organisation and digestive system

Question 1

what are organelles

Answer 1

things that make up cell eg nucleas

Question 2

whats a tissue

Answer 2

a group of similar cells that work for a function

Question 3

what are organs

Answer 3

collection of dif tissues

Question 4

whats an organ system

Answer 4

group of organs that work together eg the digestive or reproductive system

Question 5

what happens when food is first eaten

Answer 5

its physically broken down by chewing and saliva acts as an enzyme against carbs then it goes down the asophagos into the stomach

Question 6

three main traits of stomach

Answer 6

produces pepsin which breaks down protien
hydrochloric acid kills bacteria
contracts muscular walls

Question 7

what happens in small intestine

Answer 7

digestion takes place and food is absorbed into the blood

Question 8

why is the small intestine adapted

Answer 8

pancreas pushes enzymes in to break them down
liver sends bile to gall bladder to intestine which neutralises acid and breaks down any fats
the villa largely increases the SA and is thin so there isnt much to get through

Question 9

carbs general look

Answer 9

made up of sugars, can be simple or complex- complex can be starch, cellulose etc.
most are turned into glucose for energy

Question 10

lipids general

Answer 10

lipids are fats and oils depending on their melting point. they are made of fatty acids and glycerol

Question 11

protiens general

Answer 11

made up of amino acids they are the building blocks of cells and tissues. they hold speciific 3d shapes which will become denatured if lost

Question 12

functions of protiens

Answer 12

structures of muscles and tendons
hormones
antibodies
enzymes

Question 13

required prac food test starter

Answer 13

take food sample and grind it with some water to form a paste and then put it in water until it dissolves, then funnel out any excess so you have a solution- not with lipids

Question 14

test for starch

Answer 14

add orange iodine and it will go black

Question 15

test for sugars

Answer 15

add ten drops of benedict and put the tube in a half filled hot beaker. sugar will go up the rainbow from blue depending on how sugary. only works for reducing sugars

Question 16

test for protien

Answer 16

add buriet and it will go from blue to lilac

Question 17

test for lipids

Answer 17

no filter because itll stick. add water and ethanol and it will go white

Question 18

what is an enzyme

Answer 18

a catalyst made by living organisms and amino acids

Question 19

what is lock andkey and induced fit

Answer 19

originally it was believed that the active site formed by the amino acids fit perfectly into its subbstrate but now we know it can change

Question 20

what is metabolism

Answer 20

controlled by enzymes its the sum of all the reactions

Question 21

effect of temp on enzymes

Answer 21

if theyre above 40c then they can change the active site and it will become denatured

Question 22

effect of ph on enzymes

Answer 22

a change in ph affects the forces that hold the chain of protien molecule so it will change, often gradually until it becomes fully denatured
enzymes have dif optimal ph

Question 23

what are digestive enzymes

Answer 23

made in glands and in the system and they speed up the breakdown of foods

Question 24

what and where breaks down carbs

Answer 24

amalyse/carbohydrase breaks it down from the pancreas and saliva into simple sugars

Question 25

what and where breaks down protiens

Answer 25

protease are made in the small intestine and the stomach and pancreas and make amino acids

Question 25

what and where breaks down lipids

Answer 25

lipases from pancreas and small intestine make fatty acids and glycerol- absorbed into blood to needed places from the small intestine

Question 26

explain required practical amalayse

Answer 26

so you have like apaint palette and you put adrop of orange iodine in each hole and then you fill up three test tubes with 2cm each of amayse starch and a ph buffer. put them in a warm water bath for 30s to soak and then mix the mixture. start timer, every 30sadd a drop to one of the iodines in the pallette and after time it should stop going black because starch has fully reacted. repeat this with other ph bffers

Question 27

problems with the ph amalayse experiemtn

Answer 27

because its every 30s the time the reaction ended isnt obvious and also its hard to always see when its not blue black so you may need several opinions

Question 28

what is the ph of stomach and why

Answer 28

the protease enzyme pepsin works best at acidic ph so the stomach produces hydrochloric acid to maintain that. the stomach is also coated in mucus so the acid doesnt attack the walls

Question 29

how is the ph changed in the small intestine

Answer 29

when the acidic stuff comes from the stomach bile comes from the gall bladder and neutralises the acid

Question 30

what does bile do for fat

Answer 30

bile physically breaks it up so the SA is larger to break down

Question 31

things enzymes speed up

Answer 31

breaking down of molecules
changing molecules into dif ones
building large molecules from smaller ones- making starch or glyogen from glucose, co2 and water to make glucose etc

Question 32

whats the dif between polymers and monomers in biological molecules

Answer 32

lipids are not made of polymers, they are just fatty acids bonded to a glycerol, whilst protien is made of achain of monomer amino acids and carbohydrate polymers like glycerol come from a chain of simple sugars

Question 33

jobs of dif enzzymes to catalyse

Answer 33

• building large molecules eg starch or glycogen from glucose
• changing molecules into one another
• breaking large molecules into small ones eg amino into urea