Utilisateur
similar cells working together to carry out a particular function. This can include more than one type of cell
a group of different tissues working together to perform a function
a group of organs working together to perform a particular function
they contract to move whatever they are attached to
make and secrete chemicals such as enzymes and hormones
covers parts of the body such as the inside of the gut
break down and absorb food
Glands - pancreas & salivary glands
Stomach
Small intestine
Liver
Large intestine
gullet
gall bladder
rectum
the salivary gland and pancreas produce digestive juices. Ghe salivary gland produces amylaze enzymes in the saliva, the pancreas produces protease, amylase and lipase and releases them into the small intestine
- it pummels the food using its muscular walls
- it produces protease (pepsin)
- it produces hydrochloric acid to kill bacteria and give the right pH for protease to work (pH2- acidic)
producing enzymes to complete digestion and absorbing soluble food molecules into the blood
produce bile
absorb water from undigested food, leaving faeces
enzymes
a substance which increases the speed of a reaction without being changed or used up
the side of the enzyme with a unique shape that can only be fit by the specific substance involved in the specific reaction that enzyme catalyses
substrate
the bonds holding the enzyme together break, changing the shape of the active site, meaning the substrate will no longer fit, therefore the enzyme is denatured
temperature and pH
this interferes with the bonds holding the enzyme together, this changes the shape of the active site and denatures the enzyme
rate = 1000 divided by time in seconds
OR
rate = change (eg. amount of product formed) divided by time
break down big molecules into smaller ones so they can pass more easily through the walks of the digestive system, allowing them to be absorbed into the bloodstream
convert proteins into amino acids
stomach
pancreas
small intestine
covert lipids into glycerol and fatty acids
fars and oils
pancreas
small intestine
convert carbohydrates into simple sugars
amylase
starch into sugars such as maltose and dextrins
salivary glands
pancreas
small intestine
neutralise stomach acids and emulsifies fats
where the faeces (indigestible food) is stored before being pood out
where bile is stored before being released into the small intestine
-break it up using pestle and mortar
- transfer to beaker and add distilled water
- stir mixture to dissolve food
- filter the solution using a funnel lined with filter paper
- prepare food sample and transfer 5cm3 to a test tube
- prepare a water bath to 75°C
- add 10 drops of benedicts solution using a pipette
- place test tube in water bath and leave it fir 5 min. ensure test tube is pointing away from you
- if food sample contains reducing sugar, the solution will turn from blue to green yellow or brick red depending how much sugar is in the food
- transfer 5cm3 of your food sample to a test tube
- add a few drops of iodine solution and gently shake tube to mix contents
- if the sample contains starch the colour of the solution will change from browny orange to black or blue black
- prepare a food sample and transfer 2cm3 of sample to test tube
- add 2cm3 of biuret solution to sample and mix cintents by gently shaking
- if the food samole contains protein the solution will change from blue to purple
- prepare a food sample without filtering
- transfer 5cm3 to test tube
- use a pipette to add 3 drops of sudan III stain solution to the test tube and gently shake the tube
- the sudan solution stains lipids.
- if any are present, the solution will separate out into 2 layers and the top layer (lipids) will turn bright red.