Ch1 Cellulose, starch and glycogen

Question 1

Test for starch

Answer 1

1. Add iodine solution
2. Shake or stir
3. Colour change from yellow to blue-black

Question 2

Structure of starch

Answer 2

1. Coiled and compact
2. Chains are branched and unbranched
3. Polysaccharide of alpha glucose
4. Found in plants(seeds and storage organs)

Question 3

5 starch adaptations for energy storage

Answer 3

1. insoluble- doesn’t affect water potential and osmosis
2. large so can’t diffuse out of cell
3. compact- large amount of energy in small space
4. branched- large surface area to be broken down by enzymes into…
5. alpha glucose monomers- readily broken down for respiration

Question 4

Glycogen structure

Answer 4

1. Short chains
2. Highly branched
   3.Found in muscles and liver

Question 5

Glycogen adaptations for energy storage

Answer 5

1. insoluble- doesn’t affect water potential and osmosis
2. large- can’t diffuse out of cell
3. compact- large amount of energy in small space
4. highly branched- large surface area to be broken down by enzymes into…
5. alpha glucose monomers- readily broken down for respiration

Question 6

Cellulose structure

Answer 6

1. beta glucose monomers
2. straight unbranched chains
3. cross-linkages between parallel chains(hydrogen bonds)
4. grouped to form microfibrils which group in fibres

Question 7

Cellulose functions

Answer 7

1. provides rigidity in plant cell wall
2. exerts inward pressure that stops influx of osmotic water and bursting
3. maintains stem and leaves in turgid state for large SA for photosynthesis

Question 8

starch vs glycogen

Answer 8

starch is more highly branched