemical stage of lipid digestion
lipase hydrolises lipids into glycerol and fatty acids
29
outline lipid absorbtion
lipids are digested into monoglycerides and fatty acdis by the action of bile salts and lipase these form tiny struictures called micelles when micelles encounter the ileum epithelial cells due to the non polar nature of fatty acids and monoglycerides they can simply difuse acrosss the cell surface membrene to enter the cells of the epithelial cells once in the cell these will be modified back into tryglycerides inside of the endoplasmic reticulum and golgi body
30
monosacheride and amino acid absorbtion
to absorb glucose and amino acids from the lumen to the gut there must be a higher conc in the lumen compred to the epithelial. cell ( for facilitiated diffusion ) but there is usually mroe in the epithelial cells this is why active and co transport are required
31
hameoglibin what is it
groupsof protiens found in different organisms protien with a quatenrary structure hameologin and red blood cells traposrt oxygen
32
oxygen is loaded in a region with...
a high aprtial pressure of oxygen
33
oxygen is unloaded in ...
regiions of low partial pressure of oxygen
34
explain the cooperative nature of oxugen binding ...
hameglobin change shsape when the first oxyugen binds this makes it easeir for further oxygens to bind
35
what is the bhor effect?
when high csrbon dioxide concentraoin causes oxyhaemoglobin curve to shift to the right the affinity for oxygen decresses becuase the acidic co2 changed the shape of the hameoglobin slightly
36
lower pareial rpessure of co2 in the alvoli causes shifts to the...
left, increased afinity therefore uploads more oxygen
37
high partial pressiure of co2 ar respoirng tissues causes shifts to the...
right decreased affninty and therefore unloads more oxygen
38
birds have a faster metabolism so...
need more oxugen for respoiration to provide enregy for contraticng muscles
39
what is a double closed circulatory system?
closed - the blood remians within the blood vesles double - the blood passes through the heart twice in each circuit there is one circut delivering blood to the lungs and anohter one delviering blood to the rest of the body
40
why do mamels reuure a double circulatory system to mamge the pressure of blood flow?
blood flows thorugh lungs at a lwoer pressure this prevents danage to the capilaires in the alveoli alsp reducing the speed at wich blood flows enableing time for gas exchange oxugenated blood pumped at a hgiher pressure t the rwest of the body, ensuring the blood reaches all the repsoring cells in the body
41
caridac muscle two unieuqe properties:
myogenic - can contract and relax withought producing a nervous or hormoal reponse will never fatuge. ( as long as it has a suply of o2 )
42
propterties of the atria
thin muscular walls do not need to contract as hard as not pumping blood far ( only to ventricles ) elastic walls to stretch as the blood enters
43
properties of the ventircles
thicker muslular walls to enable bigger contraction creats a higher blood pressure to enable blood to flow longer distances ( to the lungs and the rest of the body )
44
44
right ventricle structure
pumpls blood to lungs at a lower rpessure to prevent danage to the capilaires in the lungs - and so blood flows slowly allowing time for gas exchange thinner muscluar walls in the left ventricle
45
left ventricle structure
pumps blood to the body this needs to be at a higher pressure to ensure blood reaches all the cells in the body therefore thikcer musluar walls in coparison to the right ventricle to enable larger contration in muscles to creat higher pressure
46
semi lunar valves in...
aorta and pulmanory artery
47
atrioventricular valves
between atria and ventricles
48
how do valves work?
open when the pressure is higher behind the valve closes when the pressure is higher in front of the valve prevents backflow of blood
49
what is the job of the septum in the heart
this sepeared oxygenated and deoxugenated blood maintains high concentratoin of oxygen in ozygenated blood to mainstain concentration gradient to enable diffusion at resporing cells
50
artieries...
cary blood away from the heart into the atrioles
51
atrioles...
smaller than the arteries and connect to the capilairies
52
capiliairs...
connect arterioles to the veins
53
veins...
cary blood back into the heart
54
ateries - muscular layer
thicker than viens so that consitriction anfd dialation can occur to controll volume of blood
55
veins - muscular lauyer
reliitvely thin so it can not controll the blood flow
56
ateries - elastic layer
thickeer than viens to help maintain blood pressure the walls cans tretch and recoil in reponse to heart beat
57
veins - elastic layer
relitively thin as rpessure is much lower
58
arteries - wall thickness
thicker than viens to prevent vesels bursting due to the high pressure
59
wall thickness - viens
thin as pressure is much lower
60
capilaires have a narrow...
diametre to slow blood flow, red blood cells can jsut fit through and are squashed against the walls so this maximises diffusion
61
arterioles - muscilar layer
thicker than in arteries to help restirct blood flow into the capilaiires
62
arterioles - elastic layuer
thinnker than in the arteries as the pressure is lower
63
arterioles - wall thickness
thinner as pressure is slightly lower
64
3 stages of the cardiac cycle
diastole atrial systole ventricular systole
65
outline 1st stage if the cardiac cycle - diastole
the atria and ventricular muslces are relaxed this is when blood will enter the atria via the vena caval and pulmonory vien the blood flowing into the atria increases the pressure within the atria
66
outline second stage of the cariad cycle - atrial systole
atrial muscle will contract increasing the pressure further this causes the atrioventriular valurs to open and blood to flow to the ventricles
67
outline 3rd stage of the cariad cycle - ventricular systole
after short delay the ventricle muscluar walls contract icnreasing hte pressure btone that of the atria this causes the atrioventricular values to close and the semi lunar valeus to open the blood is then oushed out of the ventricles into the arteries
68
what is cardiac output
the volume of blood wich leaves one ventricle in one miute
69
how do we calculate cariad output
heart rate x stroke volume
70
what is tissue fluid
fluid containing water glucose amino acids fatty acids ion ozygen it bathes the tissues
71
how is tissue fluid formed?
capilaires have smapp gaps in the walls so liquid and small molecules can be forced out as blood enters the capilaires from the arterioles the smaller diametre reults in a high hydrostatic presusre so water, glucose, amino acids, fatty acids ions and oxygen are forced out this is known as ultrafiltration
72
tissue fluid ( what is forced out )
water disolved minerals and salt glucose small protiens and amino acids fatty acids oxygen
73
tissue fluid ( what remains in the capilary )
red blood cells, platelets large pritiens
74
how is tissue fluid reabsobed?
large molecules remain in the capilaires and creat a lowered water pottential towards the venule end of the capailaires the hydrostatic pressure is lowered due to the loss of liwueid but the water pottential is very low water re enters the capilaiired by osmosos
75
what is lymph
the rest of the tissue fluid is absorbed into the lymphatic systen and eventurlaly drains back into the blood stream into the heart
76
what is transpiration
the loss of watee vapour from the stomata by evaporatoin
77
light - factor affecting transpration
more light causes more stomata to be open - larger surface area for evaporation
78
temperature - factor effecting transpiration
positive corelation more heat means mrpoe keentic energy fasster moving molecules results in mroe evaporation
79
humidity - fsctor affecting transpratrion
negstvie correlation mroe water vapour in air will make the water pottentisl more positive outisde the lead therefore reduces the water potential gradient
80
wind - factor affecting transpiration
positive more wind blow away the humid air contianing water vapour therefore maintaining the water pottential gradient
81
why does cohesion work?
water is a dipolar molecule ( sligntly negative oxygen and skight positive hydrogens ) this enables hydrogen bonds to form between the hydrogen and oxygen of different water molecules this creats cohesion between molecules and they stick together thierefore water travels up the xylem as a continuous water column
82
what is capilarity
the adhesion of water when water sticks to other moelcules water adheards to the xylem cells the narower the xylem the bigger the impact of the capilarity
83
explain root pressure
warter moves into the roots by osmossi increases the volume of liquid indie the root therefore the pressure inside the root increases this icrease i pressure i the roots forces water above it upwards
84
outline movement of water up the xylem
water evaporates out of the stomata on leaves this loss of water volume creats a lower pressure when water is lsot by transpiration more water is pukled up the xymlem to replace it due to the hydrogen bonds between water molecules they are cohesive this creats a continuous column of water in the xylem warer molecyles ahead to the walls of the xylem this helps to pull the water column upwards
85
phloem tissue contains two key cells:
sieve tube elemnts companion cells

biology (5 decks)

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