Категории: Все - carbohydrates - glucose - photosynthesis - proteins

по yoshe watson 16 лет назад

371

YOSHE-Biology - Animal Survival-the need for food

Animals and plants have essential needs for survival, particularly the necessity for food, which provides energy and raw materials for growth. Carbohydrates, fats, and proteins are the main chemical components of food.

YOSHE-Biology - Animal Survival-the need for food

Biology - Animal Survival(the need for food)

chemical structure of food types

proteins
basic units they are built from-amino acids
elements present-carbon, oxygen, hydrogen, nitrogen
fats
basic units they are built from-fatty acids and glycerol
carbohydrates
basic units they are built from-glucose molecules
elements present-carbon, oxygen, hydrogen

chemical tests

for starch
2/ solution will turn blue/black if starch is present
1/ add 2 drops of brown iodine solution to food solution
for glucose
3/ if glucose is present, an orange precipitate will form
2/ heat in a water bath until it boils
1/ add a few drops of blue benedicts solution to food solution

main chemicals in foods

fats-store energy, insulation, make cell membranes
proteins-growth and repair
carbohydrates eg sugar and starch-provide energy

how organisms obtain their food

animals-eat plants or other animals
plants-make their own food by photosynthesis

why we need food-a source of raw materials for growth and as a source of energy.