6.1-6.2 Human as Heterotrophs, Food Requirements of Humans

Question 1

heterotrophs

Answer 1

humans
- feed on organic matter
- e.g. on other organisms

Question 2

autotrophs

Answer 2

plants
- synthesise it’s own food
- e.g. photosynthesis (Co2+H2o –> O2 + glucose)

Question 3

importance of food

Answer 3

food provides us
1. energy
- keep us warm
- support daily activities
2. raw materials
- growth and repair of body tissues
3. substances
- keep us healthy

Question 4

primary food substances

Answer 4

essential for life
1. carbohydrates
2. lipids
3. proteins
4. water

Question 5

protective food substances

Answer 5

keep us healthy, prevent diseases
1. vitamins
2. minerals
3. dietary fibre

Question 6

carbohydrates metabolism
(monosaccharides)

Answer 6

small, water-soluble
1. readily absorbed into intestines
2. transported to every part of the body via blood
in the cell
3. respiration occurs (glucose+O2 –> energy + Co2 + H2O) *immediate energy source

Question 7

carbohydrates metabolism
(disaccharides/polysaccharides)

Answer 7

too large, cannot be absorbed
hydrolysis into monosaccharides

disaccharides
e.g. maltose + glucose – (maltase) –> glucose + glucose

polysaccharides
e.g. starch –(amylase)–> maltose– (maltase) –> glucose

Question 8

functions of carbohydrates

Answer 8

1. main source of energy for metabolism
2. excess converted into lipids or glycogen stored in liver or under skeletal muscles
3. monosaccharides are building blocks to make larger molecules
4. cellulose in cell wall: polysaccharide
   cellulose in veggies: dietary fibre
   use? stimulate peristalsis to prevent constipation/maintain healthy digestive system