digestive system and enzymes

Question 1

tissue

Answer 1

a group of specialised cells working together

Question 2

organs

Answer 2

collections of tissue often containing several tissues each

all of them have adaptations

Question 3

pancreas

Answer 3

an organ that makes hormones to control blood sugar and some of the enzymes that digest food

Question 4

organ systems

Answer 4

a multicellular organism has multiple working together.

Question 5

the human digestive system

Answer 5

between 6 and 9m long

exchanges substances with the environment

Question 6

insoluble molecules

Answer 6

in the food we take in.

the body cannot absorb these so they need to be broken down / digested to form soluble molecules

Question 7

soluble molecules

Answer 7

can be taken in and used by your cells

they are broken down into your blood in the small intestine

Question 8

enzymes

Answer 8

break down food and speed up reactions
(the substrate fits into the active site and they react rapidly. products are released afterwards)

without them bodily reactions would not be fast enough to keep you alive

Question 9

temperature and enzyme action

Answer 9

temp up = rate up

enzymes usually denature past 40° (shape of the active site changes)

some can survive in higher temperatures such as bacteria in hot springs
deep sea creatures’ enzymes can work at 0° or below

Question 10

a change in pH causes enzymes to stop working because…

Answer 10

they interfere with the forces that hold together the shape of the active site (they hold the amino acid chains together)

Question 11

digestive enzymes work…

Answer 11

while most enzymes work inside bodily cells, digestive enzymes work OUTSIDE.

Question 12

where are digestive enzymes produced?

Answer 12

by specialised cells in glands and in the lining of the digestive system

Question 13

digestive system adaptations

Answer 13

• large surface area for enzymes to work on
• mixes food and digestive juices so the enzymes come into contact with as much food as possible
• has different pH levels

Question 14

carbohydrase

Answer 14

enzymes that break down carbohydrates

Question 15

amylase

Answer 15

starch -> sugars

produced in the
salivary glands and pancreas

starch starts digestion in the mouth

Question 16

protease

Answer 16

proteins -> amino acids (meat, fish, cheese)
produced by
stomach, pancreas and small intestine

Question 17

lipase

Answer 17

lipids -> fatty acids and glycerol
(fats+oils)

made in your pancreas and small intestine

Question 18

stomach acid

Answer 18

stomach acid is quite concentrated and kills most bacreria in your foods

your stomach produces a thick layer of mucus to protect the stomach walls from enzymes and acid

Question 19

bile

Answer 19

the liver makes bile which is squirted onto the food through the bile duct when food passes from the stomach to small intestine

this is because the small intestine works best in alkaline conditions and bile can neutralise it

Question 20

bile (second function)

Answer 20

it emulsifies fats in your foods
(breaks up large drops of fat into smaller droplets)
this provides more surface area for enzymes to work on.