B2a- human digestive system

Question 1

what is the role of the oesophagus

Answer 1

muscular tube that carries food down to the stomach

Question 2

what is the role of the stomach?

Answer 2

contracts to churn up food

Question 3

what is the role of the pancreas?

Answer 3

to make and release enzymes

Question 4

what is the role of the liver?

Answer 4

makes bile

Question 5

what is the role of the small intestine?

Answer 5

breaks down and absorbs small,soluble food molecules

Question 6

what is the role of the large intestine

Answer 6

absorbs water from undigested food

Question 7

What chemical would you use to test for starch?

Answer 7

iodine

brown/orange -> blue/black

Question 8

What chemical would you use to test for carbohydrates?

Answer 8

benedicts

blue -> brick red

Question 9

what chemical would you use to test for protien?

Answer 9

biuret reagant

blue -> purple

Question 10

what chemical would you use to test for lipids?

Answer 10

ethanol and water

clear -> cloudy white

Question 11

enzymes- carbohydrase

Answer 11

breaks down carbohydrates
product- simple sugars
made in- salivary glands, pancreas, small intestine

Question 12

enzyme- amylase

Answer 12

breaks down starch
product- glucose
made in- salivary glands, pancreas and small intestines.

Question 13

enzyme- protease

Answer 13

breaks down protein
product- amino acids
made in the stomach, pancreas and small intestine

Question 14

enzyme-lipase

Answer 14

breaks down lipids
product- glycerol and fatty acids
made in pancreas and small intestine

Question 15

describe two functions of bile

Answer 15

neutralizes stomach acid, providing the alkaline conditions needed in the small intestine
emulsifies fat- turning large droplets of fat into lots of smaller droplets, therefore providing a larger surface area over which the lipase enzymes can work

Question 16

test for starch (3)

Answer 16

place 2cm cubed of food solution into test tube
add iodine solution
if present, solution will turn blue/black

Question 17

test for sugars (5)

Answer 17

place 2cm cubed of food solution into test tube
add 10 drops of benedicts
place test tube into beaker and fill beaker half way with hot water
leave for 5 minutes
if sugar is present, colour will change from blue -> brick red

Question 18

test for protein (3)

Answer 18

add 2cm cubed of food solution into a test tube
add 2cm cubed of biuret solution
if present, will change from blue -> purple

Question 19

test for lipids/fats

Answer 19

transfer to 2cm cubed to food solution to a test tube
add few drops of distilled water and a few drops of ethanol
shake solution
if present, clear->cloudy white