SB8- Exchange And Transport In Animals Flashcards

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1
Q

Tell me ways to speed up diffusion

A

Surfaces are thin - distance the particles travel is not far

Have large surface area - more room for particles to diffuse

Capillaries are just one cell thick, continual blood flow maintains concentration gradient

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2
Q

Tell me about the surface area to volume ratio

A

The larger a cells surface area - the more of a substance can diffuse in and out at a time - if volume too big, it can’t fill up quickly enough

Surface area divided by volume - bigger the ratio, more diffusion

If ratio too small, cells can’t get materials fast enough so there is a limit to the size of cells

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3
Q

How do the lungs have a large surface area to volume ratio

A

Lungs are packed with alveoli - which increase surface area and increase the amount of gas exchange

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4
Q

How are alveolus adapted

Alveoli (plural)

A

Has a one cell thick wall to decrease diffusion distance, round shape gives larger surface area

Carbon dioxide moves in to alveoli and oxygen out to blood cells

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5
Q

What’s the concentration

A

The amount of a substance in a certain volume

Common unit is g/cm^3 or g cm^-3

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6
Q

What is 1 dm equal to?

A

1 litre

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7
Q

What’s 1 litre equal to

A

1000cm^3

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8
Q

How do you calculate concentration

A

Concentration = mass of solute in g / volume of solution in dm^3

M
cv

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9
Q

Why is a movement in diffusion a “net” movement of solute particles

A

Particles in a solution move randomly in all directions - so the overall movement is a net movement

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10
Q

What happens when there’s no concentration gradient and concentrations are the same

A

Ther is no net movement but individual particles are still moving

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11
Q

What’s a concentration gradient

A

The difference between 2 concentrations form a gradient - bigger difference makes steeper gradient and faster rate of diffusion

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12
Q

What is the relationship between rate of diffusion and difference between 2 concentrations

A

There’s a linear relationship, on a graph the line goes through the origin

It’s a directly proportional relationship ship ship

Rate of diffusion (weird is proportion sign) concentration difference

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13
Q

What maintains a concentration gradient in the lungs

A

A good blood supply moves oxygen quickly out of the lungs

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14
Q

How does surface area increase rate of diffusion

A

When surface area is increased - there’s a bigger space on the membrane for particles to cross through in a certain time so overall rate of diffusion increases

But rate at which particles pass through each unit area of the surface membrane is unchanged

Rate of diffusion is proportional to surface area

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15
Q

How does distance change the rate of diffusion

A

The farther particles have to diffuse. The slower the rate of diffusion- so increasing the thickness of a memebrane decreases the rate of diffusion

This is an inversely proportional relationship- when distance doubles, the other halves

Rate of diffusion is proportional to 1 divided by thickness of membrane

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16
Q

What is Ficks law

A

Shows the relationship between variables that affect diffusion

Rate of diffusion is proportional to= surface area x concentration difference / thickness of membrane

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17
Q

Simplify the circulatory system

A

Blood flows away from the heart into the arteries and divide into narrow capillaries which form networks running through tissues, blood returns to the heart in veins

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18
Q

How and why is a pulse formed

A

With each beat, the heart squirts blood into arteries under high pressure

Artery walls are thick to withstand the sudden increase in pressure - but this makes them stretch, a wave of stretching then passes all by the artery walls which is felt as a pulse

A pulse is not your blood moving

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19
Q

What do elastic fibres in the artery walls cause and why is this useful

A

Muscle and elastic fibres in the artery walls cause the arteries to contract again, the stretching and contracting of arteries makes the blood flow more smoothly

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20
Q

Why do veins have thin walls

A

They carry blood under low pressure

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21
Q

What do valves do in the veins

A

Prevent blood flowing the wrong way

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22
Q

How does blood move along veins

A

As You move, muscles in your skeleton help to push blood along the veins

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23
Q

What does an arteries thick wall consist of

A

Thick layer of elastic and muscle fibres

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24
Q

What does consist of

A

Plasma

White blood cells

Platelets

Erythrocytes (red blood cells)

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25
Q

What does plasma do

A

Carries dissolved substances such as glucose, carbon dioxide and urea

26
Q

Why are red blood cells and packed with haemoglobin

A

This substance binds with oxygen in the lungs and releases it again in tissues

Btw when a lot of oxygen is bound to haemoglobin molecules, cells bright red but dark red when less oxygen attached

27
Q

How are erythrocytes adapted (red blood cells)

A

They have no nucleus so there’s more space for haemoglobin- cells are shaped like discs with a dimple on each side
BICONCAVE shape - large surface area to volume ratio for oxygen to diffuse in and out

28
Q

What are the 2 types of white blood cell

A

Phagocytes and lymphocytes

Both remove foreign cells that get inside you

29
Q

What do lymphocytes do

A

Produce proteins called antibodies that stick to foreign cells and help to destroy them

30
Q

What do phagocytes

A

Surround forieign cells and digest them

31
Q

What do platelets do

A

They are tiny fragments of cells that have no nuclei, they produce substances needed to clot the blood at the site of an injury - eg a cut on the skin

32
Q

When does a heart attack occur

A

When blood stops flowing to muscles in part of the heart - damaging them and stopping the heart pump properly - if it stops completely it can often be started again by using electric shocks in a defibrillator

33
Q

How many chambers does the heat have

A

Four

4

34
Q

Tell me how the heart works

A

Blood from most of the body enters through the right atrium through the vena cava

At the same time blood from the lungs enters through the pulmonary vein into the left atrium , when theses top chambers are full, muscles around them contract to push blood into ventricles - walls in ventricles contract forcing blood out of the heart - as this happens muscles in the atria walls relax and these chambers re fill with blood

35
Q

Tell me about atria

A

In the heart, there are 2 atria which contract and push blood into ventricles

36
Q

What’s the aorta

A

Carries blood to rest of body

37
Q

What’s the superior vena cava

A

BRings blood from the upper body

38
Q

Where does the pulmonary artery go

A

To the lungs

39
Q

Where does the pulmonary vein go

A

From the lungs

40
Q

What’s the inferior vena cava

A

Brings blood from the lower body

41
Q

What are tendons in the heart

A

Stop valves turning inside out

42
Q

What is the septum in the heart

A

Comepeltly separates the two sides of the heart

43
Q

What colour are parts of the heart with deoxygenated blood

A

Dark red

44
Q

What colour are parts of the heart that pump oxygenated blood

A

Bright red

45
Q

What is the contraction and relaxation of muscles during each heart beat caused by

A

They are controlled by impulses from the nervous system

46
Q

What is heart rate

A

The number of times the heart beats in a minute

47
Q

What’s the stroke volume

A

The volume of blood pushed around into the aorta in each beat
Measured in litres

48
Q

What is cardiac output

A

The volume of blood pushed into the aorta each minute calculated using equation=

Cardiac output(litres/min) = stroke volume (litres/beat) x heart rate (beat/min)

49
Q

Why do fitter people often have bigger stroke volumes and hearts can beat more slowly to achieve same cardiac output

A

Regular expertise increases the strength of heart muscle and ventricle size

50
Q

What’s cellular respiration

A

A series of chemical reactions that release energy from glucose - some energy transferred out of cells by heating

51
Q

What type of reaction is respiration

A

Exothermic

52
Q

Where do most of the reactions in aerobic respiration happen

A

It needs oxygen, most processes occur in mitochondria of the cell

53
Q

Tell me the word equation of aerobic respiration

A

Glucose + oxygen —> carbon dioxide + water

54
Q

What does the circulatory system ensure for aerobic respiration

A

Cells have a good supply of oxygen and glucose and waste is carried away from cells

55
Q

Why does rate of Aerobic respiration increase during exercise

A

Muscles neee more energy, cells take more oxygen and glucose from the blood - hear beats faster, breath faster and deeper and increase amount of oxygen diffusing into the blood in your lungs - faster breathing allows your lungs to excrete more carbon dioxide

56
Q

When is anaerobic respiration used

A

During very strenuous exercise, oxygen is used up faster than it’s replaced

57
Q

What happens in anaerobic respiration

A

Occurs in the cytoplasm of cells, it does not require oxygen but produces lactic acid

Glucose —-> lactic acid

58
Q

Which respiration releases more energy from glucose

A

Anaerobic respiration release less energy from glucose, anaerobic causes muscle to tire quickly but can have bursts of energy without needing an increase in oxygen supply

59
Q

When is anaerobic respiration useful

A

When animals need to move fast and suddenly - such as moving away from a predator

60
Q

Why can heart and breathing rates remain high after exercise

A

Because extra oxygen is needed to replace the oxygen lost from blood and muscles

Extra oxygen is also needed to release the extra energy required to get rid of lactic acid