nutrients and energy

Question 1

what is a balanced diet

Answer 1

a diet that includes all 7 types of nutrients in the right amounts

Question 2

what are the 7 types of nutrients

Answer 2

1.carbohydrates
2.proteins
3.fats
4.minerals
5.vitamins
6.water
7.dietary fibre

Question 3

role of carbohydrates

Answer 3

1.source of energy

Question 4

role of proteins

Answer 4

growth, repair, antibodies, haemoglobin

Question 5

role of fats

Answer 5

source and store of energy, insulation

Question 6

types of minerals

Answer 6

1.calcium:bones and teeth
2.iron:making haemoglobin

Question 7

role of vitamins

Answer 7

vitamin A: night vision
vitamin D: absorption of calcium into bones
vitamin C: protect against scurvy

Question 8

role of water

Answer 8

solvent for metabolic reactions, transport, and cooling of body

Question 9

role of dietary fibre

Answer 9

1.stimulates peristalsis
2.prevents constipation
3.protects against colon cancer

Question 10

examples of malnutrition

Answer 10

1.constipation
2.coronary heart disease
3.obesity

Question 11

cause of constipation

Answer 11

insufficient fibre in the diet, diet lacking in fibre may lead to bowel cancer

Question 12

cause of coronary heart disease

Answer 12

when animal fats and cholesterol form atheroma on the walls of the coronary artery

Question 13

what is associated with obesity

Answer 13

high blood pressure
heart disease

Question 14

what is scurvy disease

Answer 14

1.caused by lack of vitamin c
2.bleeding gums, wounds don’t heal properly

Question 15

what is rickets disease

Answer 15

1.caused by lack of vitamin d
2.growing bones become soft, causing bow legs or knock knees

Question 16

effect of diet lacking in calcium

Answer 16

1.bones of skeleton do not form properly
2.growth is stunted
3.bones become brittle

Question 17

effect of diet lacking in iron

Answer 17

anemia

Question 18

what is kwashiorkor disease

Answer 18

characterized by a swollen abdomen, caused by protein deficiency
immune system is affected as there is difficulty producing antibodies

Question 19

stages of human nutrition

Answer 19

1.ingestion
2.digestion(mechanical and chemical)
3.absorption
4.assimilation
5.egestion

Question 20

what is ingestion

Answer 20

the taking in of substances into the body through the mouth

Question 21

what is digestion

Answer 21

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

Question 22

what is mechanical digestion

Answer 22

breaking down food into smaller pieces to increase surface area for faster action of enzymes

Question 23

what is chemical digestion

Answer 23

breakdown of large insoluble molecules into small soluble ones

Question 24

what is absorption

Answer 24

movement of small food molecules and ions through the wall of the intestine into the blood

Question 25

what is assimilation

Answer 25

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

Question 26

what is egestion

Answer 26

passing out of undigested and unabsorbed food, as faeces through the anus

Question 27

equation of BMI

Answer 27

mass in kg/(height in meters)^2

Question 28

tooth structure

Answer 28

1.the part of the tooth which is embedded in the gum is called the root 2.the crown is covered with enamel 3.under the enamel is a layer of dentine 4.in the middle of the tooth is the pulp cavity which contains nerves and blood vessels

Question 29

what are the four types of teeth

Answer 29

1.incisors 2.canines 3.premolars and molars

Question 30

what are incisors

Answer 30

sharp edges, chisel shaped teeth at the front of the mouth, they are used for biting off pieces of food

Question 31

what are canines

Answer 31

more pointed teeth at either side of the incisors, used to tear meat

Question 32

what are premolars and molars

Answer 32

large teeth towards the back of the mouth, they are cusped and used to crush and grind food

Question 33

tooth decay

Answer 33

1.bacteria forms a layer on teeth called dental plaque 2.if sugar is left on the teeth bacteria in the plaque will feed on it 3.they use it in respiration changing it into acid 3.the acid gradually dissolves the enamel covering the tooth, and works it's way into the dentine

Question 34

what happens in the mouth

Answer 34

1.the teeth grind the food into smaller pieces, increasing it's surface area 2.amylase begins to digest starch in the food to maltose

Question 35

what is the oesophagus

Answer 35

muscular tube that transports food from the mouth to the stomach

Question 36

what happens in the oesophagus

Answer 36

food moves down the oesophagus by peristalsis which is alternative contraction and relaxation of longitudinal and circular muscles in the walls of the alimentary canal

Question 37

what happens in the stomach

Answer 37

1.contains other cells which produce protease enzymes and others which make hydrochloric acid 2.the main protease enzyme in the stomach is pepsin, it begins to digest proteins by breaking them down into polypeptides. pepsin works best in acidic condition 3.acid helps to kill any bacteria in the food and provides the acidic conditions for the activity of the pepsin

Question 38

parts of small intestine

Answer 38

first part nearest to the stomach is called duodenum the last part nearest to the colon is the ileum

Question 39

duodenum

Answer 39

both pancreatic and bile juice are secreted from the pancreas and the liver to the duodenum

Question 40

what does pancreatic juice contain

Answer 40

1.amylase 2. trypsin 3.lipase

Question 41

what does amylase do

Answer 41

break down starch to maltose

Question 42

what does trypsin do

Answer 42

a protease, which breaks down proteins to polypeptides

Question 43

what does lipase do

Answer 43

breaks down fats to fatty acids and glycerol

Question 44

bile juice

Answer 44

bile helps digest fat, by emulsifying large drops of fat into very small ones increasing their surface area to make it easier for lipase in the pancreatic juice to digest them into fatty acids and glycerol.

Question 45

what are the enzymes that iluem produce

Answer 45

1.maltase 2.peptidase 3.lipase

Question 46

what does maltase do

Answer 46

1.breaks down maltose to glucose.

Question 47

what does peptidase do

Answer 47

breaks down any polypeptides into amino acids.

Question 48

what does lipase do

Answer 48

completes the breakdown of fats to fatty acids and glycerol

Question 49

adaption of villi for absorption

Answer 49

1.They are extremely numerous increasing the surface area for faster absorption 2.Their walls are very thin (single layer of cells) for faster absorption. 3.The epithelial cells of the villi have microvilli for further increase in surface area for faster absorption. 4.They have large network of blood capillaries. 5. They have lacteal vessels for absorption of fatty acids and glycerol. 6.Their cells have large number of mitochondria to release energy for active transport.

Question 50

what happens in the large intestine

Answer 50

In the colon, more water and salt are absorbed. However, the colon absorbs much less water than the small intestine.