Food

Question 1

biomolecule

Answer 1

organic chemical produced and found only within living organisms

Question 2

metabolism

Answer 2

the sum of all chemical reactions in an organism

Question 3

anabolic

Answer 3

energy is required to convert smaller molecules into larger molecules eg photosynthesis, protein synthesis

Question 4

catabolic

Answer 4

energy is released to convert larger molecules into smaller molecules eg respiration, digestion

Question 5

why do we need food

Answer 5

energy source for respiration

for growth and repair of cells

Question 6

chemical elements in food

Answer 6

carbon, hydrogen, oxygen, nitrogen, phosphorous, sulphur

Question 7

salts of

Answer 7

sodium, magnesium, chlorine, potassium, calcium

Question 8

trace elements

Answer 8

iron, copper, zinc

Question 9

biomolecules

Answer 9

1. carbohydrates
2. lipids
3. proteins
4. vitamins

Question 10

carbohydrates

Answer 10

composed of carbon, hydrogen, oxygen

C6H12O6

Question 11

structural role of carbs

Answer 11

cell structure:
cellulose- found in plant cell walls
chitin- found in fungal cell walls

Question 12

metabolic role of carbs

Answer 12

glucose- broken down to release energy in respiration
glucose- stored as glycogen in animal muscles after respiration
starch- stores glucose after respiration

Question 13

types of carbs

Answer 13

monosaccaride- glucose,fructose (fruit)
disaccharide- sucrose, lactose (table sugar, milk)
polysaccharide- starch, cellulose (bread, cereal)

Question 14

lipids

Answer 14

composed of carbon, hydrogen,oxygen

general structural components: fatty acids and glycerol

Question 15

lipids examples

Answer 15

fats
oils
steroids that include cholesterol
some sex hormones`

Question 16

sources of lipids

Answer 16

butter

sunflower oil

Question 17

structural role of lipids

Answer 17

in cells: phospholipids are major components in cell membranes
in an organism: energy store/protection of organs/ heat insulation

Question 18

types of lipids

Answer 18

triglycerides- 3 fatty acids 1 glycerol

phospholipids- 1 fatty acid is replaced by a phosphate group

Question 19

sources of protein

Answer 19

lean meat, fish, eggs

Question 20

composition of protein

Answer 20

carbon, hydrogen, oxygen, nitrogen

long chains of amino acids (20) joined together by peptide bonds/polypeptide chains

Question 21

protein shapes

Answer 21

globular: lots of folding eg enzymes, albumin in egg white
fibrous: no folding eg keratin in hair and nails

Question 22

structural role of proteins

Answer 22

keratin found in hair and skin

myosin in muscles

Question 23

metabolic role of proteins

Answer 23

all enzymes are proteins: biological catalysts that control photosynthesis and respiration
hormones regulate body functions eg insulin regulates blood sugar levels

Question 24

vitamins

Answer 24

needed in small amounts, cannot be produced by the body

Question 25

vitamin c

Answer 25

``` ascorbic acid water soluble function: build connective tissue maintain bones and teeth good immune system function source: citrus fruits, green veg deficiency: scurvy symptoms: soft bleeding gums ```

Question 26

vitamin D

Answer 26

``` calciferol fat soluble function: needed to absorb calcium from food forms bone source: dairy fish liver oil, egg yolk deficiency: rickets in children osteomalacia in adults symptoms: bones lose calcium and become weak bones break easily ```

Question 27

minerals

Answer 27

inorganic and required in small amounts plants absorb minerals through roots animals get their minerals from food they eat

Question 28

calcium (plant)

Answer 28

to form middle lamella between cells (cell wall)

Question 29

magnesium (plant)

Answer 29

to form part of chlorophyll

Question 30

calcium (animal)

Answer 30

forms bone and teeth

Question 31

iron (animal)

Answer 31

forms part of haemoglobin

Question 32

water

Answer 32

cells and body fluids are made of 70% water in animals, 90% in plants

Question 33

importance/uses of water

Answer 33

universal solvent that transports substances in plants or blood, allows substances to move between membranes Where all metabolic reactions take place: component of cytoplasm, controls shape of cell by osmosis It is a reactant/product in chemical reactions: source of oxygen produced in photosynthesis

Question 34

to test for starch

Answer 34

iodine solution and starch solution | blue/black if present, red/brown if not

Question 35

to test for a reducing sugar

Answer 35

benedicts solution and glucose | brick red if present, stays blue if not

Question 36

to test for fat

Answer 36

brown paper and oil | translucent if present, not if not

Question 37

to test for protein

Answer 37

biuret reagent and milk | purple if present, blue if not