Human nutrition

Question 1

what is a diet?

Answer 1

the food an animal eats in one day

Question 2

what are the 6 types of nutrients a human needs

Answer 2

carbohydrates, proteins, fats, vitamins, minerals, water, fibre

Question 3

what happens if you don’t have a balanced diet?

Answer 3

if your diet does not contain all of these and in right amounts, your body may not function properly

Question 4

carbohydrates

Answer 4

needed for energy, includes starch and sugar
in most countries there are staple foods that supply most of the carbs
sweet food have carbs

Question 5

fats and oils

Answer 5

needed for energy
to make cell membranes
store extra fats and oils under skin: adibose tissues acts as an insulator
can form around organs, physically protecting them

Question 6

proteins

Answer 6

build cells, for growth
make other proteins: haemoglobin,insulin, antibodies

Question 7

vitamins

Answer 7

organic substances which are only needed in tiny amounts
if you dont have enough you may have a defficiency dissease.
C- keeps tissues in good repair, protein collagen
D- helps Ca absorbs, makes bones and teeth

Question 8

where can u find vitamin c

Answer 8

citrus and raw veggies

Question 9

where can you find vitamin d

Answer 9

butter and egg yolk, sunlight

Question 10

Minerals

Answer 10

inorganic substances
only needed in small amount in our diet
Ca- for bones and teeth, blood clotting
Fe- haemoglobin

Question 11

where can u find Ca

Answer 11

milk, dairy products, bread

Question 12

where can u find Fe

Answer 12

liver, red meat, egg yolk, dark green veggies

Question 13

Fibre

Answer 13

all foods contain fibre, bc of cellulose walls in a plant cell
hard foods- muscles contract stronger
humans cant digest cellulose
helps keep digestive system working properly between mouth and anus
fibrous foods keep the digestive system working

Question 14

peristalsis

Answer 14

rhythmic muscular contractions that move through the digestive system

Question 15

water

Answer 15

important solvent in cytoplasm, if cell is dehydrated the metabolic reactions can’t take place
spaces between our cells are watery liquid
plasma is mostly made of water
a solvent for enzymes and nutrients in the digestive system
needed to get rid of waste products

Question 16

what does the digestive consist of

Answer 16

alimentary canal, liver and pancreas

Question 17

processes of Digestion in order

Answer 17

ingestion- taking food and drink into the mouth using lips, teeth and mouth
Physical digestion- large peices of food broken down into smaller pieces mechanically
chemical digestion- large molecules broken down into smaller molecules by enzymes. molecules must be small enough to pass into the blood.
absorbtion- movement of small molecules and mineral ions through the walls of the intestine and into the blood
assimilation- the nutrients are absorbed by individual cells and used for energy to make new substances
egestion- the material that we can’t digest remains in our intestine and eventually is passed out as faeces.

Question 18

Alimentary canal

Answer 18

tube that runs from mouth to anus
wall contains muscles which contract and relaxes to move food along called peristalsis
canal is lubricated w/ mucus so food can slide easily

Question 19

what is mucus made of

Answer 19

goblet cells which are in the lining of the whole canal

Question 20

sphincter muscles

Answer 20

can close the tube completely in certain places

Question 21

the mouth

Answer 21

teeth bite and grind food to increase surface area
the tongue mixes the food with saliva into a ball, bolus, that can be swallowed
salivary glands makes saliva
amylase begins to digest starch

Question 22

oesophagus

Answer 22

take down food to the stomach
the holed down the middle is called the lumen
the entrance to the stomach is controlled by a spincter muscle. it ope s to let food in then closes

Question 23

the stomach

Answer 23

strong muscular walls which contract to mix the food with mucus and enzymes
cells produce enzyems that break down proteins
cells produce HCL (low ph, kill harmful organisms)
can store food for 1-2 hours

Question 24

small intestine

Answer 24

abt 5meters long
called small because its narrow
duodenum first part nearest to the stomach
ileum last part nearest to the stomach

Question 25

duodenum

Answer 25

pancreatic juice from the pancreas is flows through the pancreatic duct into the duodenum. it is filled with many enzymes o help with chemical digestion in this part of the alimentary canal

Question 26

ileum

Answer 26

is where all digested nutrients are absorbed into the blood

Question 27

large intestine

Answer 27

1.5m long
final part of the alimentary canal
wide
made of colon and rectum

Question 28

colon

Answer 28

absorbs water still left in the food

Question 29

rectum

Answer 29

stores undigested food as faeces. these are then egested through the anus

Question 30

pancreas and the liver

Answer 30

not paert of the alimentary canal but part of the digestive system
pancreas secretes pancreatic juice into the intestine
live creates bile- a yellow/green alkaline watery liquid which helps nutrealize the acidic mixture from the stomach
bile is stored in the gallbladder. when food enters the duodenum bile flows along a bileduct and is mixed with the food.

Question 31

teeth

Answer 31

bite off pieces of food
they chop, crush or grind pieces into smaller pieces
this gives the food more suface area making it easier for enzymes to break down the food later
helps only soluble molecules or ions dissolve in the watery saliva

Question 32

structure of a tooth from outer layer to inner layer

Answer 32

tooth is embedded in gum
outer layer of tooth is enamel
then dentine
then pulp
the part between the gum and tooth that holds it in place is call the cement

Question 33

enamel

Answer 33

hardest substance made by animals
hard to break or chip
can be dissolved by acid
the bacteria feed on sweet food left on the tooth these bacteria release acids which dissolves enamel and cause decay.

Question 34

dentine

Answer 34

similar to bone
hard but softer than enamel
it has channels in it which contain cytoplasm

Question 35

pulp

Answer 35

nerves and blood vessels
vessels supply the cytoplasm in the dentine with nutrients and oxygen

Question 36

cement

Answer 36

has fibres growing out of it
they attach the tooth to the jaw bone but allow it to move when biting

Question 37

amylase

Answer 37

secreted in the stomach and the pancreas
breaks starch down to multose
1 maltose molecule is 2 glucose molecules linked together
maltose is smaller than starch but still to big to be absorbed

Question 38

what enzyme is used to break down maltose

Answer 38

maltase breaks it down into glucose

Question 39

maltase

Answer 39

secreted by the cells in the lining of the small intestine called epithelium
breaks down each maltose into 2 glucose molecules

Question 40

protease

Answer 40

sectreted in the duodenum and the stomach
break down protein molecules to amino acids

Question 41

pepsin

Answer 41

a type of protease in the stomach
secreted in the stomach walls in a liquid called gastric juice
gastic juice also contains HCL that kills harmful microorganisms in food
optimum pH 2

Question 42

trypsin

Answer 42

type of protease in the duodenum
secreted in duodenum, created in the pancreas
optimun pH 7

Question 43

bile

Answer 43

fats and oils are insoluble so stay as little droplets when you eat it (in your body) they don’t mix fully into your liquid
breaks up a mix of tiny droplets into tiny ones
lipase then breaks down fat into fatty acids and glycerol

Question 44

what is emulsifying

Answer 44

physical digestion
mix of tiny floating droplets of oil

Question 45

villi

Answer 45

small finger like projections that line the inner surface of the small intestine
increases the suface area
abt 1mm long
the cell membrane is folded to make micro villi this is where maltase breaks down maltose
this is where minerals and nutrients are absorbed into the blood
most of these pass into blood capillaries inside the villus
these capillaries from all villi join a vein called the hepatic portal vein which sends everything to the liver

Question 46

in the liver

Answer 46

liver cells absorb and assimilate the substances
glucose may be stored as glycogen
amino acids are used to make different proteins
if there are more amino acids than the body requires, they will be broken down into urea and excreted.

Question 47

lacteals

Answer 47

small vessels that absorbs fatty acids and glycerol in the small intestine. their contents are eventually emptied into the blood.