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
