B2 - Organisation Flashcards
what does the human digestive system provide the body with
nutrients
what does the respiatory system do
provides the body w oxygen and removes carbon dioxide
what are cells
the basic building blocks of all living organisms
what is a tissue
a group of cells with similar structure and function
what are organs
aggregations of tissues performing specific functions
why do enzymes only catalyse specific reactions
due to the shape of their active site
what is the lock and key theory
that the enzyme has a unique active site that fits onto the substrate involved in a reaction
why might the enzyme not work anymore if the temp increases too much
as it may break some of the bonds holding that enzyme together, changing the shape of the active site so the substrate doesnt fit anymore. this means its denatured
what are 2 things which can make an enzyme denatured
pH
temp
where is amylase made
salivary glands
pancreas
small intestine
where is protease made
stomach
pancreas
small intestine
where is lipase made
pancreas
small intestine
what do digestive enzymes convert food into
small soluble molecules which can be absorbed into the bloodstream
what do carbohydrases
break down carbohydrase into simple sugars
what does amylase do
break down starch
what do proteases do
break down protiens into amino acids
what do lipases do
break down lipids to glycerol and fatty acids
where is bile made
in the liver
where is bile stored
the gall bladder
why is bile alkaline
to neutralise hydrochloric acid from the stomach
what does bile do
neutralises hydrochloric acid from the stomach
emulsifies fat to form small droplets to increase the surface area
how do we make a food sample
1 - use a pestle and mortar to break up food
2 - transfer this to a beaker and add distillied water
3 - stir w glass rod to dissolve some of the food
4 - filter using a funnel and filter paper to get rid of the solid bits of food
what is the benedicts test used for
to test for sugars
what is the iodine test used for
test for starch
what is the biuret test used for
to test for proteins
what is the sudan iii test used for
to test for lipids
how do we carry out the benedicts test
1 - transfer 5cm3 of food sample to a test tube
2 - prepare a water bath at 75 degrees
3 - add 10 drops of benedicts solution using a test tube using a pipette and pipette filler
4 - place the test tube in the water bath using a test tube holder, leaving it for 5 mins
5 - if the colour changes from blue to green, yellow or brick red then sugars are present
how do we carry out the iodine test
1 - transfer 5cm3 of food sample to a test tube
2 - add a few drops of iodine solution
3 - gently shake
4 - if the colour changes from orange to black or blue-black then there is starch
how do we carry out the sudan iii test
1 - transfer 5cm3 of food sample to a test tube
2 - use a pipette to add 3 drops of sudan iii stain solution and gently shake
3 - if lipids present, there will be two layers and the top layer will be bright red
how do we carry out the biruet test
1 - transfer 2cm3 of food sample to a test tube
2 - add 2cm3 of biuret solution to the sample and shake
3 - if there is starch, the solution will change from blue to purple
examples of foods containing sugar
biscuts
bread
cereal
what type of sugars can we test for
only reducing sugars not non reducing sugars
examples of food containing starch
pasta
rice
potaotes
examples of food containing protein
meat
cheese
examples of food containing lipids
olive oil
margarine
milk
where are the lungs in your body
the thorax
what are the lungs surrounded by
plural membranes
what is a double ciruculatory system
blood is pumped to the lungs by the right side of the heart and blood is pumped to the body by the left side of the heart
what is the resting heart rate controlled by
a group of cells located in the right atrium that act as pacemakers
what are artifical pacemakers
electrical devices used to correct irregularities in the heart rate
how is the artery adapted
walls are strong and elastic
smaller lumen
walls contain thick layer of muscle to make them strong and elastic fibers to allow them to stretch and spring back
how are capillaries adapted
very small
permable walls
only one cell thick walls
how are veins adapted
bigger lumen
valves to prevent backflow
what do platelets do
they help blood to clot
what is carried in the plasma
red/white blood cells
glucose and amino acids
carbon dioxide
urea
hormones
proteins
antibodies and antitoxins
how are blood cells adapted
no nucleus
bioconcave shape giving a large surface area
contain haemoglobin which oxygen can bind to to make oxyhaemoglobin
what is coronary heart disease
layers of fatty acid build up inside the coronary arteries making them narrow. this reduces the flow of blood through the arteries and a lack of oxygen in the heart
what do statins do
reduce the cholesterol in the blood, slowing down the rate of fatty deposits forming
what do stents do
they keep arteries open
what are statins
drugs to take to thin blood
what are stents
tubes that are inserted inside the arteries to keep them open so blood can pass to the heart.
advantages of stents
efficient way of lowering the risk of heart attack
effective for a long time
recovery time from surgery is quick
disadvantages of stents
risk of surgery complications
risk of infection
risk of thrombosis
advantages of statins
reduces risk of strokes and heart attacks
increase the amount of good cholestrol
may help prevent other dieases
disadvantages of statins
long term drug so someone can forget to take them
side effects such as headaches, kidney faliure, liver damage, memory loss
takes a long time for the drugs to work
why may someone use an artificial heart
if a donor is not avaliable straight away
to allow the heart to rest as an aid to recovery
what are artifical hearts
mechanical devices which pump blood
advantages of artifical hearts
less likley to be rejected by the body as theyre made from plastics and metals
disadvantages of artificial hearts
surgery risks such as infection
dont work as well as natural ones
patients have to take drugs to thin the blood
how may a valve become damaged
heart attack
infection
old age
what can damage to a valve cause
the valve to stiffen or become leaky
what are mechanical valves
man made replacement valves
what are biological valves
replacement valves taken from other humans or animals
what is health
the state of physical and mental wellbeing
what are causes of ill health
disease
diet
stress
life situations
how may diseases interact
defects in the immune system make it more likely to suffer from an infectious disease
viruses living in cells can trigger cancer
immune reactions caused by a pathogen can trigger allergies such as skin rashes and asthma
severe physical ill health can lead to depression and other mental illness
what can some risk factors be which can increase the rate of a disease
lifestyle
substances in the body or enviroment
what are benign tumors
abnormal growth of cells which are contained in one area and do not invade other parts of the body
what are malignant tumours
tumours which invade other parts of the body via the blood
where does most photosynthesis happen in the leaf
palisade mesophyll tissue
what is spongy mesophyll tissue
it has big airspaces to allow gasses to diffuse in and out
where is meristem tissue found
growing tips of shoots and roots
what do pholem transport
food molecules for immediate use or storage
how are pholem adapted
they are elongated cells and have pores in end walls to allow cell sap to move through
what is translocation
when food molecules move through the pholem tissue
how are xylem adapted
hollow tubes strenghtened by lignin
role of stomata
to control gas exchange and water loss
