chapter 3 breaking down food

Question 1

what are the types of teeth

Answer 1

incisors
canines
pre - molars
molars

Question 2

what are the structure of the teeth

Answer 2

pulp cavity 
enamel - hard put can dissolve in acid  
dentine 
nerve endings 
gum covers the jaw bone 
blood vessels and nerves
cement

Question 3

what are dentists

Answer 3

dentists are health professionals whi advise on tooth care but also repair the damage caused by poor diet and poor tooth cleaning

Question 4

what is the function of saliva

Answer 4

it helps neutrailse the acids in the mouth as its alkaline
contains amylase which starts the digestion of starch
dissolves soluble foods without it it would be hard to swallow

Question 5

what are the benefits of brushing teeth

Answer 5

removes bacteria, or afterwards to remove food particles

- bacteria digest sugar into the food to produce acid

Question 6

how does tooth decay happen

Answer 6

acidic - dissolves enamel and then the softer sensitive, dentine will be damages and this will expose the pulp and then you would get a tooth ache as the nerve endings are stimulated

Question 7

why is tooth decay not felt in till it reaches the pulp

Answer 7

because the nerve ending are not yet exposed

Question 8

how do you reduce the effects of acid

Answer 8

do not eat or drink too much acidic food or drink acidic drinks
drink water with acidc foods to wash it away
clean teeth

Question 9

how is food moved through the digestive system

Answer 9

the salivary glands, pancreas and gut lining contain specialised cells which produce digestive enzymes
the digestive juices containing these enzymes are passed into the gut where they are mixed with the food
the help the mixing process and push food along the muscular walls of the gut contract and relax this is called peristalsis
the squeezing action of peristalsis brings the enzymes in contact with the food molecules
once mixed the conditions have to be right for the enzymes to work

Question 10

what is the function of teeth

Answer 10

large particles are broken down physically be teeth

Question 11

what is peristalsis

Answer 11

a series of wave like muscle contractions that move food to different areas in the gut

Question 12

process of swallowing

Answer 12

reflex action - this occurs when the tongue pushes the food to the back of your mouth, then the epiglottis covers the opening of the windpipe as you swallow, the slimy mucus in the oesophagus in salvia helps the food slip down

Question 13

how do you break down carbohydrates

Answer 13

into sugars, by carbohydrase enzyme produced in the salivary glands, pancreas and small intestine. Amylase is a carbohydrase which cataylses the digestion of starch into sugars

Question 14

how do you break down proteins

Answer 14

into amino acids by protease in acidic conditions in the stomach, the pancreas and small intestine

Question 15

how do you break down fats

Answer 15

into fatty acids and glycerol by lipase enzymes produced in the pancreas and small intestine

Question 16

what conditions do enzymes in the stomach work best in

Answer 16

acidic

Question 17

where is bile produced, stored and how does it get into the small intestine

Answer 17

liver, gall bladder, bile duct

Question 18

what does bile do

Answer 18

neutralises the stomach acid and emulsifies fat to optimise enzyme activity

Question 19

where are soluble products of digestion absorbed

Answer 19

into the blood stream in the small intestine

Question 20

what do the villi do

Answer 20

they increase the surface area for efficient absorption 
they have cells with microvilli 
rich blood supply
one cell thick wall 
lymph system

Question 21

what are amino acids used for

Answer 21

make proteins

Question 22

what are fatty acids, glycerol and glucose used for

Answer 22

energy release

Question 23

what happens to excess glucose

Answer 23

its converted to glycogen and fat for storage

Question 24

what happens to excess amino acids

Answer 24

they are deaminated by the liver and the ammonia produced is converted to urea for excretion

Question 25

what is water absorbed by

Answer 25

the large intestine

Question 26

what happens to the indigestible food

Answer 26

the indigestible food and the bacteria make up the faeces which are egested

Question 27

why do patients with cystic fibrosis have difficulty digesting and absorbing food

Answer 27

due to thick sticky mucus which blocks the pancreatic duct and absorbing surfaces

Question 28

why do patients with coeliac disease have problems absorbing food

Answer 28

trigged by protein and gluten, this causes the immune system to attack the villi, this reduces the surface area of the villi preventing efficient absorption