digestive system

Question 1

what is ingestion

Answer 1

taking food in through the mouth and swallowing

Question 2

what is digestion

Answer 2

breaking down large insoluble molecules in food into smaller, soluble molecules

Question 3

what is absorption

Answer 3

movement of small soluble molecules out of the gut and into the blood by diffusion and active transport

Question 4

what is egestion

Answer 4

passing out undigested food through the anus

Question 5

what is assimilation

Answer 5

building larger biological molecules from the small soluble molecules, in all calls

Question 6

where does ingestion take place

Answer 6

mouth

Question 7

what types of digestion happen in the mouth

Answer 7

mechanical and chemical

Question 8

what is mechanical digestion

Answer 8

food is broken up into smaller pieces by chewing. this increases the surface area for enzymes

Question 9

what is chemical digestion in the mouth

Answer 9

saliva in mouth releases amylase which breaks down starch into maltose

Question 10

what does amylase do

Answer 10

turn starch into maltose

Question 11

what is the food made into before swallowing

Answer 11

a bolus

Question 12

how is food pushed down the oesophagus

Answer 12

peristalsis

Question 13

what is peristalsis

Answer 13

wave like contractions causing the oesophagus to widen and pushes food down oesophagus

Question 14

where is pepsin released from

Answer 14

gastric glands in stomach

Question 15

what does pepsin do

Answer 15

turns proteins into peptides

Question 16

why does the stomach also release hydrochloric acid

Answer 16

to ensure an acidic pH for pepsin to be at optimum conditions and kill bacteria

Question 17

what happens in the duodenum

Answer 17

final site of chemical digestion of starch, protein and lipids

Question 18

where are trypsin, amylase and lipase released from

Answer 18

pancreas

Question 19

what does trypsin do

Answer 19

turns proteins to peptides

Question 20

what does lipase do

Answer 20

turns lipids into glycerol + 3 fatty acids

Question 21

what does the duodenum wall release

Answer 21

maltase and peptidase

Question 22

what does maltase do

Answer 22

turns maltose into glucose

Question 23

what does peptidase do

Answer 23

turns peptides into amino acids

Question 24

where is bile produced

Answer 24

liver

Question 25

where is bile stored

Answer 25

gall bladder

Question 26

what does bile do

Answer 26

1 - neutralises stomach acid to 7-8 in duodenum
2 - emulsifies lipids - breakdown large droplets into smaller, increasing SA for lipase to digest

Question 27

what happens in the ileum

Answer 27

absorption

Question 28

where are soluble molecules absorbed

Answer 28

villi - through diffusion and active transport

Question 29

how are villi adapted for diffusion

Answer 29

• large SA from folding of microvilli
• short diffusion distance - 1 cell thick wall
• high concentration gradient - lots of capillaries