aminal nutrition

Question 1

balanced diet

Answer 1

a diet that provides all the necessary nutrients in their required amounts

Question 2

carbohydrates

Answer 2

starch: potatoes, cassava, cereal
sugars: fruits, cane, honey
- contain energy which is released in cells as they are broken down in respiration

Question 3

fats

Answer 3

• provide more energy than carbs + stored under skin and around kidneys
• fat meat, dairy foods, nuts

Question 4

proteins

Answer 4

• growth and repair + make up muscle
• meat, egg white, fish

Question 5

vitamin c

Answer 5

• healthy gums + skin repair
• citrus fruits, fresh cabbage

Question 6

vitamin d

Answer 6

• uptake of calcium + bone formation
• sunlight, fish liver

Question 7

calcium

Answer 7

• healthy bones and teeth + muscle action
• milk, flour

Question 8

iron

Answer 8

• for haemoglobin (oxygen carrying pigment in RBC)
• red meat, spinach

Question 9

fibre

Answer 9

• forms bulk in intestines, preventing constipation
• fruit, vegetables

Question 10

water

Answer 10

• medium of all chemical reactions + cools body
• all food, drinks

Question 11

vitamin c deficiency

Answer 11

scurvy: bleeding gums + wounds do not heal properly

Question 12

vitamin d deficiency

Answer 12

rickets: bow legs or knock knees because growing bones become soft + fractures for older people (because no calcium uptake)

Question 13

ingestion

Answer 13

taking in of substances into the body through the mouth

Question 14

digestion

Answer 14

the breakdown of large insoluble food molecules into small soluble molecules using mechanical and chemical process

Question 15

mechanical digestion

Answer 15

chopping and grinding food using teeth and muscular churning of food in the stomach

Question 16

chemical digestion

Answer 16

breakdown of large insoluble molecules into small soluble ones using enzymes

Question 17

absorption

Answer 17

movement of small food molecules and ions into the blood through the walls of the intestines

Question 18

assimilation

Answer 18

movement of digested food molecules into cells where they are used becoming part of the cells

Question 19

egestion

Answer 19

passing out food that has not been digested or absorbed through the anus

Question 20

mouth

Answer 20

• teeth mechanically digest food
• salivary glands release saliva with amylase which digests starch
• tongue rolls the food into a bolus

Question 21

oesophagus

Answer 21

waves of muscular contractions (peristalsis) push bolus to the stomach

Question 22

stomach

Answer 22

churns food + walls release gastric juice containing
- enzyme pepsin (protein to polypeptides)
- hydrochloric acid (optimum pH for pepsin to digest protein + kill pathogens)

Question 23

duodenum

Answer 23

receives bile
pancreatic juice
walls release intestinal juice containing:
- maltase (maltose to glucose)
- protease (polypeptides to amino acids)
- lipase (fat to fatty acid + glycerol)

Question 24

pancreas

Answer 24

pancreatic juice containing:
- amylase (remaining starch to maltose)
- lipase (fat to fatty acid + glycerol)
- trypsin (remaining protein to polypeptides)

Question 25

liver

Answer 25

produces bile which:
- emulsifies fat (increase surface area for enzyme to operate)
- neutralises acidic chyme so enzymes can work

Question 26

ileum

Answer 26

where most of digested food is absorbed + most water too

Question 27

features of ileum

Answer 27

• about 6m long
• folded walls
• walls have microscopic finger-like projections called villi

Question 28

villi adaptations

Answer 28

• very thin walled so
• blood capillaries just beneath walls
• special structures (lacteals) to absorb fatty acids and glycerol
• numerous so large surface area
• can move

Question 29

colon

Answer 29

where water is absorbed

Question 30

rectum

Answer 30

muscular chamber where undigested food is stored before being pushed out of anus

Question 31

anus

Answer 31

closed by a ring of muscle (anal sphincter) which is relaxed during egestion

Question 32

glucose + amino acids after absorption

Answer 32

carried by a blood vessel called the hepatic portal directly to liver for first stage of treatment in body

Question 33

fats after absorption

Answer 33

travel in the lymphatic system, bypassing the liver and enter the circulatory system through a vein at the neck

Question 34

four types of teeth

Answer 34

• incisors
• canines
• pre-molars
• molars

Question 35

incisors function

Answer 35

biting + cutting

Question 36

canine function

Answer 36

biting + cutting/tearing

Question 37

pre-molar function

Answer 37

crushing + grinding

Question 38

molar function

Answer 38

crushing + grinding

Question 39

enamel

Answer 39

hardest substance in human body

Question 40

dentine

Answer 40

living part of the tooth + similar to bone

Question 41

pulp cavity

Answer 41

contains nerves + blood vessels

Question 42

cement

Answer 42

holds tooth in socket + allows little movement, preventing damage when chewing hard substances

Question 43

gums

Answer 43

soft tissue that surrounds + protects jawbone + roots of teeth