topic 2 - organisation Flashcards
principles of organisation order them from smallest to largest
cell tissue organs organ system organism
cell
is the smallest structural and functional unit of an organism
tissue
a group of similar cells with similar structure and function
organ
a group of tissues working together to perform a specific function
organ system
a group of organs working together to perform a specific function
organism
a group of organ systems working together
define digestion
digestion is where large insoluble molecules are broken down into smaller soluble ones that can be absorbed into the bloodstream.
explain the digestion system
first food is chewed up in the mouth. enzymes in the saliva begin to digest the starch into smaller sugar molecules
the food then passes down the oesophagus and into the stomach. in the stomach, enzymes begin the digestion of proteins
the stomach produces hydrochloric acid which helps the enzymes digest proteins
stomach
produces hydrochloric acid
produces hydrochloric acid to kill bacteria
provide optimum ph for the enzymes to digest proteins
liver produces
bile which is stored in the gall bladder which helps with digestion of lipids
the large intestine
absorbs water from undigested food to produce faeces
small intestine
is where soluble molecules are absorbed into the bloodstream
glads - pancreas and salivary glands
produces digestive juice containing enzymes to break down the food
enzymes
are biological catalyst that speed the chemical reaction without being used up
define protein
are long chains of amino acids
what are enzymes made up of
enzymes are large proteins molecules
what are the lock and key? hypothesis
where the substrate has to have a complementary shape to fit the active site
all the key points of enzymes
enzymes are made of proteins and are biological catalyst that speed up the chemical reaction without being used up. the shape of the active site of enzymes is specific for each substrate.
what breaks down proteins
protease
what do protease convert proteins into
amino acid which is absorbed into the bloodstream
the stages of protease
proteins are broken down by enzymes called protease. when we digest proteins the protease enzymes convert into individual amino acid which is absorbed into the bloodstream. protease is made in the stomach, small intestine and pancreas
where are protease broken down into
stomach
small intestine
pancreas
what do carbohydrates break down into
carbohydrates
stages of carbohydrase
carbohydrates are broken down by enzymes called carbohydrase
carbohydrase convert carbohydrates into simple sugar
amylase is an example of carbohydrates it breaks down starch
amylase is made in 3 places - pancreas , salivary glands and the small intestine
carbohydrase convert carbohydrates into
into simple sugar
an example of carbohydrates
amylase
amylase breaks down into
starch
amylase is made in …
small intestine
salivary gland
pancreas
lipase convert lipids into
fatty acids and glycerol
lipase are made in
pancreas and small intestine
Soluble glucose, amino acids, fatty acids and glycerol pass into
into the bloodstream to be carried to all
the cells around the body.
They are used to build new carbohydrates, lipids and proteins, with
some glucose being
used in respiration.
where is the bile made and stored and released
bile made in the liver stored in the gall bladder
released in the small intestine
bile has 2 roles ;
-It is alkaline to neutralise the hydrochloric acid which comes from the stomach
emulsifies fats so breaks down large drops of fat into smaller ones
an example where bile emulsifies fats
bile converts large lipids droplets into smaller droplets
bile emulsifies the lipid what does this do to the surface area
increases the surface area so increase the rate of fat breakdown by lipase
bile is also an alkaline what does this do
neutralises stomach acid, creating an alkaline condition in the small intestine
enzymes require optimum
PH and temperature
the optimum temperature
the optimum temperature is around 37 degree
as the temperature increases the rate of reaction also increases this is because there is an increase collision between the substrate and enzymes
but if the temperature is too high
the enzymes will denature this is because at high temperature the enzymes vibrate and the shape of the active site changes
the optimum PH
The optimum pH for most enzymes is 7 and some produced in acidic conditions eg stomach
if the PH is too high or too low the active site denatures This will change the shape of the active site, so the substrate can no longer fit in
the forces that hold the amino acid chains that
make up the protein will be affected
Required Practical 5: Effect of pH on Amylase - method
- take 3 test tube and add starch solution, analyse solution and a buffer solution to each test tube
- place them in a water bath at 25c for a few minutes
- put a drop of iodine solution in each well of a spotting tile
- now combine the 3 solutions into one test tube and mix with a stirring rod
- after a 30-second transfer one drop of the combined solution to a well in the spotting tile that contains iodine
- the iodine should be blue-black meaning that starch is present
- repeat this process at fixed 30s interval until the iodine solution remains orange-brown
- when the iodine remains orange this tell us that starch is no longer present
- Calculate the rate of reaction using 1 / time taken for solution to remain brown
- Repeat at different pH values using different buffer solutions
Which enzyme catalyses the breakdown of starch in
the human digestive system?
Amylase - catalyses the breakdown of starch to
maltose
Why must samples be left in the water
bath before solutions are mixed?
To allow the temperature to equilibrate
What is a buffer solution?
A solution which can resist changes in pH
In experiments where you are measuring how much of a product forms over time or how much of a
a reactant is used up, you should calculate the rate using the equation:
rate = change/time
problems with this experiment
we are only taking samples every 30s so we only have an approximate time for reaction to complete
solution - shorten the time interval eg 10s
iodine takes time to turn blue/black - the colour change trends to be gradual
solution - several people to look at the spotting tile
Required Practical 4: Food Tests - Describe how you would prepare a sample of
food to be tested
first, prepare the food sample
grind up the food sample using a pestle and mortar
transfer the ground up food to a beaker and add some distilled water and stir it with a glass rod
filter the solution using a funnel lined with filter paper to get rid of the solid bits of food
Describe how you would test for the presence
of starch in a sample
use iodine solution to test for starch. make the food sample and transfer 5cm of your sample into a test tube add few droplets of iodine solution and if starch is present the iodine solution will turn from browny-orange to black-blue
Iodine test for
starch
what colour does iodine solution change into
orange to blue/black
Describe how you would test for the presence of
reducing sugar in a sample
place 2cm^3 of food solution into a test tube
add few drops of benedicts solution into the test tube
place the test tube into a water bath filled in hot water and leave this for 5 minutes
If reducing sugar is present, a brick red
precipitate forms. If not, the solution remains blue
the benedicts solution only works for certain sugars
reducing sugars eg glucose
Benedict’s test for
reducing sugar
Benedict’s test changes to
blue to brick red
but depending how much sugar there is in the food it can turn
green-small amount of sugar
yellow-more sugar present
Describe how you would test for the
presence of protein in a sample
to do this test we take 2cm^3 of the food solution and add 2cm^3 of biuret solution
If protein is present, solution turns from blue to
purple
Biuret test
for protein
if protein is present what colour does it change?
the solution turns from blue to
purple
Describe how you would test for the
presence of lipids in a sample
just like the other test we grind the food using a pestle and mortar and mix it with water but we do not filter the solution because the lipids molecules will stick onto the filter paper
add a few drops of ethanal and few drops of water and gently shake the solution
if lipids are present then a white cloudy emulsion forms
Emulsion test for
for lipids
when testing for lipids what don’t you do
you don’t filter the solution because the lipid molecules will stick onto it
if lipid is present what happens and how
add ethanol which results in a cloudy emulsion if a lipid is present
how else can you test for lipids?
Sudan III test for lipids
Sudan test
red layer forms on top and bottom layer white emulsions forms
adaptation of the small intestine
- long length this provides a large surface area
- covered in millions of villi increases the surface area for the absorption of molecules
- very good blood supply this rapidly removes the product of digestion this increases the concentration gradient
- thin membrane - ensures a short diffusion path
heart
the heart is an organ that pumps blood around the body in a double circulatory system
the double circulatory system is made up of
heart
blood vessels
blood
where does the deoxygenated blood flow into
Deoxygenated blood flows into the right atrium and then into the right ventricle which pumps it to the lungs to undergo gaseous exchange
where does the oxygenated blood flow into
Oxygenated blood flows into the left atrium and then into the left ventricle which pumps
oxygenated blood around the body
the heart process
blood flows into the 2 atria - deoxygenated blood flows into the right atria and through the vena cava and oxygenated blood flows through the left atria though the pulmonary vein
the atria contacts forcing the blood into the ventricles , the ventricles then contract pushing the blood in the right ventricle in the pulmonary artery to be taken in to the lungs. in the lungs the blood collects oxygen. the oxygenated blood is pumped from the heart to the body in the aorta
As this happens, valves close to make sure the blood does not flow backwards.
what side is thicker and why
the left ventricle is thicker because blood needs to be pumped all
around the body rather than just to the lung like the right ventricle.
what is the purpose of the coronary arteries
is to provide oxygen to the muscle cells of the heart
structures of the heart
● the left ventricle is thicker because blood needs to be pumped all
around the body rather than just to the lung like the right ventricle.
● 4 chambers that separate the oxygenated blood from the deoxygenated blood
● Valves to make sure blood does not flow backwards
● Coronary arteries cover the heart to provide its own oxygenated blood supply
the natural, resting heart rate is controlled by
pacemakers
artificial pacemakers
An artificial pacemaker can be used if the individual has an irregular heartbeat. It is an electrical
device that produces a signal causing the heart to beat at a normal speed.
how does an artificial pacemaker work
provide stimulation through small electrical
impulses which pass as a wave across the heart muscle, causing it to contract.
The body contains three different types of blood vessel:
arteries
veins
capillaries
arteries
carry blood away from the heart to the organs in the body
features of arteries
- elastic fibres allows them to stretch this helps the vessels carry blood under high pressure
- thick muscular walls to make them strong
- small lumen
capillaries
involved in exchange of material.
allow the blood to flow very close to cells to enable substances to move
between them
features of capillaries
- very thin walls which creates a short diffusion pathway.
- Permeable walls so substances can move across them
veins
Veins carry blood TOWARDS the heart
features of a vein
- contain valves to stop the blood flowing backwards
- a wide lumen to allow the low pressure blood to flow through
The rate of blood flow is calculated from
the volume of blood/number of minutes.
the blood is made up of
plasma
red blood cells
white blood cells
platelets
function of plasma
this is a liquid and it transport dissolved substances around the body
for example digestion products such as glucose from the small intestine to other organs
the function of red blood cells
red blood cells transport oxygen from the lungs to the body cells
what are the 3 adaptations of red blood cell
- They contain haemoglobin, which binds to oxygen and forms oxyhaemoglobin
- They have no nucleus allowing more room to carry oxygen
- Their biconcave disc shape provides a large surface area
white blood cells
-they are part of the immune system
adaptation of white blood cell
they contain a nucleus this contains DNA which encodes instructions
platelets
They help the blood clot form at the site of a wound
The clot dries and hardens to form a scab, which allows new skin to grow
underneath while preventing microorganisms from entering
Small fragments of cells
no nucleus
what happens in coronary heart disease
layers of fatty material build up inside the coronary arteries as a result of less blood flow to the heart, reducing its oxygen supply. this may lead to a heart attack
statins
drugs that decrease the levels of cholesterol levels (bad cholesterol)
advantages of satins
They reduce the risk of strokes, coronary heart disease and heart attacks
They increase the levels of HDL (good) cholesterol
disadvantage
needs to be taken continuously which may be inconvenience
produce side effects
Stents
Stents (metal mesh tubes inserted in arteries) - keeps the arteries open to allow blood to
flow through.
Heart failure can be solved with
heart transplant
advantages of heart transplant
Less likely to be rejected by the immune system- metal and plastic are not
recognised as foreign
disadvantages of heart transplant
Surgery temporarily leaves the body exposed to infection
As it is mechanical parts of it could wear out and the motor could fail
Blood clots could form, leading to strokes
communicable disease
infectious disease caused by pathogens and can be passed from one person to another
non-communicable disease
diseases that cannot be transmitted from one person to another
Gas Exchange in the Lungs
air enters through the nose or mouth and travels down the trachea
the trachea splits into 2 smaller tubes called bronchi
the the bronchi splits into smaller and even smaller tubes called bronchioles
the bronchioles end in a tiny air sacs called alveoli
alveoli carried million of little air sacs
alveoli is where gases diffuse in/out of the blood stream
alveoli are adapted for gas exchange
the walls of the alveoli are very thin leading to a short diffusion pathway
alveoli have a huge surface area
have a good blood supply
The capillaries provide a large blood supply, maintaining the concentration gradient
a key feature of the trachea
contains rings of cartilage which prevent the trachea from collapsing
factors that may affect health
diet
stress
life situations
Cardiovascular disease
Diet containing lots of LDL (bad) cholesterol results in arteries becoming blocked,
increasing blood pressure
Smoking damages the walls of arteries
Exercise lowers blood pressure, reducing strain on the heart
Type 2 diabetes
Obesity affects the body’s metabolism- fat molecules are released into the blood
which can affect the cells uptake of sugar
Liver and brain function
Alcohol causes fatty liver, which can lead to liver failure
Alcohol can damage nerve cells in the brain
Lung disease and lung cancer
Smoking damages the cells in the lining of the lungs
Pregnancy
Smoking and alcohol can cause many damaging effects on the unborn child
Cancer
Carcinogens such as ionising radiation can lead to cancers
define cancer
cancer is caused by a mutation in the DNA found in cells that leads to uncontrollable cell growth and cell division which results in a tumour
benign
formed in one place will it will grown until there is no more space left
this can put pressure or damage an organ
benign does not spread
has an abnormal growth
malignant
tumour grows and spread around the body
invade neighbouring tissues by traveling in the bloodstream
cancerous
also forms secondary tumour
which cancer travels in the bloodstream
malignant
which cancer is cancerous
malignant
which cancer grows in one place and puts pressure on other organs
benign
Lifestyle risk factors for cancer:
smoking
obesity
UV light skin
Genetic risk factors for cancer -
You can inherit certain genes which increase the likelihood of getting cancer
plant tissues - epidermal tissues
tissue located - covers the whole plant
features - covered in a waxy cuticle
function - reduced water loss by evaporation
stomata
allow carbon dioxide to enter the leaf and oxygen to leave
Palisade mesophyll tissue
found underneath the
epidermal tissue.
features - Has lots of chloroplasts.
function - packed with chloroplast which absorbs the light energy needed for photosynthesis
Spongy mesophyll tissue
found underneath the
palisade mesophyll.
feature -Has lots of air spaces.
function This allows gases to diffuse in and out of cells.
Xylem is found in the roots,
stems and leaves.
features - Lignin makes it strong and waterproof
function - Allows the movement of water
and mineral ions from the
roots to the stem and leaves,
hallow tube
Phloem is found in the
roots stems and leaves.
function - transports dissolved sugar produced by photosynthesis from the leaves to the rest of the pant
Meristematic tissue is found
at the tips of shoots and
roots.
contains stem cells It is able to differentiate into
different types of plant cell.
define translocation
is the movement of dissolved sugar (glucose) rom the leaves to the rest of the plant
transpiration -
Transpiration is the loss of water of water vapour from the leaves and stems of the plant.
The rate of transpiration is affected by the same factors that affect the rate of evaporation.
temperature
humidity
light intensity
air movement
increases temperature
increase in temperature evaporation is faster when temperature is high therefore the rate of transpiration increases. The rate of photosynthesis increases, meaning more stomata are open for gaseous exchange, so more water evaporates and the rate of transpiration increases.
increase humidity
increase in humidity
reduced concentration gradient gradient between the concentrations of water vapour inside and outside the leaf,
resulting in a slower rate of diffusion.
This will decrease the rate of transpiration.
Increase in light intensity
This leads to an increased rate of photosynthesis,
so more stomata
open to allow the gaseous exchange to occur.
This means more water
can evaporate, leading to an increased rate of transpiration.
Guard cells
close and open stomata.
Explain how CHD can cause a heart attack.
reduced blood flow
so less oxygen reaches the heart
so the heart muscle cannot respire
as a result, less energy released
lifestyle - smoking
high bp / cholesterol / fatty deposition
lifestyle -obesity
lack of exercise / high bp / cholesterol / fatty
deposition / diabetes
lifestyle-exercise
reduce obesity / bp /diabetes
lifestyle -diet
obesity / cholesterol / diabetes
lifestyle-high salt intake
high blood pressure
