T2 organisation Flashcards
define tissue
a group of cells that work for a similar function and have a similar structure
define organ
group of tissues working together for a specific function
define organisms
organs grouped which work together, organ systems
name 3 main nutrients
- carbohydrates
- lipids (fats)
- protein
what happens during digestion to molecules?
big molecules get broken down into smaller molecules so it can be absorbed through the bloodstream
what are the stages to digestion?
1.food is chewed inside the mouth and enzymes in the saliva begin to digest the starch into smaller sugar molecules
2.food then passed down the esophagus into the stomach. Enzymes begin to digest proteins
3.the churning action of the stomach muscles turn into a fluid increasing the surface area for enzymes to digest
4.fluid then passes into the small intestine
5.chemicals are released into the small intestine from the liver and pancreas
6.the pancreas releases enzymes which continues the digestion of lipids
what are enzymes?
large protein molecules which also catalyse chemical reactions
what is protean broken down into?
proteases
what are lipids broken down into?
lipase
what are carbohydrates broken down into?
carboghydrases
where are protease found in?
small intestine
pancreas and stomach
where are amylase found in
salvia and pancreatic fluid
where are lipase found In
small intestine and pancreatic fluid
what happens to enzymes when temperatures increase?
they move faster leading to more successful collisions per second between the active site and substrate
what happens to enzymes are optimum temperature?
there is a maximum frequency of successful collisions between the active site and substrate
what happens to enzymes past the optimum temperature?
the activity of the enzyme rapidly decreases to zero
at high temperatures what do enzymes do / look like
the molecules vibrate and change shape of the active site
what happens if we make the PH more acidic or more alkaline
PH drops to zero
what does amylase break down into?
starch molecules into simple sugars
what is the test for the effect of pH on amylase?
- place one drop of iodine solution into each well spotting tile
- take 3 test tubes
- 1st tube, add 2cm*3 of starch solution
- 2nd tube , add 2cm*3 of amylase solution
- 3rd tube, add 2cm*3 of pH5 buffer solution
- place 3 tubes into a water bath at 30 degrees and leave it for 10 minutes to allow the solution to reach correct temperature
- combine the 3 solutions into one test tube and mix with a stirring rod. return to water bath and start a stopwatch
8.after 30 seconds use a stirring rod to transfer one drop of the solution to one well in the spotting tile which contains iodine - iodine should go black/blue showing starch is present
- take sample every 30 seconds until the iodine turns into an orange colour
- orange tells us starch is no longer present
- repeat experiment using different pH buffers like pH 6 7 8
name 2 problems with the test for the effect of pH on amylase
- only taking the sample every 30 seconds means we only have an approximate time for reaction to complete. take sample every 10 seconds
- looking for the time when iodine doesn’t turn blue-black isn’t always obvious so bring several people to look at the spotting tile.
what is the test for starch?
add iodine solution
turns orange- blue/black
what is the test for reducing sugars?
add benedict’s solution
turns blue - green/yellow/brick-red
what is the test for protein?
add biurets solution
blue- lilac/purple
what is the test for protein?
add biurets solution
blue- lilac/purple
what is the test for lipids?
add ethonal
turns cloudy
how long is the average human small intestine?
5 metres
what does the small intestine have millions of inside?
villi
what does villi have to increase the absorption of molecules?
a large surface area
what is inside of the villi called?
microvilli
what do microvilli also have?
a large surface area
what does the villi have so the bloodstream rapidly removes products of digestion?
a very good blood supply
what does the blood supply in the villa increase?
the concentration gradient
what does the villi have that assures a short diffusion path?
a thin membrane
what happens when diffusion can no longer absorb molecules?
does active transport
what are the stages on the heart?
- vena cava bring in deoxygenated blood from the body
- the blood passes from the heart to the lungs in the pulmonary artery, the lungs collect oxygen.
- oxygenated blood from the lungs goes back into the heart in the pulmonary vein
- the oxygenated blood is pumped from the heart to the aorta
what do the valves in the heart prevent?
backflow when the ventricle contracts
what side of the heart is thicker and why?
the left as it pumps blood to the rest of the body
where does the right side of the heart only pump blood to?
the lungs
why does the coronary arteries branch out of the aorta and spread into the heart muscles?
to provide oxygen to the muscle cells for respiration and contaction
what is the natural resting heart controlled by?
a pacemaker
what do arteries do?
carry very high pressure of blood from the heart or organs in the body
what are 2 characteristics of arteries and why?
- have very thick muscular walls, so they can withstand the high pressure of blood
- contain elastic fibres, these stretch when the surge of the blood passes through and recoils in between surges to keep the blood moving
what do capillaries do?
move substances )like glucose and oxygen) from the blood to the cells
what does carbon dioxide do in the capillaries?
diffuse out of the cell to the blood
why do capillaries have very thin walls?
so diffusion path is short
what are 2 characteristics of veins and why?
- have thin walls, the blood pressure is low so it doesn’t need to be thick
- contain valves, to prevent backflow
valves open to allow blood through and close to stop blood from moving backwards
what 4 things do blood contain?
platelets
white blood cells
red blood cells
plasma
what do plasma transport around the body?
dissolved substances
what are the stages for plasma transportaion?
- transports soluble digestion products like glucose from the small intestine to the lungs
- transports carbon dioxide from the organs to the lungs
- transports urea from the liver to the kidney
what do red blood cells transport?
oxygen from the lungs to the body cells
what are haemoglobin?
oxygen carrying molecules
what is it called when haemoglobin carry oxygen?
oxyhaemoglobin
why do red blood cells not contain a nucleus?
for a greater surface area for more haemoglobin
why do red blood cells have dimples?
for a greater surface area for diffusion of oxygen to work in and out of the cells more rapidly
what are the dimples in haemoglobin called?
biconcave disk
what are white blood cells responsible for?
forms part of the immune system for example antibodies
why do white blood cells contain a nucleus?
to store DNA which encodes the instruction given to do their job
what are platelets?
fragments of cells which help blood to clot
what are 3 advantages for donating blood?
- replaces blood loss
2.given platelets to help with clotting - given proteins that are extracted from blood which are useful for
example antibodies
what are the problems of donating blood?
- risk of infections that lead to diseases and death
- has to be the same blood type or they will die
what is cardiovascular disease?
a problem with the heart and blood vessel
is cardovascular disease communicable or non communicable?
non communicable
what is coronary heart disease?
layers of fatty build up in the coronary arteries which go narrow and reduce blood flow causing lack of oxygen for the heart muscle
what are 2 treatments of coronary heart disease?
- statins, drugs that reduce level of cholesterol in the blood
- stent, metal tube that’s inserted to keep it open and allow blood to flow
what happens when heart valves do not fully open?
causes heart to pump harder which can cause it to enlarge as blood isn’t allowed through and can make a person weak and tired
what are the 2 treatments of heart valves
- mechanical valve
- animal valve
what is a disadvantage of an animals valve?
need replacing
what is a disadvantage of a mechanical valve?
can cause blood clotting and need drugs to be taken regulary
what is a disadvantage of donated hearts?
not enough available
need drugs in case of rejection from immune system
what is a disadvantage of an artificial heart?
increased risk of blood clotting
has a short time period
what does the trachea contain large rings of?
cartilage so it prevents it from collapsing during inhalation
what does the bronchi subdivide into?
bronchioles
what does alveoli do?
make sure gases diffuse in and out of the bloodstream
what are 3 advantages for alveoli?
large surface area
thin walls
very good blood supply
what can lead to uncontrolled growth and mitosis?
changes in genes
what are benign tumours?
growth of abnormal cells in one area
what is an example of an environmental cause linked to cancer?
radon
what is radon?
radioactive gas that has ionising radiation which damages the DNA in cells, this risks to lung cancer
define communicable disease
a disease that is spread person the person by pathogens eg virus and bacteria
define non communicable disease
a disease that cannot spread eg coronary heat disease
what are carcinogens?
cigarette smoke that contains chemicals which damage DNA and increase risk of lung cancer
what are 2 risk factors for cardiovascular disease?
a diet containing high fat and low vegetable intake
a died containing high salt which can increase blood pressure
what do epidermal cells make?
epidermal tissues
what is the upper epidermis transparent?
to allow light to come through to pass to photosynthesise cells
what does the waxy cuticle do?
reduces evaporation of water from the surface of the leaf
what does the stomata do?
allows carbon dioxide in and oxygen to leave the cell
controls the amount of water vapour that can pass out of the leaf
what does palisade mesophyll contain?
chlorophyll used to absorb light energy for photosynthesis
under the palisade mesophyll what does the spongy mesophyll do?
has air spaces for carbon dioxide the diffuse from stomata through spongy mesophyll to palisade cells
what are the factors that effect transpiration?
- greater temperatures, more evaporation
- dryer conditions, works faster
- increase wind conditions
- light intensity
