Nutrition (humans) Pg17,18

Question 1

What do digestive enzymes do

Answer 1

They break down big insoluble molecules into smaller soluble molecules

Question 2

What does amylase do

Answer 2

breaks down starch into maltose

Question 3

What does maltase do

Answer 3

breaks down maltose into glucose

Question 4

What do proteases do

Answer 4

breaks down proteins into amino acids

Question 5

What do lipases do

Answer 5

breaks down lipids into glycerol and fatty acids

Question 6

What does bile do

Answer 6

neutralises stomach acid and emulsifies fats

Question 7

Where is bile produced and stored and then released

Answer 7

Bile is produced in the liver and stored in the gall bladder before it is released into the small intestine

Question 8

how does bile neutralise stomach acid

Answer 8

It is alkaline so it can neutralise stomach acid and makes it alkaline as enzymes work best in alkaline conditions

Question 9

why does bile emulsifies fat

Answer 9

breaks fat down into tiny droplets so it gives the fat a bigger surface area for the lipase to work on, which makes digestion faster

Question 10

How is food moved along the gut

Answer 10

by peristalsis

Question 11

How does peristalsis work

Answer 11

Muscular tissues contract through the alimentary canal, it squeezes balls of food (boluses) through your gut - otherwise it would get stuck with bits of old food.

Question 12

define peristalsis

Answer 12

The squeezing action, which is caused by waves of circular muscle contractions

Question 13

What is another word for alimentary canal

Answer 13

the gut

Question 14

name the organs used in the alimentary canal

Answer 14

Mouth, oesophagus, stomach, liver, pancreas, gall bladder, small intestine, large intestine and rectum

Question 15

What does the mouth do in the digestive system

Answer 15

• Salivary gland in the mouth produce amylase enzyme in the saliva
• teeth break down food

Question 16

What does the stomach do in the digestive system

Answer 16

• it pummels food with its muscular walls
• produces protease enzyme, pepsin
• produces hydrochloric acid which kills bacteria and gives the optimum pH for the protease enzyme to work

Question 17

What does the oesophagus do in the digestive system

Answer 17

• Muscular tube that connects from the mouth to the stomach so food can pass through

Question 18

What does the pancreas do in the digestive system

Answer 18

Produces protease, amylase and lipase enzymes, then it releases it into the small intestine

Question 19

What does the liver do in the digestive system

Answer 19

Where bile is produced

Question 20

What does the gall bladder do in the digestive system

Answer 20

where bile is stored

Question 21

What does the small intestine do in the digestive system

Answer 21

• Produces protease, amylase and lipase enzymes to complete digestion
• This is also where the nutrients are absorbed out of the alimentary canal into the body

Question 22

What does the large intestine do in the digestive system

Answer 22

Where excess water is absorbed from the food

Question 23

What does the rectum do in the digestive system

Answer 23

• is the last part of the large intestine
• Where the faeces (made up of mainly indigestible food) are stored before they exit your body through the anus

Question 24

What is the first and last part of the small intestine called

Answer 24

The first part is called duodenum and the last part is called ileum

Question 25

What is another word for the large intestine

Answer 25

The colon

Question 26

How is the small intestine adapted for the absorption of food

Answer 26

• It is very long, so there is a lot of time to break down and absorb all the food before it reacted the end
• It has a really big surface area for absorption because the walls of the small intestine are covered with millions of tiny projections called villi
• Each cell on the surface of a villus also has its own microvilli - little projections which further increase the surface area of the small intestine
• villi have 1 cell thick wall
• villi have a very good blood supply to assist quick absorption