B2 Organisation Flashcards
what is the circulatory system
transports oxygen nutrients and waste products in the blood
nervous system
co-ordinates all of the bodies activities
muscular skeletal system
provides support stability and movement
respiratory system
exchange of gasses
digestive system
to break down food molecules contains the stomach small intestine and the large intestine
nervous system
brain spinal cord and neurons
mouth
chews food in two different ways - chemical and mechanical
salivery glands
produces saliva to aid digestion
what happens in the oesophogus
food travels down into the stomach
small intestine
brakes down food and collects the nutrients
large intestine
unchewed food gets broken down
rectum
where your feces is stored
what happens in the mouth
your teeth chew the food and the salivery glands produce saliva (containing enzymes) to break down the food
what happens in the stomach
hydrochloric acid breaks down food even further. it is churned around by muscles so it becomes a liquid, protease is produced
what happens in the liver
bile is produced which breaks down fats and neutralises acids
what are the adaptations of the small intestine
there is a large surface area because of the villi which are the tiny hair like structures which absorb the nutrients and the enzymes protease and amaylase are produced
what happens in the large intestine
water is absorbed
what happens in the anus
defectation
what are carbohydrates
molecules that are made up of the elements carbon and hydrogen
what are protiens
molecules that are made up of the elements carbon hydrogen oxygen and nitrogen protiens are made up of long chains of amino acids
what are lipids
molecules that are made up of the elements carbon hydrogen and oxygen, lipids can be fats or oils
what is the food test for starch
grind sample
add iodine
positive result = blue/black
negative result = orange/brown
what is the food test for lipids
grind sample
mix with water
filter mixture
add ethanol
positive = cloudy white
negative = clear
what is the food test for sugar
grind sample
mix with water
funnel mixture
add bennedicts solution
positive = red/orange/yellow/green
negative=brown
what is the test for protein
grind sample
mix with water
funnel mixture
add biruet soloution and shake
positive = purple
negative = blue
what is a positive starch test result colour
blue/black
what is a positive fats test result colour
cloudy white
what is the positive result for protein colour
purple
what is the positive result colour sugar
red/orange//green
what is lipase
breaks down fatty acids and glycerol
what is protease
breaks down proteins and amino acids
what is amylase
breaks down starch and glucose
what is carbohydrase
breaks down carbohydrate and simple sugars
how does blood flow around the body
arterys carry blood through the heart to the organs of the body. blood returns to the heart in the veins the twp are linked by a capilary network
what are the different types blood vessels
the main types of blood vessels are arterys veins and capilary networks
why are valves important
the valves prevent backflow ensuring that blood flows in the right direction
why are double ciruclaroy systems important
a double circulatory system is important in warm blooded active animal such as human - makes a circulatory system more efficient
what is an enzyme
an enzyme is a catalist that increases the speed of a reaction without being changed or used up in a reaction. enzymes are all large protiens and all proteins and all proteins are made up of chains of amino acids.
what is the structure of an enzyme
every enzyme has an active site with a unique shape that fits onto the substance involved in a reaction. enzymes usually only place one specific reaction.
why do enzymes only catalyse one specific reaction
because in order for the enzyme to work the substrate has to fit into its active site. if the substrate e doesn’t match the enzymes active site then the reaction won’t be catalysed
how does temperature affect enzymes
at first a higher temperature increases the rate of the reaction
but if it gets too hot some of the bonds holding the enzyme together break. this changes the shape of the enzymes active site,so the substrate won’t fit anymore. the enzyme then becomes denatured
how does pH affect enzymes
if the pH is too high or too low then it interferes with the bonds holding the enzyme together. this changes the shape of the active site and causes the enzyme to denature. all enzymes have an optimum pH they work best at, it is often pH 7 but not always
what is the method for the practical of investigating enzymatic reactions
1) put a drop of iodine into every well of a spotting tile
2) place a Bunsen burner om a heat proof mat and a tripod and gauze over the Bunsen burner. put a beaker of water on top of the tripod and heat the water until 35 degrees. try to keep the temperature of the water constant throughout the experiment
3) use a syringe to add 1 cm3 of amylase solution and add 1 cm3 of a buffer solution with a pH of 5 to a boiling tube. using test tube holders put the tube into the beaker and wait for 5 minutes
4) next use a different syringe to add 5 cm3 of a starch solution to the boiling tube
5) immediately mix the contents of the boiling tube and start a stop clock
6) use continuous sampling to record how long it takes for the amylase to break down all of the starch. to do this use a dropping pipette to take a fresh sample from the boiling tube every 30 seconds and put a drop into a well. when the iodine solution remains and browny -orange starch is no longer present
7) repeat the whole experiment with buffer solutions of different pH values to see how pH affects the time taken for the starch to be broken down
how to calculate the rate of reaction for the practical of investigating enzymatic reactions
rate of reaction = 1000 / time
for example at pH 6 the time taken for amylase to break down all of the starch in a solution was 90 seconds. so the rate of reaction = 1000 / 90 = 11
where are the lungs located
the thorax, they are separated from the lower part of the body by the diaphragm. they are protected by the ribcage and are protected by pleural membranes
where does the air that you breathe in go
through the trachea, this splits into two tubes called the bronchi (each one is a bronchus) one going to each lung. the bronchi split into progressively smaller tubes called the bronchioles. the bronchioles finally end at small bags called alveoli where gas exchange takes place
what is the role of alveoli in the lungs
the alveoli carry out gas exchange in the body. the lungs contain millions of alveoli surrounded by a network of blood capillaries.
how do the alveoli carry out gas exchange in the body
1) the blood passing next to the alveoli has just returned to the lungs from the rest of the body,so it contains lots of carbon dioxide and very little oxygen.
2) oxygen diffuses out of the alveolus (high concentration) into the blood. (low concentration) carbon dioxide diffuses out of the blood (high concentration) into the alveolus (low concentration )to be breathed out
3) when the blood reaches body cells oxygen is released from the red blood cells (where there is a high concentration) and diffuses into the body cells (where concentration is low)
4) at the same time carbon dioxide diffuses out of the body cells into the blood. It is then carried back to the lungs
what type of circulatory system is the heart
a double circulatory system
what is the circulatory system made up of
the heart, blood vessels and blood
what happens in the first circulatory system
the right ventricle pumps deoxygenated blood to the lung to take in oxygen. the blood then returns to the heart
what happens in the second circulatory system
the left ventricle pumps oxygenated blood around all other organs of the body. the blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again
what are the walls of the heart made of
muscle tissue
what is the role of valves in the heart
to make sure that blood flows in the right direction - the prevent it flowing backwards
what are the 4 chambers of the heart
right atrium
right ventricle
left atrium
left ventricle
how to the 4 chambers pump blood around the body
1) blood flows into the two atria from the vena cava and the pulmonary vein
2) the atria contract pushing the blood into the ventricles
3) the ventricles contract forcing the blood into the pulmonary artery and the aorta and out of the heart
4) the blood then flows to the organs through arteries and returns though veins
5) the atria refill and the whole cycle starts again
how does the heart get its own supply of oxygenated blood
arteries called coronary arteries branch off the aorta and surround the heart making sure it gets all the oxygenated blood it needs
what are the 3 different types of blood vessel
arteries
veins
capillaries
what is the role of an artery
to carry blood away from the heart
what is the role of a vein
to carry blood to the heart
what is the role of a capillary
these are involved with the exchange of materials at the tissues
how do arteries carry out their function
the heart pumps the blood out at high pressure so the artery walls are strong and elastic
the walls are thick compared to the size of the hole down the middle (the lumen)
they contain thick layers of muscle to make them strong and elastic fibres to allow them to stretch and spring back
how do capillaries carry out their function
arteries branch into capillaries,they are too small to see. they carry the blood really close to evey cell in the body to exchange substances with them. they have permeable walls so substances can diffuse in and out. they supply food and oxygen and take away waste like carbon dioxide
their walls are only one cell thick,this increases the rate of diffusion by decreasing the distance over which it occurs
how do veins carry out their function
capillaries eventually join up to form veins
the blood is at a lower pressure in the veins so the walls don’t need to be as thick as artery walls
they have a bigger lumen than arteries to help the blood flow despite the lower pressure
they also have valves to help keep the blood flowing in the right direction
what is the function of a red blood cell
to carry oxygen from the lungs to all cells in the body.
what is the shape of a red blood cell
a biconcave disc, giving it a large surface area so they can absorb more oxygen . they also don’t have a nucleus to free up space for more oxygen
what is the role of haemoglobin
it is a red pigment in red blood cells. in the lungs the haemoglobin binds to oxygen to become oxyhaemoglobin. in body tissues the reverse happens. oxyhaemoglobin splits up into haemoglobin and oxygen to release oxygen into the cells
what is the role of white blood cells
to defend against infection
what the the 3 things a white blood cell can do to carry out its function
1) some can change shape to engluf unwelcome microorganisms in a process called phagocytosis
2) some produce antibodies to fight microorganisms
3) some produce antitoxins to neutralise any toxins produced by the microorganisms
what is the role of a platelet
to help blood clot
what are platelets
they are small fragments of cells that have no nucleus. lack of platelets can cause excessive bleeding a bruising
what is plasma
a pale straw coloured liquid that carries everything in blood
what is coronary heart disease
when the coronary arteries that supply blood to the muscle of the heart get blocked by layers of fatty material building up
what is the effect of coronary heart disease
causes the arteries to become narrow, so blood flow is restricted and there’s a lack of oxygen to the heart muscle. - this can lead to a heart attack
what is a stent
stents are tubes that are inserted inside arteries. they keep them open, making sure blood can pass through to the heart muscles. this keeps the person’s heart beating
what is a positive of stents
they are a way of lowering the risk of heart attack in people with coronary heart disease. they are effective for a long time and the recovery from the surgery is relatively quick
what is a negative of stents
there is a risk of complications during the operation,and a risk of infection from surgery. there is also the risk of patients developing a clot near the stent - this is called thrombosis
what is cholesterol
an essential lipid that the body produces and needs to function properly. however too much of a certain type of cholesterol can cause health problems.
what does having too much cholesterol do?
causes fatty deposits to form inside arteries. this can lead to coronary heart disease
what do statins do?
they are drugs that reduce the amount of “bad” cholesterol present in the blood stream. this slows down the rate of fatty deposits.
what are 3 advantages of statins
1) they reduce the risk of a stroke,coronary heart disease and heart attacks
2) can increase the amount of beneficial cholesterol in the blood
3) some studies show that they help prevent other diseases
what are 3 disadvantages of statins
1) long term drug that must be taken regularly,there is a risk that someone could forget
2) negative side effects e.g kidney failure,liver failure and memory loss
the effects are not instant and take time to kick in
what is an artificial heart
a mechanical device that pumps blood for people whose hearts have failed.they are only a temporary fix,to keep a person alive until a donor heart is found
what is an advantage of an artificial heart
the heat is less likely to be rejected by the body’s immune system because they are made from metal or plastic.
what is a disadvantage of an artificial heart
they do not work as well as real hearts,parts can wear out or become damage.the blood doesn’t run through the valves as smoothly leading to blood clots or strokes.
what are the effects of damaged valves
causes the valve tissue to stiffen so it won’t open properly. or a valve could become leaky allowing the blood to flow in both directions rather than just forward. meaning the blood doesn’t circulate as effectively as normal.
how to fix a damaged valve
replacement valves,either from humans or other mammals such as cows or pigs (biological valves) or they can be man made (mechanical valves)
what is artificial blood
a blood substitute e.g a salt solution,which is used to replace the lost volume of blood. this gives the patient enough time to produce new red blood cells
what is a communicable disease
one that can be spread from person to person or between animals and people
what is a non communicable disease
one that cannot spread from person to person
what is cancer caused by
uncontrolled cell growth and division
what is a benign tumour
1) where the tumour glows until there is no more room
2) the tumour then stays in one place rather than invading other tissues in the body
3) these are not normally dangerous and the tumour isn’t cancerous
what is a malignant tumour
1)where the tumour grows and spreads to neighbouring and healthy tissues
2) cells can break off and spread to other parts of the body by travelling in the bloodstream
3) the malignant cells invade healthy tissues elsewhere in the body and form secondary tumours
4) malignant tumours and dangerous and can be fatal - they are cancerous
what are 4 risk factors for cancer associated with lifestyle
1) smoking
2) obesity
3) UV exposure
4) viral infections
what is the epidermal tissue of a leaf
covers the whole plant
what is the palisade mesophyll tissue of a leaf
the part where most photosynthesis happens
what is the spongy mesophyll tissue of a leaf
inside the leaf,contains big air spaces to allow gasses to diffuse in and out of cells
what is the meristem tissue of a leaf
found at the growing tip of shoots and roots and is able to differentiate into lots of different types of plant cell, allowing the plant to grow
what is the function of the epidermal tissue
to help reduce water loss by evaporation
what is the function of the upper epidermis
transparent so the light can pass through it to the palisade layer
what is the function of the palisade mesophyll tissue
lots of chloroplasts so they absorb loads of light
what is the function of the lower epidermis
full of holes called the stomata which let carbon dioxide diffuse directly into the leaf.
what is transpiration
the loss of water from the plant caused by the evaporation and diffusion of water from a plants surface.the evaporation creates a slight shortage of water in the leaf and so more water is drawn up from the rest of the plant though the xylem vessels to replace it.
what 4 things affect the rate of transpiration
light intensity
temperature
air flow
humidity
what is the name of the device that can be used to estimate the rate of transpiration
a potometer
how do guard cells control the opening of the stomata
when the plant has lots of water the guard cells fill with it and become plump and turgid that makes the stomata open go photosynthesis can happen
how do guard cells control the closing of the stomata
when the plant is short of water the guard cells loose water and become flaccid making the stomata close this helps stop too much water vapour escaping
other than the guard cells what other 2 things control the opening and closing of the stomata
there are thin outer walls and thick inner walls which help the opening and closing work
the stomata are sensitive to light and so they closer and night to save water and so they don’t loose out of photosynthesis
Give three symptoms of liver failure
No bile made in the liver so fats or lipids are notified
lactic acid is not broken down so your oxygen debt is higher and you have muscle pain or fatigue proteins or Amino acids will not be broken down
amino acids will not be made into urea or will not form ammonia
