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A level Biology > unit 3- updated > Flashcards

unit 3- updated Flashcards

1
Q

how do you work out surface area to volume ratio

A

1) to work out SA, (h x w) of one face X by number of sides
2)volume is w X h X l
3) divide them

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2
Q

how do single celled organisms exchange susbstances

A

single celled organisms have a higher surface area compared to their volume. this means that substances for example oxygen can directly diffuse into or out of the cell across the cell surface membrane.

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3
Q

how do multicellular organisms exchange susbtances

A

larger organims have a lower surface area in relation to their volume which means diffsuion would be too slow, they need specialised excahnge systems for example the lungs

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4
Q

mass transport in animals

A

circulatory system, which uses blood to carry oxygen glucose hormones co2 waste antibodies

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5
Q

mass transport in plants

A

xylem and phloem

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6
Q

body size and heat exchange

A

larger organisms have a smaller sa to volume ratio meaning that it is difficult to loose heat
smaller organisms have a larger surface area to volume ratio and loose heat easily, thats why they need a higher relative metabolic rate to keep warm

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7
Q

heat exchange and body shape

A

a less compact shape means that an organim has a higher surface area to volume ratio
a more compact shape means that an organism has larger surface area relative to volume this minimises heat loss

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8
Q

behavioural and physcological adaptasions to aid excghange is smaller orgasmins

A

animals with a larger surface area to volume ratio loose water more quickly as it evaporates from its surface this is a problem for animals living in hot regions, they had adapated kidney structure to produce less urine to compensate
in colder regions they have fur to keep warm

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8
Q

behavioural and physiological adaptations to aid exchange in larger organisms

A

larger organisms have a smaller surface area in relation to their volume this means that they find it difficult to loose heat. as an adapation they have developed large flat ears to increase surface area to keep cool

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9
Q

examples of adaptations to increase surface area and volume in plants and animals

A

-villi or microvilli to increase digestion absorption
-alveoli and tracheoles for gas exchange
-thin wide leaves
-many capillaries

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10
Q

why cant larger organisms use diffusion

A

diffusion would be too slow to supply its demand
!)cells are deep within the body, there is a large distances between the cells and outside environment
2)it has a lower surface area to volume ratio, meaning substances have to diffuse from a relatively small outer surface and a larger volume

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11
Q

what is the role of gas exchnage

A

to get oxygen in the blood for respiration and to get rid of carbon dioxide (waste)

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12
Q

what are the intercostal muscles

A

between the ribs
internal and external intercostal muscles

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13
Q

whats ventilation

A

the process of inhalation or exhilation

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14
Q

is inspiration an active or passive process

A

active process req. ATP

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15
Q

what does antagonistic mean

A

the intercostal muscle is moving in opposite directions

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16
Q

inspiration

A

external intercostal muscles and diaphragms contract
the ribcage moves up and outwards
the diaphragm flattens
lung pressure decreases below atmospheric pressure
volume of thoracic activity increases

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17
Q

is expiration an active or passive process

A

passive except if its forceful

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18
Q

expiration

A

internal intercostal msucels contrcat
diaphragm and external intercostal muscles relax
ribcage moves down and inwards
pressure increases above atmospheric pressure
volume in thoracic activity decreases

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19
Q

alveoli structure

A

one cell thick; alveolar epithelium
the alveolus contains a protein called elastin which allows recoil and return back to its normal shape after inhalation and exhalation

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20
Q

gas exchange in alveoli

A

oxygen moves through the alveoli into the alveolar epithelium into the capillary epithelium into haemoglobin

21
Q

factors effecting rate of diffusion

A

-thin, the alveoli are one cell thick
-large SA, millions of alveoli
-steep concentration gradient of oxygen and carbon dioxide between the alveoli and capiliries- faster diffusion

22
Q

tidal volume

A

volume of air in each breath

23
Q

ventilation rate

A

breaths per min

24
Q

forced expiatory volume

A

maximum volume of air that can be breathes out in one second

25
Q

forced vital capacity

A

the maximum volume of air it is possible to breathe forcefully out of the lungs after a really deep breathe in

26
Q

differences between healthy lung tissue and diseased lung tissue

A

scarred lung tissue which is thick and less elastic(fibrosis)

27
Q

the effect on lung diseases on gas exchange

A

all reduce the rate of gas exchange in the alveoli —> less oxygen is able diffuse into the bloodstream—->the body cells receive less oxygen—–> rate of respiration is reduced—>less energy is released—-
>weakness

28
Q

how do you calculate percentage change

A

Subtract the original value from the new value, then divide the result by the original value. Multiply the result by 100

29
Q

whats a spirometer

A

test to investigate lung function, and diagnose lung disease,
can figure out tidal volume and ventilation

30
Q

what tools do you for dissection

A

dissecting scissors, more precises cuts and less likley to snap under pressure
dissecting pin
dissecting scalpel
tweezors

31
Q

what breaks down carbohydrates

A

amylase and membrane bound disaccharides

32
Q

where is amalayse produces

A

produces in the pancreas and the saliva

33
Q

stages of carbohydrates digestion

A

is first hydrolysed by amalyse in saliva which hydrolyses the polyscaraide crabohtrdates into the dischaatde maltose then the membranebound maltase hydrolyses the glycosidic bonds to produce glucose

34
Q

what is haemoglobin

A

quaternary structure 4 polypeptide chains each containing a haem group

35
Q

what is myoglobin

A

it can store and hold oxygen at even very low partial pressures of oxygen for example repsiring tissues

36
Q

affinity of heomoglobin with oxygen

A

the ability for heamoglobin to bind to oxygen

37
Q

saturation of haemoglobin with oxygen

A

when haemoglobin can bind to maximum amount of oxygen it can hold on to

38
Q

loading/association with oxygen

A

the binding with oxygen and haemoglobin

39
Q

unloading oxygen

A

when oxygen detaches from haemoglobin

40
Q

explain the oxyhaemoglobin disassociation curve

A

high partial pressure will be completely saturated with oxygen
this gives oxygen a high affinity and will bind to more oxygens
a low partial pressure means that there is 50 percent or less oxygen saturation which means that oxygen will have a low affinity which means that oxygen will readily unload this is pariculary useful in respiring tissues

41
Q

whats cooperative binding

A

oxygen can more easily bind to oxygen after the first oxygen has bound this is because haemoglobin changes shape which means that it is easier to load oxygen

42
Q

what is the bohr effect

A

high carbon dioxide partial pressure means that the oxyhaemoglobin disassociation curve shifts to the left
when carbon dioxide dissolves with water in the blood stream it creates carbonic acid which is acidic, changes the shape of haemoglobin which lowers its affinity with oxygen this is useful in respiring tissues

43
Q

artaries

A

the artier’s have thick walls with elastic tissue this allow the artery to stretch and recoil when the heart beats and to maintain high blood pressure
has a folded epithelium which allows it stretch and maintain high blood pressure

44
Q

arteroils

A

mainly circular and constrict to restrict blood flow and can relax to allow full blood flow. they branch off from arteries

45
Q

veins

A

they carry deoxygenated blood and carry blood under a lower pressure
they have a larger lumen and thinner endothelial walls
they have valves to prevent back flow

46
Q

capillries

A

branch off from arterioles
one cell endothelium and have pores
go through tissue this allows quicker and faster diffsuion

47
Q

capillries

A

branch off from arterioles
one cell endothelium and have pores
go through tissue this allows quicker and faster diffusion

48
Q

what is transpiration

A

transpiration is the evaporation from plants through the stomatal pore

48
Q

what is transpiration

A

transpiration is the evaporation from plants through the stomatal pore

49
Q

factors effecting transpiration

A

light intensity has a positive correlation when you increase light intensity you increase transpiration as the stomatal pore opens up i
more water can escape because of a larger surface area for water to escape
humidity has a negative correlation as the water vapor decreases the concentration gradient between the leaf and outside environment.
and wind increases the concentration gradient because wind blows away the water vapour. it has a positive correlation

49
Q

factors effecting transpiration

A

light intensity has a positive correlation when you increase light intensity you increase transpiration as the stomatal pore opens up i
more water can escape because of a larger surface area for water to escape
humidity has a negative correlation as the water vapor decreases the concentration gradient between the leaf and outside environment.
and wind increases the concentration gradient because wind blows away the water vapour. it has a positive correlation

A level Biology (11 decks)

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